August 2021 News and research items
Hi everyone
Please find this month’s news and research links attached, and what an interesting month this one has been.
Today an interesting paper looking at Ceres arrived in the inbox and Ceres could hold a briny layer of salty water beneath its crust. The icy satellites of Jupiter get a good look in too with a look at the exospheres of Ganymede and Callisto, and the Icy geology of Europa. Moving into the inner solar system there is a look at a Mercury lander, amazing as it is a rover to the polar regions would have been my preference.
There is another look at planets around Red dwarf stars perhaps the flares are directed at the polar regions sparing any orbiting planets from there effects, so there is a lot of reading to catch up on there.
Closer to Earth another look at Starlink and the impacts of Mega constellations keeps popping up.
Here in New Zealand were into day 9 of a Level 4 Covid lockdown, so you will have plenty of time to catch up on all the links and papers that interest you for your lockdown reading. As always it’s great catching up with my international friends and not just on Science too. The look at nodes of persisting complexity is a very good read and suggest New Zealand is one of the best places to be.
Research_News_20_08_2021
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/
Reddit
https://www.reddit.com/user/Edwin_Rod_NZ
Quaroa
https://www.quora.com/q/astronomyinnewzealand
Twitter
https://twitter.com/EdwinRodham
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Research papers
Replenishment of Near-Surface Water Ice by Impacts Into Ceres' Volatile-Rich Crust
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL094223
A tenuous, collisional atmosphere on Callisto
https://arxiv.org/abs/2107.12341
Evidence for a sublimated water atmosphere on Ganymede from Hubble Space Telescope observations
https://arxiv.org/abs/2106.03570
Uplifts and Small Chaos Features on Europa
https://arxiv.org/abs/2108.01795
Mercury Lander
https://arxiv.org/abs/2107.06795
Low Levels of Sulphur Dioxide Contamination of Phosphine Spectra from Venus
https://arxiv.org/abs/2108.08393
Science Goals and Objectives for the Dragonfly Titan Rotorcraft Relocatable Lander
https://iopscience.iop.org/article/10.3847/PSJ/abfdcf
Planet formation in stellar binaries
https://arxiv.org/abs/2107.11389
Transmission Spectra of Tidally Locked Habitable Planets
https://arxiv.org/abs/2107.14603
Giant flares on fully convective stars occur at high latitudes
https://arxiv.org/abs/2108.01917
Habitability Models for Astrobiology
https://arxiv.org/abs/2108.05417
TESS observations of flares
https://arxiv.org/abs/2108.10670
Habitability and Biosignatures of Hycean Worlds
https://arxiv.org/abs/2108.10888
Dark Primitive Asteroids Account for a Large Share of KPg Scale Impacts on the Earth
https://arxiv.org/abs/2107.03458
A Report to ESO Council on the Impact of Satellite Constellations
https://arxiv.org/abs/2108.03999
New Features of Parenago’s Discontinuity from Gaia DR1 Data
https://www.researchgate.net/publication/328359737_New_Features_of_Parenago's_Discontinuity_from_Gaia_DR1_Data/link/5bd21bf5299bf1124fa368b9/download
Warm terrestrial planet with half the mass of Venus transiting a nearby star
https://arxiv.org/abs/2108.03323
Belatedly Habitable Planets
https://iopscience.iop.org/article/10.3847/2515-5172/ac1ea2
Leveraging Models to Constrain the Climates of Rocky Exoplanets
https://arxiv.org/abs/2108.08386
Reduced Nitrogen-Rich Super-Earth Atmospheres
https://arxiv.org/abs/2107.13097
Starting Life and Searching for Life on Rocky Planets
https://arxiv.org/abs/2108.08388
An Analysis of the Potential for the Formation of ‘Nodes of Persisting Complexity’
https://www.mdpi.com/2071-1050/13/15/8161/htm
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Interesting News items
Zeroing In On the Source Of The Impactor That Wiped Out The Dinosaurs
http://astrobiology.com/2021/07/zeroing-in-on-the-source-of-the-impactor-that-wiped-out-the-dinosaurs.html
An interesting look at water in the Moons Exosphere
NASA Study Highlights Importance of Surface Shadows in Moon Water Puzzle
https://www.jpl.nasa.gov/news/nasa-study-highlights-importance-of-surface-shadows-in-moon-water-puzzle
Sounds of the stars
https://www.nasa.gov/feature/goddard/2021/nasa-s-tess-tunes-into-an-all-sky-symphony-of-red-giant-stars
Sublimation Producing Water Vapor on Ganymede
https://www.centauri-dreams.org/2021/07/29/sublimation-producing-water-vapor-on-ganymede/
the Volcanos here sure are interesting and active
http://spaceref.com/venus/new-evidence-of-recent-geologically-speaking-venusian-volcanism.html
Rocket Lab
https://www.stuff.co.nz/science/126001666/rocket-lab-launching-satellite-to-the-moon-to-test-path-for-nasas-future-missions
A detailed look here at my favourite stars
Can M-Dwarf Planets Survive Stellar Flares?
