Astronomy_News_20_09_2020
Astronomy_News_20_09_2020
This months research Papers 20_09_2020
RASNZ_20_09_2020
Further links and discussion can be found at the groups/links below
Astronomy in New Zealand - Facebook
https://www.facebook.com/groups/5889909863/
Astronomy in New Zealand - Groups.io
https://groups.io/g/AstronomyNZ
Google Group
https://groups.google.com/g/nzastrochat
Astronomy in Wellington
https://www.facebook.com/groups/11451597655/
Blogger Posts
http://laintal.blogspot.com/
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Research papers
On The Biomass Required To Produce Phosphine Detected In The Cloud Decks Of Venus
Authors: Manasvi Lingam, Abraham Loeb
https://arxiv.org/abs/2009.07835
Feasibility Analysis and Preliminary Design of ChipSat Entry for In-situ Investigation of the Atmosphere of Venus
https://arxiv.org/abs/2009.08396
Transfer of Life Between Earth and Venus with Planet-Grazing Asteroids
https://arxiv.org/abs/2009.09512
Seeing above the Clouds with High Resolution Spectroscopy
https://arxiv.org/abs/2008.11464
Estimating the Ultraviolet Emission of M dwarfs with Exoplanets from Ca II and Ha
https://arxiv.org/abs/2009.07869
Water Vapor and Clouds on the Habitable-Zone Sub-Neptune Exoplanet K2-18b
https://arxiv.org/abs/1909.04642
Callisto
https://arxiv.org/abs/2009.05002
Accretion disk's magnetic field controlled the composition of the terrestrial planets
https://arxiv.org/abs/2009.04311
Stellar Flares versus Luminosity XUV-induced Atmospheric Escape and Planetary Habitability
https://arxiv.org/abs/2009.04310
A kilometer-scale asteroid inside Venus's orbit
https://arxiv.org/abs/2009.04125
Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES
https://arxiv.org/abs/2009.01841
How massive can a black hole be? This study asked that question and takes a look at how many there could be.
Black holes – Do they grow stupendously large?
https://astrobites.org/2020/09/05/stupendously-large-black-holes/
Constraints on Stupendously Large Black Holes
https://arxiv.org/abs/2008.08077
Direct Imaging Discovery of a Young Brown Dwarf Companion to an A2V Star
https://arxiv.org/abs/2009.08537
The High-Energy Radiation Environment Around a 10 Gyr M Dwarf
https://arxiv.org/abs/2009.01259
Utilizing a Database of Simulated Geometric Albedo Spectra for Photometric Characterization of Rocky Exoplanet Atmospheres
https://arxiv.org/abs/2009.01330
Cryogenic Cometary Sample Return
https://arxiv.org/abs/2009.00101
Habitable Zones in Binary Star Systems
https://arxiv.org/abs/2009.00144
The Equatorial Jet Speed on Tidally Locked Planets
https://arxiv.org/abs/2009.00358
A Recipe for Geophysical Exploration of Enceladus
https://arxiv.org/abs/2008.02887
The effects of granulation and supergranulation on Earth-mass planet detectability
https://arxiv.org/abs/2008.11952
Lithologic Controls on Silicate Weathering Regimes of Temperate Planets
https://arxiv.org/abs/2008.11620
Evolution of the Earth's Polar Outflow From Mid-Archean to Present
https://arxiv.org/abs/2008.10337
The impact of the planetesimal surface density in the terrestrial planet zone
https://arxiv.org/abs/2008.10432
Alien skies
https://www.drewexmachina.com/2020/08/28/alien-skies-the-view-from-alpha-centauri/
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Interesting News items
The British Astronomical Association (BAA) did a webinar about Comet NEOWISE a few days ago. It can be seen on YouTube at -
https://www.youtube.com/watch?v=G6xlpvxJTYQ
Camera retailer who swindled more than $100,000 from customers jailed
https://www.stuff.co.nz/timaru-herald/news/122804586/camera-retailer-who-swindled-more-than-100000-from-customers-jailed
Gobekli Tepe: The world’s first astronomical observatory?
https://astronomy.com/news/2020/09/gobekli-tepe-the-worlds-first-astronomical-observatory
Dark sky reserve moving forward
https://times-age.co.nz/dark-sky-reserve-moving-forward
Dark Sky Maps
https://blue-marble.de/nightlights/2019
New Zealand Tasmanian tiger pelt provides DNA of extinct marsupial
https://www.rnz.co.nz/news/national/424807/new-zealand-tasmanian-tiger-pelt-provides-dna-of-extinct-marsupial
A Supercomputer Analyzed Covid-19 — and an Interesting New Theory Has Emerged
https://elemental.medium.com/a-supercomputer-analyzed-covid-19-and-an-interesting-new-theory-has-emerged-31cb8eba9d63
A mechanistic model and therapeutic interventions for COVID-19 involving a RAS-mediated bradykinin storm
https://elifesciences.org/articles/59177
Intensive Care Unit Admission and Mortality Among Patients Hospitalized for COVID-19
https://www.sciencedirect.com/science/article/pii/S0960076020302764
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Updates from Andrew B,
Enceladus.
Five views of the Saturn moon Enceladus with the VIMS / Visible and Infrared Mapping Spectrometer on board the Cassini Spacecraft. VIMS was sensitive to both visible light and infrared light. The VIMS collected both visible and infrared light and split it into it's constituent wavelengths and detected surface chemical and mineral compositions on the moons of Saturn, Saturn's rings as well as condensates in Saturn's atmosphere. The VIMS also measured temperatures.
Red = warmer, blue = colder.
The enhanced warmth in the south polar regions on Enceladus within the 'Tiger Stripes' . The Tiger Stripes were named: Alexandria Sulcus, Cairo Sulcus, Baghdad Sulcus and Damascus Sulcus, cities within the Arabian Nights, with Cairo, Baghdad and Damascus being the capital cities of Egypt, Iraq and Syria respectively and Alexandria being an important port city of Egypt on the shores of the Mediterranean Sea.
The Tiger Stripes are the locations of the geysers in the far south of Enceladus, around the south pole of the small Saturn moon.
Enceladus is the fourth smallest of the ‘classical’ longer known moons of Saturn, only Mimas, Hyperion and Phoebe are smaller.
Enceladus is 513 KM / 319 miles (long axis towards Saturn) by 503 KM / 312 miles (east to west) by 497 KM / 309 miles (through the poles north to south) in size. Enceladus is the second smallest known object in the solar system to be rounded by hydrostatic equilibrium, the mass and gravity to overcome the structural strength of the constituent materials. Only the inner neighbouring Saturn moon Mimas is known to be smaller to be rounded by such a mechanism.
Enceladus orbits Saturn once every 1 day, 8 hours & 53 minutes. The rotational period is the same, so Enceladus keeps the same face turned towards Saturn as our own Moon does with Earth. Dione orbits Saturn at an average distance of 237,948 KM / 147,767 miles.
Enceladus is in orbital resonance with the much larger Dione, for every one orbit Dione makes around Saturn, Enceladus makes two.
With a mean density of 1.61 G-CM3 and a diameter of only 503 KM / 312 miles, Enceladus is dense enough to have a great deal of rock with a global mass of about 55% rock - 45% ice, gravity data from the repeated close passes of the Cassini spacecraft revealed a differentiated object with a distinct core, ice mantle and ice crust, possible regional subsurface southern ocean.
Despite the very high rock content, such a small body would not have enough radioactive isotopes left (would have done in the early days of the Saturn system) to keep the interior warm enough to drive geological activity. Iron 60 which is very radioactive and would certainly have been present has a very short half life of only 2.6 million years and aluminium 26 even worse at only 717,000 years!!!! Whist traces of both are still present for sure inside Enceladus, they are so low now that they are barely worth considering. The amount of Uranium and Thorium would also be likely too small to maintain the current activity too.
Enceladus is certainly being kept warm internally by tidal, frictional heating between Saturn and the much larger moons of Tethys and Dione further out. Tethys has about 6 times the mass of Enceladus, Dione about 11 times. It's just that the full mechanism still needs to be worked out, I can assure you with mass v volume, Enceladus does not have enough radioactive materials for large scale internal heating.
Enceladus experiences surface temperatures of Summer maximum of minus 128 Celsius / minus 198 Fahrenheit or 148 Kelvin & a global average of minus 198 Celsius / minus 324 Fahrenheit or 75 Kelvin.