https://www.centauri-dreams.org/2021/08/10/can-m-dwarf-planets-survive-stellar-flares/
Habitability: Similar Magnetic Activity Links Stellar Types
https://www.centauri-dreams.org/2021/08/12/habitability-similar-magnetic-activity-links-stellar-types/
Giant white-light flares on fully convective stars occur at high latitudes
https://arxiv.org/abs/2108.01917
L 98-59 b: A Rocky World with Half the Mass of Venus
https://www.centauri-dreams.org/2021/08/06/l-98-59-b-a-rocky-world-with-half-the-mass-of-venus/
A Landing Site for Dragonfly
https://www.centauri-dreams.org/2021/08/17/a-landing-site-for-dragonfly/
A neighbouring planetary system reveals its secrets
https://www.eso.org/public/videos/eso2112a/
New ESO observations show rocky exoplanet has just half the mass of Venus
https://www.eso.org/public/news/eso2112/
Interesting reading here, It looks like NZ is the place to be especially after 2040 it seems.
New Zealand named best country to survive a global collapse
https://www.nzherald.co.nz/nz/new-zealand-named-best-country-to-survive-a-global-collapse/HGERPOHJNXOWIPCZSUUJS67SNM/
The best place to ride out a global societal collapse is New Zealand, study finds
https://www.washingtonpost.com/world/2021/07/29/new-zealand-collapse/
An Analysis of the Potential for the Formation of ‘Nodes of Persisting Complexity’
https://www.mdpi.com/2071-1050/13/15/8161/htm
MIT Predicted in 1972 That Society Will Collapse This Century. New Research Shows We’re on Schedule
https://www.vice.com/en/article/z3xw3x/new-research-vindicates-1972-mit-prediction-that-society-will-collapse-soon
The Limits to Growth
https://www.clubofrome.org/publication/the-limits-to-growth
This is new to me - Very interesting I have another Paper to read
https://www.centauri-dreams.org/2021/08/20/how-to-explain-unusual-stellar-acceleration/
New Features of Parenago’s Discontinuity from Gaia DR1 Data
https://www.researchgate.net/publication/328359737_New_Features_of_Parenago's_Discontinuity_from_Gaia_DR1_Data/link/5bd21bf5299bf1124fa368b9/download
A detailed look here at my favorite stars
Hi Everyone
Two interesting papers here along with two interesting articles from Paul @ Centauri Dreams
I have always had an interest in small red dwarf stars and the possible exoplanets and life that might exist there and Over the last few years have found myself spending more time at Centaur Dreams as Paul looks at the subject in detail, Its also good to connect with fellow readers too.
It looks like there is plenty to read here
Can M-Dwarf Planets Survive Stellar Flares?
https://www.centauri-dreams.org/2021/08/10/can-m-dwarf-planets-survive-stellar-flares
Habitability: Similar Magnetic Activity Links Stellar Types
https://www.centauri-dreams.org/2021/08/12/habitability-similar-magnetic-activity-links-stellar-types/
Modeling Stellar Activity-rotation Relations in Unsaturated Cool Stars
https://iopscience.iop.org/article/10.3847/1538-4357/ac05c7
Giant white-light flares on fully convective stars occur at high latitudes
https://arxiv.org/abs/2108.01917
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Updates from Andrew B,
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RASNZ
Royal Astronomical Society of New Zealand
eNewsletter: No. 248, 20 August 2021
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. IAU Statement on Afghanistan
2. RASNZ Beanies
3. The Solar System in September
4. Beaumont Prize Writing Competition - Closes Sept. 1
5. New Zealand Astrophotography Competition - Closes Sept. 21
6. Variable Star News
7. Global Meteor Network
8. New Zealand Dark Sky Handbook
9. Galactic Fireworks: New Pictures of Nearby Galaxies
10. Centaurus A Imaged by Event Horizon Telescope
11. Mars Sampling Fails
12. James Webb Telescope to be Renamed?
13. Gifford-Eiby Lecture Fund
14. Kingdon-Tomlinson Fund
15. How to Join the RASNZ
16. Quote
1. IAU Statement on Afghanistan
Message from the IAU about the scientific community in Afghanistan
The International Astronomical Union (IAU) is profoundly concerned by the current events in Afghanistan and fears adverse consequences to its scientific community, most notably continued access for women in science and access to education for girls.
We have been receiving reports of the dire circumstances and numerous requests for help from our colleagues, who in this time of crisis fear for their lives for no other reason than that they are upholding scientific principles and furthering scientific knowledge. Their freedom, security and wellbeing are under threat.
The IAU's mission is to promote and safeguard the science of astronomy in all its aspects, including research, communication, education and development through international cooperation. Whereas the IAU does not wish to influence the political decisions of any country, it is concerned about the potential adverse consequences to its community. Triggered by the life-threatening situation in which our colleagues find themselves, the IAU wishes to encourage its members and National Members to publicly denounce any action that endangers or threatens their wellbeing and to pursue any protective action of our colleagues in need. The IAU also strongly encourages our National Members and other colleagues to help wherever possible in this difficult time for Afghanistan.
The IAU would like to strongly reaffirm its adherence to the ISCU Principle of Universality of Science [link below], which “requires freedom of movement, association, expression and communication for scientists […] and opposes discrimination based on such factors as ethnic origin, religion, citizenship, language, political or other opinion.”
For ISCU Principle of Universality of Science see https://council.science/wp-content/uploads/2017/04/Academic_freedom_ICSU_CFRS_principle_document.pdf
See the original IAU statement at https://www.iau.org/news/announcements/detail/ann21044/
2. RASNZ Beanies
Astronz advises that a limited stock of the RASNZ Centennial Beanies have arrive in and are now available on the Astronz website at
https://astronz.nz/products/rasnz-centenary-beanie .
3. The Solar System in September
Dates and times shown are NZST (UT + 12 hours) up to September 25. NZDT begins on Sunday 26, nominally at 2am NZST, when clocks should be moved forward 1 hour to 3am 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 southern SPRING EQUINOX is on September 23 with the Sun moving south across the equator at about 7.20am.