Enceladus Winter / early Spring surface temperatures plummet to a minimum of minus 240 Celsius / minus 400 Fahrenheit or 33 Kelvin, even lower than the mean surface temperatures of Pluto, Charon and the Neptune moon Triton (though they all known to have lower minimum temperatures). Enceladus has seasons lasting approximately 7.5 years as it shares, Saturn’s years of 29.5 Earth years and axial tilt of approximately 27 degrees.
Enceladus is a varied world, despite the small size. The terrain is certainly older in the northern hemisphere, impact craters are softened and there are huge canyons though mostly not ancient. The southern hemisphere is less cratered, some smoother plains and huge canyons with active geysers, spraying out ice particles, many of these and up in orbit around Saturn, making up the E-Ring, many though make it back down onto Enceladus making the surface extremely reflective, making Enceladus the most reflective known body in the solar system, only the KBO / dwarf planet Eris and Neptune moon Triton comes close.
Recently a claim was made that the long suspected subsurface ocean under the ice crust and above the rocky mantle was confirmed.
Text: Andrew R Brown.
NASA/JPL-CalTech/Space Science Institute/ESA. Cassini Spacecraft.
Venus.
Imaged: Friday 8th February 1974. Mariner 10.
Imaged: Monday 1st March 1982. Venera 13.
Imaged: Friday 5th March 1982. Venera 14.
First image: Venus seen here in ultraviolet light by the then receding Mercury bound Mariner 10 spacecraft.
Second and third images, surface views taken by the then Soviet Union's Venera 13 and Venera 14 spacecraft.
A striking claim that Prof Jane Greaves, from Cardiff University, UK and also Professor Sara Seager from Massachusetts Institute of Technology, USA by using reflected radio waves from Venus have detected the gas Phosphine. The Sun emits radiowaves as well as visible, ultraviolet and infrared. Fromm infrared the elecromagnetic spectrum continues into microwaves and then into radio.
Prof Greaves's team first identified Phosphine at Venus using the James Clerk Maxwell Telescope in Hawaii, USA and then confirmed its presence later using the Atacama Large Millimeter/submillimeter Array in Chile, and this confirmed the existence of Phosphine in the atmosphere of Venus.
Venus reflects some of the radiation reaching it, including radio. At radio wavelength 1mm (EHF: Extremely High Frequency or MMW: MilliMetre Wave or Microwave, the wavelength used to heat ready meals, etc), Venus appears almost invisible, These are absorbed at that particular wavelength of Phosphine and only Phosphine.
Phosphine is a molecule made from three Hydrogen atoms (one proton and one electron, element # 1, atomic weight 1) and one atom of Phosphorus (fifteen protons, fifteen neutrons and fifteen electrons, element # 15, atomic weight 31). The Phosphine had been detected in the clouds some 51 KM / 32 miles above the torrid surface of the Second Rock from the Sun.
It had been speculated that within the top half of the cloud decks where temperatures are about 21 Celsius / 71 Fahrenheit to 35 Celsius / 95 Fahrenheit there may be sulphuric acid feeding microbes, though I think that this is not the case as on Earth, life seems to need more than just clouds (our clouds contain bacteria, but that has originated on the surface and been swept up by winds and air currents. Venus's surface conditions would sterilize everything).
Or to this week, that was the idea. Phosphine has a mostly biological origin, a waste product of bacteria in anerobic (oxygen free) environments. Whist Phosphine can be produced by other chemical reactions of gases emmited by volcanoes, etc, it is in such tiny quantities only about 1 part in 10,000 from non biological origins as compared to biological origins.
The biggest mysteries are now, is the Phosphine in Venus's clouds of biological origin, quantities suggests yes. Phosphine breaks down very quickly, in seconds, so it it being produced continuously.
How does the bacteria / virus manage to protect itself, from the very low PH, very high acidic environment of the sulphuric acid clouds?
Also what is it's biogenesis? Did it arrive on dust, asteroids and comets entering Venus's atmosphere or did it come from possible life on the surface during the early days of the solar system when Venus was most likely far more habitable, with lakes, before the runaway greenhouse effect took over as well as mass eruptions of lava? Perhaps these are descendants from that earlier time.
Here the cloudtops are seen blowing to the west at about 320 KPH / 200 MPH taking four days to circle the planet, with relation to the main physical planet. At the surface, winds are very slow, but at the tropopause of Venus (boundary of Venus's troposphere and stratosphere), they are fast. Venus rotates very slowly from east to west (the opposite way to the Earth and most other planets, except Uranus and Pluto). Venus rotates at a speed of only 6.5 KPH / 4.0 MPH at the equator, where as Earth rotates at a speed of 1,674 KPH / 1,040 MPH at the equator.
The surface temperature on Venus averages 464 Celsius / 867 Fahrenheit, under a crushing atmosphere some 92 times denser than Earth's, composed of 96.5 % Carbon Dioxide and most of the rest is nitrogen. The sulphuric acid laden clouds are very high above the surface, in places their cloud bases are some 40 KM / 25 miles above the scorched, arid lava plains. From these cloud bases, the curvature of Venus would be clearly visible.
There is evidence, though not 100% confirmed that Venus has lightning. Radio whistler waves had been detected by various spacecraft that passed by like the Jupiter bound Galileo, Saturn bound Cassini and Mercury bound MESSENGER as well as the European Venus Express orbiter, but visual proof is lacking. Radio whistler waves are generally emitted by lightning (it's what temporarily ruins your radio and television reception when lightning is near). These could be from volcanic plumes and / or thunderstorms within Venus's clouds. There may also be sulphuric acid laden rain (there is evidence but also not 100% confirmed), which in places falls from the clouds, but it evaporates well before it gets anywhere near the surface, so not a drop of this poison rain ever touches solid ground.
The very cloud tops themselves are quite cold at about minus 33 Celsius / minus 27 Fahrenheit with ice crystals. This make Venus highly reflective in the visible part of the spectrum, hence from Earth, Venus appears so incredibly bright, sometimes before sunrise (morning star) or after sunset (evening star) and is often visible in full daylight.
Venus rotates from east to west once every 243 Earth days, the rotation period is longer than it takes for Venus to orbit the Sun once every 224 days, at an average distance of 108.2 million KM / 67.2 million miles from the Sun, (so New Year's Eve on Venus would be on 14th August, assuming we superimposed the orbital period of Venus on an Earth calendar, starting on 1st January).
Because of the very slow rotational period, retrograde (east to west) direction and short year on Venus, sunrise to sunrise is separated by 116 days & 18 hours, with the sun (appearing about twice as large and bright than from Earth, but from the surface, lighting and contrast levels are about the same as a dull, very overcast day with thick cloud in the UK) very slowly rising in the west, crawling across the sky and slowly setting in the east some 58 days & 9 hours later, followed by an equally long night. This however is a moot point as the skies are permanently overcast from the surface. Also surface temperatures do not drop during the long Cytherian nights, as that dense CO2 atmosphere and constant thick cloud cover acts like a giant thermos flask, trapping heat, in but also prevents extra heat from building up from the long Cytherian days.
Venus with a diameter of 12,104 KM / 7,521 miles, with a mass of 4,867.5 billion trillion tons (4,867.5 followed by twenty zeros) with a mean density of 5.243 G/CM3 is really the Earth's twin in terms of planetary mass, size and density, suggesting Venus & Earth share a common origin. Our own Earth with a diameter of 12,742 KM / 7,917 miles, with a mass of 5,972.2 billion trillion tons (5,972.2 followed by twenty zeros) and a mean density of 5.517 G/CM3.
Venus's surface consists of about 85% basaltic lava plains, there are mountains, the tallest of which within Maxwell Montes (a huge mountainous massif in the northern hemisphere on Venus) of which Skadi Mons is the tallest peak, towers some 10,700 metres / 35,105 feet above the general lava plains, somewhat taller than our own Mount Everest which rises to 8,848 metres / 29,029 feet above mean sea level.
The conditions at the summit of Skadi Mons are quite tame as compared to the genral lowland lava plain surface, but still about 42 atmospheres pressure and a temperature of about 380 Celsius / 716 Fahrenheit!!!!
Venus has volcanoes, lots of them, there is evidence that some are active, though not 100% certain. There are very strange coronae, huge circular features some in excess of 500 KM / 311 miles wide within the lava plains with deep, narrow canyons surrounding some of them.
One of the strangest things is that Venus despite it's dense, crushing atmosphere, has impact craters. The general distribution and low density of them (that dense atmosphere will prevent many larger impactors from hitting the surface than Earth's atmosphere would) fairly evenly over the entire surface, suggests that Venus periodically 'resurfaces itself' with fresh lava in massive volcanic eruptions, totally covering the lava plains, that lasts for hundreds of thousands, if not for over a million years.
There is some doubt on this now (perhaps resurfacing goes on all the time at a more sedate pace), but it still remains a possibility, owing to the even distribution (more sedate eruptions would resurface locally first, then spread out, this would be hard to explain with the current distribution of craters). If the former scenario is correct, then Venus is currently going through a 'quiet phase' between massive episodes of mass volcanism with only minor eruptions during our time.
Text: Andrew R Brown.
NASA / JPL-Caltech. Mariner 10 spacecraft.
Lavochkin. Venera 13 & Venera 14 landers.
Donald Mitchell. Cleaned up and reprojected the Venera images from the originals.
Comet C/2020 F3 NEOWISE.
Imaged: Saturday 8th August 2020.
Full colour view of Comet C/2020 F3 NEOWISE, from the Earth orbiting Hubble Space Telescope.
Whilst the comet was too close to the Sun to be viewed by the Hubble Space Telescope throughout June & July, in August as the comet was receding from both the Sun and the Earth, the Hubble Space Telescope obtained this view, one of the highest resolution views of the inner coma, around the comet's tiny 5 KM / 3.1 mile wide nucleus.
The two fan like structures on either side are from jets of gas, ice crystals and dust erupting from the nucleus and these observations revealed that the nucleus is rotating on it's side (much like the planet Uranus, Asteroids 7 Iris, 21 Lutetia, 433 Eros etc) about once every 7.5 hours.
Retrograding comet, orbits the Sun in the opposite direction to the planets.
Approximate orbital period around the Sun: 6,953 years.
Perihelion, closest to the Sun: 44.25 Million KM / 27.50 Million miles. Slightly closer than the minimum distance from the Sun to Mercury.
Aphelion, furthest from the Sun: 109.241 Billion KM / 67.879 Billion miles. About 22 times the Sun to Pluto average distance.
Comet C/2020 F3 NEOWISE passed Earth on: Thursday 23rd July 2020 at a distance of: 103 Million KM / 64 Million miles.
Text: Andrew R Brown.
NASA / JPL-Caltech / STScI Hubble Space Telescope.
Mars.
A view of the western part including the delta (the landing site of the currently on route NASA / JPL-Caltech, Mars Perseverance Rover) at Jezero Crater seen by the European Space Agency Mars Express spacecraft, using the HRSC / High Resolution Stereo Camera.
As the beautiful spacecraft containing the Mars Perseverance Rover and the experimantal Ingenuity Helicopter is safely on course for Mars after such an awesome launch and in spite of a very short period of safing which was quickly diagnosed and solved, the Perseverance Rover is in great health and all is continuing to go very well indeed.
The Mars Perseverance Rover on Thursday 18th February 2021 @ about 20:00 hrs GMT is due to land in the 49 KM / 30.5 mile wide impact Jezero Crater within the Syrtis Major Quadrangle at 18.38°North & 77.58°East. Jezero Crater is located on the north west rim of the 1,500 KM / 930 mile wide Isidis Planitia. Isidis Plantia formed inside a martian Noachian Period 4.1 to 3.7 GYO (GYO = Giga Year Old or 1 Giga Year is 1 billion years or 1 thousand million years) impact basin that filled with lava, then hosted a sea, before that was lost to space.
The centre of Isidis Planitia was the landing site for the ill fated British Beagle 2 lander that landed on Thursday 25th December 2003 / Christmas Day 2003.
Jezero Crater is named after a town and district called Jezero within the former Yugoslav Republic of Bosnia and Herzegovina. Also in the slavic languages of Serbo-Croat, Bosnian, Slovene and Czech, Jezero means Lake.
Jezero Crater was chosen or rather a small area just inside the west rim as there is an ancient, long since dried out river delta with a river flowing from the west. An outflow channel drained from the east rim. However a lake formed within the impact crater.
The delta formed from sediments carried by the former river and from sediments from channels within Nili Fossae to the north west.
River deltas on Earth such as the Amazon Delta, Brazil, the Nile Delta, Egypt and the Mississippi Delta, Louisiana, USA, etc contain minerals and rock fragments from the areas the rivers flowed though as well as microbes and remains of other living organisms.
The site chosen for the Mars Perseverance Rover is absolutely incredible. From orbit Compact Reconnaissance Imaging Spectrometer for Mars / CRISM on board the Mars Reconnaissance Orbiter, the Thermal Emission Imaging System / THEMIS on board the Mars Odyssey 2001 orbiter (by far the oldest operating spacecraft at Mars, 19 years and counting) as well as from the European Space Agency Mars Express orbiter (whose observations helped nail the centre of the landing ellipse for the Mars Perseverance Rover team). Various observations have revealed the presence of carbonate rocks, which on Earth often preserve evidence of organic life, possibly microfossils. Olivine aka Peridot from volcanic activity has also been detected. The whole area needless to say is full of hydrated minerals.
The delta is very old as expected, about 3.5 GYO formed during the early martian Hesperian Period (3.7 to 2.9 billion years ago). This was just before the time Mars started to lose it's atmosphere and temperatures where starting to drop.
Text: Andrew R Brown.
HRSC / High Resolution Stereo Camera.
ESA/Freie Universitat Berlin. Mars Express Orbiter.
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RASNZ
Royal Astronomical Society of New Zealand
eNewsletter: No. 237, 20 September 2020
Affiliated Societies are welcome to reproduce any item in this email newsletter or on the RASNZ website www.rasnz.org.nz in their own newsletters provided an acknowledgement of the source is also included.
Contents
1. Dark and Quiet Skies Workshop
2. Online Presentations in Lieu of the In-person 2020 Conference
3. Conference Committee Members Needed
4. The Solar System in October
5. Variable Star News
6. A Date for Matariki?
7. Wairarapa Dark Sky Reserve the World's Biggest?
8. Moon Effects on Life?
9. Life on Venus?
10. Dark Matter Problem?
11. Covid Quotes
1. Dark and Quiet Skies Workshop
You are invited to participate in the online Workshop on “Dark and Quiet Skies for Science and Society” between October 6-9, 4 a.m. to 6 a.m. NZDT.
It is being organised by the United Nations Office for Outer Space Affairs, the International Astronomical Union and Astrophysics Institute of the Canary Islands. Most of the Workshop will also be recorded for later viewing and commenting by people outside the time zones. The online workshop will present initial findings from five working groups of the Scientific Organising Committee (SOC), for discussion. Within the two hour period, presentations will first be made by the SOC and open discussions will follow.
The purpose and scope of the Workshop are to propose to the Committee on the Peaceful Uses of Outer Space's Scientific and Technical Sub-Committee a set of recommendations to protect the science of astronomy. They will be acted upon either by local governments or agreed at the international level.
Anyone can register for free at http://research.iac.es/congreso/quietdarksky2020/.
The conference is entirely virtual and will be live streamed over Zoom.
There are five main topics as follows, so five days of talks.
Dark sky oases
Bio-environment and light pollution
Astronomical observatories and light pollution
Satellite constellations and their impact on astronomy
Radio-astronomy and the problem of radio noise
Advances in space astronomy have contributed great strides in our knowledge of the universe. However, space astronomy has not made ground observatories obsolete, because data obtained by space instruments are pathfinders to the larger, more numerous ground telescopes that complete the scientific modelling of celestial phenomena. It is this perfect synergy that allows us to successfully unveil the physical reality of the cosmos. The information that we acquire from the study of celestial phenomena has always been instrumental to a deeper understanding of physical reality, which in turn is fundamental for any technological progress. It is therefore in the interest of all sectors of society to enable astronomy to benefit from access to the open windows on the sky and in the electromagnetic spectrum.
We must not forget that, beyond science and technology, the pristine spectacle of the starry night sky has been inspirational to humankind since prehistoric times and this world cultural heritage should be zealously protected.
John Hearnshaw is co-chairing the dark sky oases working group, which is presenting on the first day of the workshop (at 4 am Oct 6, NZDT).
2. Online Presentations in Lieu of the In-person 2020 Conference
An online series of talks as a substitute for the in-person conference is being arranged. The idea is to have weekly sessions, probably on a mid-week evening, with each lasting about an hour and consisting of up to three talks. Most of the presentations will be live but a couple of recorded talks will be included.
The programme is likely to start late October and carry on into November; details are being worked on and we expect to announce the content and date for each session in the near future.
The only software you will need to watch these sessions is a web browser and all talks will be made available for later viewing on YouTube or similar platform.