THE SUN and PLANETS in SEPTEMBER, Rise & Set Magnitude & Constellation
SEP 1 NZST SEP 30 NZDT
Mag Cons Rise Set Mag Cons Rise Set
SUN -26.7 Leo 6.43am 5.58pm -26.7 Vir 6.54am 7.27pm
Merc -0.1 Vir 7.36am 7.59pm 1.4 Vir 7.20am 9.03pm
Venus -4.0 Vir 8.16am 9.20pm -4.2 Lib 8.38am 11.22pm
Mars 1.8 Leo 7.18am 6.57pm 1.7 Vir 7.05am 7.38pm
Jupiter -2.9 Cap 4.35pm 6.26am -2.7 Cap 3.26pm 5.24am
Saturn 0.3 Cap 3.05pm 5.35am 0.5 Cap 2.05pm 4.38am
Uranus 5.7 Ari 11.19pm 9.33am 5.7 Ari 10.22pm 8.37am
Neptune 7.8 Aqr 6.51pm 7.29am 7.8 Aqr 5.53pm 6.33am
Pluto 14.5 Sgr 1.53pm 4.56am 14.5 Sgr 1.01pm 4.01am
SEP 1 NZST SEP 30 NZDT
TWILIGHTS morning evening morning evening
Civil: start 6.18am, end 6.24pm start 6.29am, end 7.53pm
Nautical: start 5.46am, end 6.56pm start 5.57am, end 8.26pm
Astro: start 5.14am, end 7.28pm start 5.23am, end 8.59pm
SEPTEMBER PHASES OF THE MOON, times NZST & UT (NZDT after Sep 26)
New Moon: Sep 7 at 12.52pm (00:52 UT)
First quarter: Set 14 at 8.40am (Sep 13,20:40 UT)
Full Moon: Sep 21 at 11.55am (Sep 20,23:55 UT)
Last quarter Sep 29 at 2.57pm (01:57 UT)
THE PLANETS in SEPTEMBER 2021
MERCURY is well placed for evening viewing during September. It is at its greatest easterly elongation from the Sun on September 14. Mercury then sets 2 hours and 20 minutes after the Sun. An hour after sunset it will be 16° up, almost due west. Mercury's magnitude will be 0.1.
On September 9, at ca 7pm, Mercury will be 6.6° to the left of a very thin crescent moon, on the 21st the planet will be just under 1.5° to the left of the first magnitude star, Spica and on the 27th Mercury is stationary and then starts retracing its path back towards Spica.
VENUS continues to move up in the western evening sky during September. It sets more than 4 hours after the Sun on the 30th, at 11.22pm (NZDT) for Wellington. At that stage it will be about 45° from the Sun.
On the 6th, Venus will be just over 1.5° to the right of Spica. Compare to Mercury on the 21st. On the 10th, the crescent moon will be just over 4° to the right of Venus. On the 18th, Venus moves into Libra.
MARS remains an evening object during September. Just. On the 1st the planet will be 10° up when the Sun sets at about 6pm. Mars itself then sets an hour later. On the 30th Mars sets only 11 minutes after the Sun. The two are then less than 3° apart. It won't be a good month for observing Mars.
JUPITER and SATURN are both in Capricornus at present. The moon passes them on successive nights during September. Saturn on the 17th and Jupiter on the 18th. In both instances the planets are just over 3.5° to the left of the moon as seen early evening.
Both planets set well after midnight, making them well placed for evening viewing.
URANUS and NEPTUNE
Uranus does not rise until late evening, so is best viewed as a morning object. Neptune, on the other hand, is at opposition on the 14th, so is at its brightest and in the sky all night.
The full moon is 3.5° from Neptune on the 20th with planet to the lower left of the moon. On the morning of the 25th, the moon, now a little past full, will be less than half a degree (the moon's apparent diameter) above Uranus at 5am, an hour before sunrise.
PLUTO rises early afternoon during September, so is very much an evening object although it doesn't set until well after midnight.
POSSIBLE BINOCULAR ASTEROIDS in SEPTEMBER
SEPT 1 NZST SEPT 30 NZDT
Mag Cons transit Mag Cons transit
(1) Ceres 8.7 Tau 6.06am 8.3 Tau 5.27am
(2) Pallas 8.7 Psc 12.55am 8.9 Aqr 11.40pm
(4) Vesta 7.9 Vir 3.02pm 7.9 Vir 3.02pm
(6) Hebe 9.1 Sgr 8.50pm 9.5 Sgr 8.12pm
(12) Victoria 9.3 Aql 9.44pm 10.1 Aql 9.06pm
(89) Julia 9.0 Aqr 11.31pm 9.6 Aqr 10.17pm
CERES is a morning object in Taurus during September. It rises at 12:57 am on the 1st and 12.21 am (NZDT) on the 30th. Ceres will be crossing the Hyades at first, going on to a close pass of Aldebaran mid-month. On the morning of the 14th when at their closest, the two will be less than a degree apart. Ceres will then be at magnitude 8.6, to the upper right of Aldebaran at 3am.
PALLAS is at opposition on September 9 with a magnitude 8.5. It rises at 6.57 pm on the 1st, to set 12 hours later. On the 30th it rises at 5.20pm NZDT. The asteroid moves from Pisces into Aquarius on the 24th.