-- Glen Rowe, Warwick Kissling
3. Conference Committee Members Needed
RASNZ President Nick Rattenbury writes:
I hope that you all are taking care of yourself and yours during these
rather trying times. If you are like me, you are probably feeling a little stretched trying to manage home, work and recreation in what can charitably be called uncertain times. However, I am asking for your help. At the next Annual General Meeting of the Royal Astronomical Society of New Zealand, a substantial fraction of the Standing Conference Committee will be standing down. We, as a Society, need to fill these positions. Will you volunteer your time for your Society and serve on the SCC?
The Annual RASNZ Conference is the Society´s most visible event and is the opportunity for NZ and international astronomers to meet and share our research, findings, challenges and the thrill of discovery that astronomy brings. The SCC acts as a `scientific organising committee´, has oversight of the RASNZ Affiliated Society that runs each conference and is ultimately responsible to RASNZ Council. The roles and responsibilities of the SCC are attached.
In these interesting times, many of us have had to learn how to run our
businesses and our social interactions according to some new rules. This
has required us all to show a higher degree of flexibility, innovation and a willingness to try new things or adopt more resilient processes as a result. Council is looking for volunteers to serve on the SCC who are keen to leverage new technologies to allow us as a Society to remain connected in what could be an extended period of remote interaction.
If you have any questions about the role of the SCC, please do not hesitate to contact me (president@rasnz.org), or the current Chair of the SCC, Glen Rowe (growe511@outlook.com).
Yours faithfully,
Dr Nicholas Rattenbury
President, RASNZ
4. The Solar System in October
Dates and times shown are NZDT (UT + 13 hours). Rise and Set times are for Wellington. They will vary by a few minutes elsewhere in NZ. Data is adapted from that shown by GUIDE 9.1
THE SUN and PLANETS in OCTOBER, Rise & Set, Magnitude & Constellation
OCT 1 NZDT OCT 30 NZDT
Mag Cons Rise Set Mag Cons Rise Set
SUN -26.7 Vir 6.52am 7.28pm -26.7 Lib 6.06am 8.03pm
Merc -0.0 Vir 7.41am 9.45pm 1.8 Vir 5.41am 6.54pm
Venus -4.1 Leo 5.19am 4.03pm -4.0 Vir 4.51am 5.05pm
Mars -2.5 Psc 8.33pm 7.57am -2.2 Psc 5.56pm 5.30am
Jup -2.4 Sgr 12.25pm 3.28am -2.2 Sgr 10.42am 1.41am
Sat 0.5 Sgr 1.03pm 3.53am 0.6 Sgr 11.09pm 1.58am
Uran 5.7 Ari 9.55pm 8.21am 5.7 Ari 7.51pm 6.19am
Nep 7.8 Aqr 5.36pm 6.22am 7.8 Aqr 3.35pm 4.23am
Pluto 14.5 Sgr 12.45pm 3.47am 14.5 Sgr 10.48pm 1.50am
OCTOBER 1 NZDT OCTOBER 30 NZDT
Twilights morning evening morning evening
Civil: start 6.27am, end 7.55pm start 5.39am, end 8.31pm
Nautical: start 5.55am, end 8.27pm start 5.03am, end 9.07pm
Astro: start 5.21am, end 9.01pm start 4.24am, end 9.46pm
OCTOBER PHASES OF THE MOON, times NZDT & UT
Full Moon: OCT 2 at 10.05am (Oct 1, 21:05 UT)
Last quarter: OCT 10 at 1.39pm (00:39 UT)
New Moon: OCT 17 at 8.31am (Oct 16, 19:31 UT)
First quarter: OCT 24 at 2.23am (Oct 23, 13:23 UT)
Full Moon: Nov 1 at 3.49am (Oct 31, 14:49 UT)
THE PLANETS in OCTOBER
MERCURY starts the month at its greatest elongation, 26° east of the Sun. As a result it will be well placed (for Mercury) for evening viewing with an altitude 13° an hour after sunset. With a magnitude 0.0 it should be an easy object just south of due west.
After its greatest elongation the planet's motion slows so that its distance from the Sun begins to decrease. But Mercury is still 20° from the Sun when stationary on the 14th. After that the planet starts moving back towards the Sun so that their separation rapidly decreases.
By October 26 the planet is at inferior conjunction between the Sun and Earth, when it is less than a degree from the Sun. For the rest of October the planet becomes a morning object rising before the Sun, but is too close to the Sun to observe.
VENUS is a morning object easily visible to the northeast an hour before sunrise, although rather low. Early in the month it passes close to the 1.4 magnitude star Regulus. On the morning of the 3rd they will be about a quarter degree apart an hour before sunrise. They are closer during daylight hours near midday with a 5 arc-minute separation.
The crescent moon is some 4° from Venus, on the 14th the two being closest about 5 pm NZDT. Their closest approach visible from New Zealand is in the early morning of the 14th when the two are some 7° apart.
MARS is slightly brighter than Jupiter for most of the month. It starts October at magnitude -2.5 with Jupiter at -2.4.
The planet is closest to the Earth on the night of 6/7 October, 62.1 million km, 0.41 AU, from the Earth. It is at opposition a week later. Mars will then be 62.7 million km, 0.42 AU away. Mars's magnitude will be 2.6 on these dates. By the end of October it will be a similar brightness to Jupiter, both at 2.2.
JUPITER and SATURN are well placed in the evening sky during October. They start the month just over 7° apart with Jupiter leading the way across the sky, but closing in on Saturn as the month progresses. By the end of the month they are 2° closer.
The first quarter moon will be just over 2° from Saturn early evening on the 23rd.
PLUTO remains between Jupiter and Saturn during October, now somewhat closer to Jupiter. At magnitude 14.5 it will only be visible in a moderate telescope.
URANUS is in Aries, rising during the evening in October. The moon, less than 3 days after being full, is just under 3° from the planet at about 11pm on October 4, while the two are fairly low. At magnitude 5.7, Uranus is an easy binocular object
NEPTUNE rises before sunset so is well up by the time the sky darkens. Its encounter with the moon is on the 27th, the two are closest at about 10 pm. The moon, three days short of full, will then be about 3.5° from the planet
POSSIBLE BINOCULAR ASTEROIDS in OCTOBER
OCT 1 NZDT OCT 30 NZDT
Mag Cons transit Mag Cons transit
(1) Ceres 8.2 PsA 11.07pm 8.7 Aqr 9.05pm
(4) Vesta 8.4 Leo 10 16am 8.2 Leo 9.04am
(8) Flora 8.6 Cet 3.41am 8.0 Cet 1.23am
CERES is in the evening sky. It moves from Piscis Austrinus to Aquarius mid-month and is stationary on November 23
VESTA is a morning object rising about 100 minutes before the Sun on the 1st and about 140 minutes before on the 31st. It starts October 7° from Venus but the latter steadily pulls away from the asteroid over subsequent evenings during the month.
FLORA has two close encounters with bright stars in Cetus during October. It starts the month 1.35° from the 2.5 magnitude star Menkar, alpha Ceti. The two are closest, just under 1° apart on the 8th and 9th, when they rise about 9.30 pm. On the 9th, at about 11 pm, Flora will be to the left of Menkar. The two will then be about 17° up to the east-north-east.
On the night of October 30/31, Flora passes very close to the binary star gamma Cet, Kaffaljidhma. The pair of stars have magnitudes 3.5 and 6.1 with a separation 2.5 arc-second. Flora and the star are closest about 3:50am on the 31st, with a separation 3.2 arc-minutes. By then Flora will be near opposition at magnitude 8.0 making it temporarily the brightest asteroid
-- Brian Loader
5. Variable Star News
A research project on pulsating red giant stars is being undertaken at University of Canterbury (UC) Mt John Observatory by Rosemary Dorsey as part of her M.Sc. degree in Astronomy. She will be using the 1.0-metre telescope and the high resolution Echelle spectrograph, which was designed and built at UC, to determine the velocities of shells in the star’s atmosphere during expansion and contraction. This is part of an on-going research project in the Physics and Astronomy department
During her secondary school education Rosemary developed a great interest in astronomy and took up study at UC to further her knowledge. She is attracted by stellar astronomy which appeals to her as there are immediate gains in knowledge that can be made. The spectrographic measurements will determine the velocities of the shells of gas in the star atmospheres and allow determination of the modes of pulsation of the stars.to test models of star structures.
During her graduate study Rosemary was awarded physics prizes and scholarships. She is supported in her Masters study by a grant from the Dennis William Moore scholarship which was established from a bequest in 1999 to fund activities and projects related to astronomy at UC. She plans to continue her research career with a PhD under Dr Michele Bannister.
Details of Rosemary’s study abstracted from Te Whare Wananga o Waitaha
University of Canterbury (UC) Foundation Report 2019, pp 18-19.
-- Alan Baldwin
6. A Date for Matariki?
Matariki has become a widely accepted festival across the country. NZ News media organisation Stuff says it's time for a Matariki statutory holiday to mark the occasion. There’s no single day that marks Matariki, so when could a public holiday celebrating the Maori New Year fall?
On September 7 Labour announced plans to create a Matariki public holiday in 2022 if re-elected. Stuff launched a campaign for the holiday back in July, arguing we were overdue the creation of a unifying holiday that honours Aotearoa’s past and celebrates New Zealand’s future. But unlike the December/January New Year, there’s no single day that marks the Maori New Year period.
Forcing a specific annual date might defeat the purpose of the season, according to Dr Dan Hikuroa, a senior lecturer for the University of Auckland's Te Wananga o Waipapa. “[That] wouldn’t be in keeping with the way Matariki itself is.” So why not make it moveable? It’s an idea that has the support of a number of experts, advocates and iwi – including Hikuroa. We already do it for Easter, Te taiwhenau o heretanga’s board chairman Mike Paku commented.
“New Zealanders are very used to Easter moving every single year. The fact that it [could] be a moving date [would] not be too much of a problem,” Action Station’s director Laura O’Connell Rapira said.
Based on the cycle of the lunar calendar, the public holiday could move on a three-year rotation.
Dr Rangi Matamua, a Maori astronomy professor at the University of Waikato, highlighted the middle of June, late June and the middle of July as an ideal cycle. “[It could] shift up and down the calendar system generally over a three-year period.” There’s no annual date range for Matariki, but the celebration period usually spans seven or eight days in winter depending on the lunar cycle, Matamua explained.
Hikuroa, who is also the culture commissioner for the New Zealand National Commission for UNESCO has previously spoken to Stuff about the difficulty in choosing just one day. However, Hikuroa was certain it made sense to “Mondayise” the holiday, as was done with Waitangi Day and Anzac Day through an amendment of the Holidays Act 2003.
This is what Labour is planning to do. Kelvin Davis, the party’s co-leader, said that he expects it to always be at the beginning or end of a weekend. Friday has been the chosen day for Ngati Kahungunu’s Matariki celebrations across the Hawke’s Bay region for the last two decades. Te Rangi Huata, Ngati Kahungunu events manager, has been one of the driving forces behind these events, and has helped iwi in Dunedin and Auckland expand their Matariki offerings over the years. He didn’t see the date as having a big impact on celebrations. “The public holiday is the exclamation mark of the celebration, but [it] doesn’t mean that the celebration is for that one day, the celebration can take part over a number of weeks.”
The markers for Matariki and Puanga [Rigel] – another star marking the Maori New Year – vary around the country. To accommodate tribal variations, a wider, more inclusive discussion is needed. Labour plans to work with Matariki experts to determine appropriate dates for the holiday, but more voices may be needed. “[Discussion] needs to be at the community [level],” Hikuroa said.
While there may be some loud voices on the matter – both for and against – it will be pivotal to ensure all of them are heard. This could be done through public forums, community meetings and online submissions.
“Ultimately it will be a decision that government has to make, but in an ideal democracy it will be a decision New Zealanders have made,” Hikuroa said. He suggested Maori groups initiate the conversation and lay out an appropriate timeframe – or at least be given the opportunity to do so – before a larger group helps choose the specific date.
Matamua raised the idea of a committee made up of Maori astronomers and experts in the field to lead this discussion. “That’s not a call that any individual can make … it will need to be [in] consultation,” he said.
Ngati Kahungunu’s Huata thought it would be great if his iwi was involved in the process as they have been celebrating the season for 21 years. However, they won’t “spit the dummy”, he laughed. “If the dates work out for us, fantastic. If it doesn’t, well it will be great for the whole country to join in. We’re supportive whether we’re involved or not."
In terms of timing, Labour is aiming for 2022 to mark the first Matariki holiday. This allows time for businesses to financially recover from the effects of Covid-19.
Matamua would like to see conversations start now for what he described as a wonderful, fantastic and challenging task. “[There] needs to be a certain amount of groundwork put in place for this to be accepted as widely as possible and to be rolled out in the correct way. You’re asking, really, to inform 5 million people because it’s going to affect 5 million people, and so that information will need to go out as soon as possible.”
See Brittney Deguara's original article at
https://www.stuff.co.nz/pou-tiaki/122697737/theres-no-single-day-for-matariki--so-how-do-we-pick-a-new-holiday-date
7. Wairarapa Dark Sky Reserve the World's Biggest?
Warmer-hued street lighting and restrictions on sports field lights are part of a plan to make Wairarapa the world’s biggest dark sky reserve.
The region’s councils are proposing a change to the Wairarapa Combined District Plan which will enhance night sky viewing. The plan change would require new lighting to be low-Kelvin (warmer hue), to be shielded to direct light downwards and the proposal also included a 10pm curfew for sports ground lighting.
The Dark Sky Management Area, as it has been termed, includes the South Wairarapa and Carterton districts. South Wairarapa District Council has just approved the plan change to go out to public consultation.
The Wairarapa Dark Sky Society was preparing an application to the International Dark Sky Association for the region to be certified as an International Dark Sky Reserve. Becky Bateman of the society said the plan changes were vital for the application which they were hoping to submit by the end of the year. If approved, the reserve could be officially recognised as early as February 2021.
Bateman said there had been some confusion as to what proposed changes would mean, and she wanted to assure the community that it wouldn’t disrupt normal activities. “There are a lot of misconceptions that everyone has to have their lights turned off by 10 o’clock – that’s not true. “Of course you can still play netball at dark, as long as the lights are turned off when you’re not using them.
Lights that were on would need to be shielded down and also warmer colour hues were preferred (lower than 3000 Kelvin). “Rather than having blue and white lights, where a lot of councils are heading, think about more orangey-yellow that are a better colour for keeping the skies dark,” Bateman said. It was planned that Masterton district to the north would join the reserve in the next few years, which would then make it the largest in the world, Bateman said.
South Wairarapa Mayor Alex Beijen said a dark sky reserve would be a major attraction. “The South Wairarapa region is already well established on the tourist map, most notably for its world-renowned wineries. “Being a dark sky reserve, we would attract visitors all year round, giving rise to new businesses and jobs,” Beijen said. He said the council had already switched most of its street lighting from 4000K to 3000K LED bulbs and NZTA were yet to make the switch with most of its lighting on the state highways. The South Wairarapa dark sky reserve project received $100,000 in Provincial Growth Fund money last year to help progress its application.
Carterton District Council unanimously approved the plan change. The proposal will go out to public consultation later this month, where people can make submissions.
-- Updated from Piers Fuller's original article at
https://www.stuff.co.nz/national/122668025/plan-to-make-wairarapa-the-largest-dark-sky-reserve-in-the-world?
The link was forwarded by Kyra Xavia.
8. Moon Effects on Life?
Steve Butler recommends Jim Mora's interview with Jo Marchant on the Moon's influences on Earth's life.
Radio NZ's website summarises: The idea that the lunar cycle can influence our behaviour and wellbeing dates back thousands of years, but has been largely dismissed by modern medicine. However, new research suggests there may be some truth to these ancient theories. In her new book, The Human Cosmos, science writer Jo Marchant re-examines the effects that the moon may be having on us.
The 30-minute interview can be downloaded from https://www.rnz.co.nz/national/programmes/sunday/audio/2018763799/the-strange-effects-the-moon-could-be-having-on-our-health
9. Life on Venus?
An international team of astronomers, led by Professor Jane Greaves of Cardiff University, have announced the discovery of a rare molecule -- phosphine -- in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.
Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes -- floating free of the scorching surface, but still needing to tolerate very high acidity. The detection of phosphine molecules, which consist of hydrogen and phosphorus, could point to this extra-terrestrial ‘aerial’ life. The new discovery is described in a paper in Nature Astronomy.
The team first used the James Clerk Maxwell Telescope (JCMT) in Hawaii to detect the phosphine, and were then awarded time to follow up their discovery with 45 telescopes of the Atacama Large Millimeter/ submillimeter Array (ALMA) in Chile. Both facilities observed Venus at a wavelength of about 1 millimetre, much longer than the human eye can see -- only telescopes at high altitude can detect this wavelength effectively.
Professor Greaves says, “This was an experiment made out of pure curiosity, really -- taking advantage of JCMT’s powerful technology, and thinking about future instruments. I thought we’d just be able to rule out extreme scenarios, like the clouds being stuffed full of organisms. When we got the first hints of phosphine in Venus’ spectrum, it was a shock!”
Naturally cautious about the initial findings, Greaves and her team were delighted to get three hours of time with the more sensitive ALMA observatory. Bad weather added a frustrating delay, but after six months of data processing, the discovery was confirmed.
Team member Dr Anita Richards, of the UK ALMA Regional Centre and the University of Manchester, adds: “To our great relief, the conditions were good at ALMA for follow-up observations while Venus was at a suitable angle to Earth. Processing the data was tricky, though, as ALMA isn’t usually looking for very subtle effects in very bright objects like Venus.” Greaves adds: “In the end, we found that both observatories had seen the same thing -- faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below.”
Professor Hideo Sagawa of Kyoto Sangyo University then used his models for the Venusian atmosphere to interpret the data, finding that phosphine is present but scarce -- only about twenty molecules in every billion.
The astronomers then ran calculations to see if the phosphine could come from natural processes on Venus. They caution that some information is lacking -- in fact, the only other study of phosphorus on Venus came from one lander experiment, carried by the Soviet Vega 2 mission in 1985.
Massachusetts Institute of Technology scientist Dr William Bains led the work on assessing natural ways to make phosphine. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. Natural sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.
To create the observed quantity of phosphine on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to calculations by Dr Paul Rimmer of Cambridge University. Any microbes on Venus will likely be very different to their Earth cousins though, to survive in hyper-acidic conditions.
Earth bacteria can absorb phosphate minerals, add hydrogen, and ultimately expel phosphine gas. It costs them energy to do this, so why they do it is not clear. The phosphine could be just a waste product, but other scientists have suggested purposes like warding off rival bacteria.
Another MIT team-member, Dr Clara Sousa Silva, was also thinking about searching for phosphine as a ‘biosignature’ gas of non-oxygen-using life on planets around other stars, because normal chemistry makes so little of it. She comments: “Finding phosphine on Venus was an unexpected bonus! The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment -- but the clouds of Venus are almost entirely made of acid.”
Other possible biosignatures in the solar system may exist, like methane on Mars and water venting from the icy moons Europa and Enceladus. On Venus, it has been suggested that dark streaks where ultraviolet light is absorbed could come from colonies of microbes. The Akatsuki spacecraft, launched by the Japanese space agency JAXA, is currently mapping these dark streaks to understand more about this “unknown ultraviolet absorber.”
The team believes their discovery is significant because they can rule out many alternative ways to make phosphine, but they acknowledge that confirming the presence of “life” needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees centigrade, they are incredibly acidic -- around 90% sulphuric acid -- posing major issues for microbes to survive there. Professor Sara Seager and Dr Janusz Petkowski, also both at MIT, are investigating how microbes could shield themselves inside droplets.
The team are now eagerly awaiting more telescope time, for example to establish whether the phosphine is in a relatively temperate part of the clouds, and to look for other gases associated with life. New space missions could also travel to our neighbouring planet, and sample the clouds in situ to further search for signs of life.
-- From a press release by the UK Royal Astronomical Society, forwarded by Karen Pollard. See the original with graphics at
https://ras.ac.uk/news-and-press/news/hints-life-venus
See also Jonathan Amos's article at
https://www.bbc.com/news/science-environment-54133538
The Nature Astronomy paper is at
https://www.nature.com/articles/s41550-020-1174-4
10. Dark Matter Problem?
Observations by the NASA/ESA Hubble Space Telescope and the European Southern Observatory's Very Large Telescope (VLT) in Chile have found that something may be missing from the theories of how dark matter behaves. This missing ingredient may explain why researchers have uncovered an unexpected discrepancy between observations of the dark matter concentrations in a sample of massive galaxy clusters and theoretical computer simulations of how dark matter should be distributed in clusters. The new findings indicate that some small-scale concentrations of dark matter produce lensing effects that are 10 times stronger than expected.
Dark matter is the invisible glue that keeps stars, dust, and gas together in a galaxy. This mysterious substance makes up the bulk of a galaxy's mass and forms the foundation of our Universe's large-scale structure. Because dark matter does not emit, absorb, or reflect light, its presence is only known through its gravitational pull on visible matter in space. Astronomers and physicists are still trying to pin down what it is.
Galaxy clusters, the most massive and recently assembled structures in the Universe, are also the largest repositories of dark matter. Clusters are composed of individual member galaxies that are held together largely by the gravity of dark matter. "Galaxy clusters are ideal laboratories in which to study whether the numerical simulations of the Universe that are currently available reproduce well what we can infer from gravitational lensing," said Massimo Meneghetti of the INAF-Observatory of Astrophysics and Space Science of Bologna in Italy, the study's lead author. "We have done a lot of testing of the data in this study, and we are sure that this mismatch indicates that some physical ingredient is missing either from the simulations or from our understanding of the nature of dark matter", added Meneghetti.
"There's a feature of the real Universe that we are simply not capturing in our current theoretical models," added Priyamvada Natarajan of Yale University in Connecticut, USA, one of the senior theorists on the team. "This could signal a gap in our current understanding of the nature of dark matter and its properties, as these exquisite data have permitted us to probe the detailed distribution of dark matter on the smallest scales."
The distribution of dark matter in clusters is mapped by measuring the bending of light - the gravitational lensing effect - that they produce. The gravity of dark matter concentrated in clusters magnifies and warps light from distant background objects. This effect produces distortions in the shapes of background galaxies which appear in images of the clusters. Gravitational lensing can often also produce multiple images of the same distant galaxy.
The higher the concentration of dark matter in a cluster, the more dramatic its light-bending effect. The presence of smaller-scale clumps of dark matter associated with individual cluster galaxies enhances the level of distortions. In some sense, the galaxy cluster acts as a large-scale lens that has many smaller lenses embedded within it.
Hubble's crisp images were taken by the telescope's Wide Field Camera 3 and Advanced Camera for Surveys. Coupled with spectra from the European Southern Observatory's Very Large Telescope (VLT), the team produced an accurate, high-fidelity, dark-matter map. By measuring the lensing distortions astronomers could trace out the amount and distribution of dark matter. The three key galaxy clusters, MACS J1206.2-0847, MACS J0416.1-2403, and Abell S1063, were part of two Hubble surveys: The Frontier Fields and the Cluster Lensing and Supernova survey with Hubble (CLASH) programs.
The Hubble images showed the usual dramatic arcs and elongated images of distant galaxies produced by each cluster's gravitational lensing.
But, to the team's surprise, they also revealed an unexpected number of smaller-scale arcs and distorted images nested near each cluster's core, where the most massive galaxies reside. The researchers believe the nested lenses are produced by the gravity of dense concentrations of matter inside the individual cluster galaxies. Follow-up spectroscopic observations measured the velocity of the stars orbiting inside several of the cluster galaxies to thereby pin down their masses.
"The data from Hubble and the VLT provided excellent synergy," said team member Piero Rosati of the Università degli Studi di Ferrara in Italy, who led the spectroscopic campaign. "We were able to associate the galaxies with each cluster and estimate their distances." "The speed of the stars gave us an estimate of each individual galaxy's mass, including the amount of dark matter," added team member Pietro Bergamini of the INAF-Observatory of Astrophysics and Space Science in Bologna, Italy.
By combining Hubble imaging and VLT spectroscopy, the astronomers were able to identify dozens of multiply imaged, lensed, background galaxies. This allowed them to assemble a well-calibrated, high-resolution map of the mass distribution of dark matter in each cluster. The team then compared the dark-matter maps with samples of simulated galaxy clusters with similar masses, located at roughly the same distances. The clusters in the computer model did not show any of the same level of dark-matter concentration on the smallest scales - the scales associated with individual cluster galaxies.
"The results of these analyses further demonstrate how observations and numerical simulations go hand in hand", said team member Elena Rasia of the INAF-Astronomical Observatory of Trieste, Italy. "With advanced cosmological simulations, we can match the quality of observations analysed in our paper, permitting detailed comparisons like never before," added Stefano Borgani of the Università degli Studi di Trieste, Italy.
Astronomers, including those of this team, look forward to continuing to probe dark matter and its mysteries in order to finally pin down its nature.
The team's paper appeared in the 11 September 2020 issue of the journal Science.
The original press release was forwarded by Karen Pollard. See it at
https://www.spacetelescope.org/news/heic2016/
11. Covid Quotes
"I never thought the comment 'I wouldn't touch him/her with a six-foot pole' would become a national policy, but here we are."
"At the store there was a big X by the register for me to stand on… I've seen too many Road Runner cartoons to fall for that one."
"They said a mask and gloves were enough to go to the grocery store. They lied, everybody else had clothes on."
Alan Gilmore Phone: 03 680 6817
P.O. Box 57 alan.gilmore@canterbury.ac.nz
Lake Tekapo 7945
New Zealand
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June Celestial Calendar by Dave Mitsky
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Minor Planet Occultation Updates:
This email describes updates for minor planet occultations for September 2020.
If you do not wish to receive these updates please advise
the Occultation Section.
You can view updated paths and other details at:
http://www.occultations.org.nz/
Minor Planet Occultation Updates:
================================
Events of particular ease or importance below are marked: *****
***Sep 2 (550) SENTA: Star Mag 9.5, Max dur 7.3 sec, Mag Drop 2.33
A narrow path across Australia from Brisbane across south-eastern Queensland, north-western New South Wales and south-eastern South Australia to near Ceduna.
Details: http://www.occultations.org.nz//planet/2020/updates/200902_550_67262_u.htm
Sep 2 (934) THURINGIA: Star Mag 12.11, Max dur 8.5 sec, Mag Drop 2.64
A narrow path across the South Island of New Zealand crossing Blenheim and Nelson.
Details: http://www.occultations.org.nz//planet/2020/updates/200902_934_65884_u.htm
Sep 2 (117) LOMIA: Star Mag 11.9, Max dur 12 sec, Mag Drop 1.79
A fairly broad path across Australia from Port Lincoln across eastern South Australia and Queensland to Ingham.
Details: http://www.occultations.org.nz//planet/2020/updates/200902_117_65886_u.htm
Sep 3 (39) LAETITIA: Star Mag 11.52, Max dur 6.4 sec, Mag Drop 0.62
Across northern Australia from Darwin across northern Northern Territory and Weipa in northern Queensland (in morning twilight).
Details: http://www.occultations.org.nz//planet/2020/updates/200903_39_65892_u.htm
Sep 3 (79) EURYNOME: Star Mag 11.47, Max dur 3.3 sec, Mag Drop 0.93
Across Australia from near Geraldton across central Western Australia, southern Northern Territory and central Queensland to Mackay just into morning twilight.
Details: http://www.occultations.org.nz//planet/2020/updates/200903_79_65890_u.htm
Sep 3 (914) PALISANA: Star Mag 10.6, Max dur 4 sec, Mag Drop 3.47
Across south-eastern Australia from the vicinity of Coffs Harbour across northern New South Wales and south-eastern South Australia at low and decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200903_914_73082_u.htm
Sep 4 (19) FORTUNA: Star Mag 12.48, Max dur 25.7 sec, Mag Drop 0.07
A fairly broad path across south-eastern Australia, mostly covering Bass Straight, but grazing the south-eastern Victorian and northern Tasmanian coasts.
Details: http://www.occultations.org.nz//planet/2020/updates/200904_19_65906_u.htm
Sep 5 (747) WINCHESTER: Star Mag 12.06, Max dur 17.4 sec, Mag Drop 0.32
Across the North Island of New Zealand, crossing the north-eastern corner at Hicks Bay, possibly extending to Opotki and Gisborne .
Details: http://www.occultations.org.nz//planet/2020/updates/200905_747_65920_u.htm
***Sep 6 (1977) SHURA: Star Mag 9.2, Max dur 0.9 sec, Mag Drop 7.44
Along a narrow path across western and northern Australia from just north of Perth across Western Australia, central Northern Territory an d into northern Queensland near Cooktown at decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200906_1977_65926_u.htm
Sep 7 (134) SOPHROSYNE: Star Mag 11.5, Max dur 10.4 sec, Mag Drop 2.3
Across Australia from Ceduna across eastern South Australia and into Queensland at low and decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200907_134_73092_u.htm
Sep 9 (981) MARTINA: Star Mag 11.4, Max dur 3.6 sec, Mag Drop 3.97
A narrow path across Australia from Kalbarri across central Queensland, southern Northern Territory and northern Queensland to Townsville.
Details: http://www.occultations.org.nz//planet/2020/updates/200909_981_73094_u.htm
Sep 9 (5505) RUNDETAARN: Star Mag 7.7, Max dur 2.9 sec, Mag Drop 8.02
Along a narrow path across northern Australia from Wyndham across northern Northern Territory and northern Queensland to Mackay.
Details: http://www.occultations.org.nz//planet/2020/updates/200909_5505_67042_u.htm
Sep 10 (218) BIANCA: Star Mag 10.97, Max dur 7.8 sec, Mag Drop 2.6
Across Western Australia from Derby to a little north of Perth.
Details: http://www.occultations.org.nz//planet/2020/updates/200910_218_65952_u.htm
Sep 10 (203) POMPEJA: Star Mag 12.46, Max dur 5.9 sec, Mag Drop 1.68
Across Australia from Eucla across central South Australia and central Queensland to Rockhampton.
Details: http://www.occultations.org.nz//planet/2020/updates/200910_203_65954_u.htm
Sep 11 (2241) ALCATHOUS: Star Mag 10.98, Max dur 3.7 sec, Mag Drop 5.4
Across western Australia from Geraldton across central Western Australia and into central Northern Territory at decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200911_2241_65958_u.htm
Sep 12 (322) PHAEO: Star Mag 11.9, Max dur 4.5 sec, Mag Drop 2.25
Across Australia from Central Australia in evening twilight across central Queensland to near Rockhampton.
Details: http://www.occultations.org.nz//planet/2020/updates/200912_322_65964_u.htm
***Sep 12 (921) JOVITA: Star Mag 9.4, Max dur 2 sec, Mag Drop 5.94
Across south-eastern Australia from Victor Harbour across south-eastern South Australia, central Victoria and (just) south-eastern New South Wales near Eden, and across the North Island of New Zealand near Auckland.
Details: http://www.occultations.org.nz//planet/2020/updates/200912_921_67272_u.htm
Sep 13 (136) AUSTRIA: Star Mag 12.44, Max dur 6.4 sec, Mag Drop 1.07
A narrow path across Australia, from Dampier across central Western Australia to east of Esperance.
Details: http://www.occultations.org.nz//planet/2020/updates/200913_136_65980_u.htm
Sep 13 (992) SWASEY: Star Mag 9.5, Max dur 0.9 sec, Mag Drop 6.82
A narrow path across Australia from northern South Australia in evening twilight along the Queensland New South Wales border to Byron Bay.
Details: http://www.occultations.org.nz//planet/2020/updates/200913_992_73106_u.htm
***Sep 13 (337) DEVOSA: Star Mag 10.19, Max dur 8 sec, Mag Drop 3.41
Across eastern Australia from Gympie across south-eastern Queensland, inland eastern New South Wales and central Victoria to western Melbourne, Geelong and Cape Otway.
Details: http://www.occultations.org.nz//planet/2020/updates/200913_337_65976_u.htm
Sep 13 (225) HENRIETTA: Star Mag 10.22, Max dur 8.6 sec, Mag Drop 1.3
Across Australia from Townsville across Queensland and north-eastern to western South Australia.
Details: http://www.occultations.org.nz//planet/2020/updates/200913_225_65978_u.htm
*****Sep 14 (373) MELUSINA: Star Mag 6.94, Max dur 10.3 sec, Mag Drop 7.14
A path across Australia from near Adelaide across eastern South Australia and western Queensland to Karumba and Weipa.
Details: http://www.occultations.org.nz//planet/2020/updates/200914_373_65986_u.htm
Sep 14 (56) MELETE: Star Mag 10.9, Max dur 8.2 sec, Mag Drop 1.34
Across south-western Australia from Busselton along the southern coast of Western Australia, and across central South Australia at decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200914_56_73108_u.htm
Sep 15 (136) AUSTRIA: Star Mag 11.5, Max dur 6 sec, Mag Drop 1.78
Across western Australia, from near Kalbarri across southern Western Australia and into central South Australia and western New South Wales at decreasing elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200915_136_73110_u.htm
Sep 17 (39) LAETITIA: Star Mag 12.23, Max dur 8.1 sec, Mag Drop 0.34
A fairly broad path across the North Island of New Zealand, Directly over Lake Taupo and including most of the central North Island, possibly to Auckland.
Details: http://www.occultations.org.nz//planet/2020/updates/200917_39_66016_u.htm
Sep 17 (514) ARMIDA: Star Mag 12.03, Max dur 9.7 sec, Mag Drop 1.55
Across Australia from Mossman across northern Queensland, central Northern Territory and central Western Australia to near Geraldton.
Details: http://www.occultations.org.nz//planet/2020/updates/200917_514_66014_u.htm
Sep 17 (41) DAPHNE: Star Mag 12.5, Max dur 7.8 sec, Mag Drop 1.21
A broad path across south-western Western Australia, from Bunbury (possibly including Perth) to Albany (and possibly Esperence), and across the south-western half of Tasmania in morning twilight (just before dawn).
Details: http://www.occultations.org.nz//planet/2020/updates/200917_41_66026_u.htm
Sep 17 (13) EGERIA: Star Mag 10.48, Max dur 10.1 sec, Mag Drop 1.46
A broad path across Australia from Townsville across northern and western Queensland and central South Australia.
Details: http://www.occultations.org.nz//planet/2020/updates/200917_13_66020_u.htm
Sep 18 (488) KREUSA: Star Mag 10.64, Max dur 7.6 sec, Mag Drop 3.37
A fairly broad path across Australia from Carnarvon across central Western Australia, central Northern Territory and northern Queensland to Innisfail.
Details: http://www.occultations.org.nz//planet/2020/updates/200918_488_66032_u.htm
Sep 19 (521) BRIXIA: Star Mag 11.57, Max dur 9.8 sec, Mag Drop 2.55
Across Australia from just south of Carnarvon across central Western Australia, southern Northern Territory and central Queensland to Mackay.
Details: http://www.occultations.org.nz//planet/2020/updates/200919_521_66036_u.htm
Sep 21 (48) DORIS: Star Mag 11.8, Max dur 6.3 sec, Mag Drop 1.69
A broad path across southern Australia from Bussleton in evening twilight, along the southern Western Australia coast including Esperence, then across southern South Australia just north of Port Augusta and into western New South Wales at very low elevation.
Details: http://www.occultations.org.nz//planet/2020/updates/200921_48_73124_u.htm
Sep 22 (490) VERITAS: Star Mag 12.18, Max dur 9.2 sec, Mag Drop 1.92
Across Australia from Derby across northern Western Australia (in evening twilight), across central Northern Territory and central Queensland to Bundaberg.
Details: http://www.occultations.org.nz//planet/2020/updates/200922_490_66062_u.htm
Sep 23 (117) LOMIA: Star Mag 12.03, Max dur 7.7 sec, Mag Drop 1.86
A broad path along most of the west coast of both islands of New Zealand, possibly including Auckland.
Details: http://www.occultations.org.nz//planet/2020/updates/200923_117_66072_u.htm
Sep 24 (191) KOLGA: Star Mag 11.46, Max dur 5.1 sec, Mag Drop 3.26
Across north-eastern Australia in evening twilight, from northern Northern Territory just on sunset to Bowen near the end of twilight.
Details: http://www.occultations.org.nz//planet/2020/updates/200924_191_66084_u.htm
Sep 24 (62) ERATO: Star Mag 11.8, Max dur 8.3 sec, Mag Drop 0.98
Across Australia from Proserpine across Queensland, north-western South Australia and southern Western Australia to Esperance and Albany.
Details: http://www.occultations.org.nz//planet/2020/updates/200924_62_66086_u.htm
Sep 26 (41) DAPHNE: Star Mag 11.9, Max dur 9 sec, Mag Drop 1.59
A broad path across New Zealand, including most of the South Island north of about Haast and Dunedin, and the North Island south of about Bulls, including Wellington and Christchurch.
Details: http://www.occultations.org.nz//planet/2020/updates/200926_41_66104_u.htm
Sep 27 (1015) CHRISTA: Star Mag 11.86, Max dur 4.7 sec, Mag Drop 2.93
Across central New Zealand, including the North Island south of about Napier and Opunake, and the South Island north of about Kaikura and Greymouth.
Details: http://www.occultations.org.nz//planet/2020/updates/200927_1015_66116_u.htm
Sep 27 (415) PALATIA: Star Mag 12.5, Max dur 11.4 sec, Mag Drop 0.86
Across south-eastern Australia from near Nowra across south-eastern New South Wales, north-eastern and central southern Victoria to Melbourne and Geelong.
Details: http://www.occultations.org.nz//planet/2020/updates/200927_415_66114_u.htm
Sep 28 (2094) MAGNITKA: Star Mag 6.9, Max dur 1 sec, Mag Drop 9.73
Along a very narrow path across Australia from near Geraldton across Western Australia, southern Northern Territory and Queensland to Townsville.
Details: http://www.occultations.org.nz//planet/2020/updates/200928_2094_73140_u.htm
Sep 28 (618) ELFRIEDE: Star Mag 11.27, Max dur 14.9 sec, Mag Drop 2.1
Across New Zealand, including the eastern halves of both islands, from Hicks bay to Invercargill, and including Wellington and Christchurch.
Details: http://www.occultations.org.nz//planet/2020/updates/200928_618_66126_u.htm
Sep 29 (336) LACADIERA: Star Mag 11.96, Max dur 6.9 sec, Mag Drop 1.82
Across south-eastern Australia in evening twilight, from Kingston SE in south-eastern South Australia across Victoria including Melbourne to Mallacoota, and across the North Island of New Zealand near Auckland.
Details: http://www.occultations.org.nz//planet/2020/updates/200929_336_66136_u.htm
Sep 29 (424) GRATIA: Star Mag 13.48, Max dur 9.4 sec, Mag Drop 0.65
Across northern Australia, crossing Darwin and Cape York.
Details: http://www.occultations.org.nz//planet/2020/updates/200929_424_73482_u.htm
Sep 29 (892) SEELIGERIA: Star Mag 12.46, Max dur 3.5 sec, Mag Drop 2.9
Across Australia from Carnarvon across Western Australia and coastal South Australia, including Adelaide, across mid western to south-eastern Victoria including Melbourne, and across north-eastern Tasmania.
Details: http://www.occultations.org.nz//planet/2020/updates/200929_892_66140_u.htm
Sep 29 (22) KALLIOPE: Star Mag 8.7, Max dur 16.4 sec, Mag Drop 2.13
A broad path across northern Australia from Mossman (including Cairns to Cooktown) across northern Queensland, central Northern Territory and northern Western Australia to Broome.
Details: http://www.occultations.org.nz//planet/2020/updates/200929_22_67290_u.htm
Sep 30 (373) MELUSINA: Star Mag 12.01, Max dur 11.4 sec, Mag Drop 2.01
Across Western Australia from Broome to Esperance.
Details: http://www.occultations.org.nz//planet/2020/updates/200930_373_66148_u.htm
Note: for some events there will be an additional last minute update so check
for one, if you can, on the day of the event or in the days leading up to it.
You may need to click "Reload" or "Refresh" in your browser to see the updated
page.
Please report all attempts at observation to Director Occsec at the address
below. (PLEASE report observations on a copy of the report available from our
website).
John Sunderland
---------------------------------------------
RASNZ Occultation Section
P.O.Box 3181 / Wellington, 6140 / New Zealand
---------------------------------------------
WEBSITE: http://www.occultations.org.nz/
Email: Director@occultations.org.nz
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Further links and discussion can be found at the groups/links below
Astronomy in New Zealand - Groups.io
https://groups.io/g/AstronomyNZ
Astronomy in New Zealand - Facebook
https://www.facebook.com/groups/5889909863/
Google Group
https://groups.google.com/g/nzastrochat
Astronomy in Wellington
https://www.facebook.com/groups/11451597655/
Blogger Posts
http://laintal.blogspot.com/
Twitter
https://twitter.com/Laintal
Groups.io
Astronomy in New Zealand
https://groups.io/g/AstronomyNZ
AstronomyNZ@groups.io
Wellington Astronomers
https://groups.io/g/WellingtonAstronomers
WellingtonAstronomers@groups.io
AucklandAstronomers
https://groups.io/g/AucklandAstronomers
AucklandAstronomers@groups.io
North Island Astronomers
https://groups.io/g/NorthIslandAstronomers
NorthIslandAstronomers@groups.io
South Island Astronomers
https://groups.io/g/SouthIslandAstronomers
SouthIslandAstronomers@groups.io
NZAstrochat
https://groups.io/g/NZAstrochat
NZAstrochat@groups.io
NZ Photographers And Observers
https://groups.io/g/NZPhotographers
NZPhotographers@groups.io
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Please note:
My standard caveat that these are the views of a learned amateur, not a professional in the sector, applies as always.
The above post/email/update represents my own words, views, research and opinions, unless stated otherwise the above work
represents my own writing. I’ll give credit or thanks if I have used or represented other people’s words and/or opinions.
The links and references listed below represent the work and research of the respective author’s.
Questions and constructive criticism are always welcome, however I don’t believe anything written here by myself is any reason for impolite behaviour.
Thanks for your time and I hope you have enjoyed reading.
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