VESTA, as an evening object, will be just over 5° to the right of Venus at the beginning of September. Over the following evenings Venus will draw ahead of the asteroid. On the 10, the crescent moon, at its closest to Venus for the month, will also be 5° above Vesta. On September 30 Vesta sets at 9.38 pm, NZDT.
HEBE, in Sagittarius, it is well placed in the evening sky setting well after midnight. On the 1st it sets at 4 am and at 3.38 am NZDT on the 30th.
VICTORIA at magnitude 9.4 is an evening object, setting, like Hebe, well after midnight. Victoria is some 20° from Hebe the two being at similar altitudes. By the 30th Victoria will have faded to magnitude 10.1
JULIA is observable much of the night, it rises before sunset on the 1st, setting the following morning at 5.35am. By the end of September it will have faded to magnitude 9.6, setting at 4.16 am NZDT.
-- Brian Loader
4. Beaumont Prize Writing Competition - Closes Sept. 1
The Auckland Astronomical Society advises new rules for the Beaumont Prize Writing Competition:
1. The article must be an original work, typed in acceptable language, capable of being included in the Society Journal. The Society will, at its absolute discretion, have the right to refuse to accept any entry that it deems inappropriate.
2. The article must be no longer than 1500 words and no shorter than 500 words.
3. No more than 3 entries per person can be submitted in any year.
4. The subject of the article must be about an astronomy topic or something that would be of interest or useful for people with an interest in amateur astronomy and/or astronomical science.
5. It does not have to be an article previously published in the Society Journal, but by entering it into the competition the author agrees to give the Auckland Astronomical Society (AAS) the right to use
or publish, with attribution, any articles submitted in AAS or RASNZ (Royal Astronomical Society of New Zealand) publications, websites and/or exhibitions to promote astronomy in New Zealand – including, but not limited to AAS and RASNZ journals, the New Zealand Astronomical Yearbook, AAS or RASNZ website and Facebook pages or in any publication, either printed or digital, that the Society deems appropriate. The publication of entry articles will be of charitable nature and not for profit. Any sponsors of the competition may also require to be allowed to use the submitted article in a non-commercial capacity. Copyright outside of those purposes outlined above will remain with the author.
6. The judge or judges for the competition will be appointed by the Society’s Council. The judge’s decision will be final and no correspondence will be entered into. The judge or judges or their immediate family will be ineligible to enter the competition.
7. The Society’s Council will, each year that the competition is conducted, decide what the prize or prizes and the number of such prizes if more than one.
8. The Society’s Council will decide when the competition will be held as well as the opening and closing dates for entries.
9. The competition will be open to all residents of New Zealand.
Closing date is September 1 and the entries can be sent to <journal@astronomy.org.nz> .
The word “Society in the context of these rules means “Auckland Astronomical Society” (AAS).
-- From the Auckland Astronomical Society's Journal, July 2021.
5. New Zealand Astrophotography Competition - Closes Sept. 21
The 2021 New Zealand Astrophotography Competition is now open for entries.
This year's competition will be judged by Robert Gendler, Robert is arguably one of the top deep sky astrophotographers in the world, he specializes in images of deep sky objects with very long exposure times. For more information on our judge please take a look at his work on his website at http://www.robgendlerastropics.com/
The competition has three main categories deep sky, nightscape and solar system, last year we introduced a new time-lapse category but this year we have decided to tweak the rules of this new category so make sure you read over the rules and conditions of entry before submitting your entries. See below.
Prizes include a 12 month subscription to Australian Sky & Telescope magazine, a $500 Celestron Australia Voucher, $500 NZD Sky-Watcher Australia Voucher, and a $300 Astronz gift voucher. The Auckland Astronomical Society will also provide a cash prize for each category winner.
The competition cutoff date is the 21st of September and the competition awards will be announced at the annual Burbidge dinner which is the Auckland Astronomical Society's premier annual event, keep an eye out on the society website for details on the forthcoming Burbidge dinner.
Conditions of entry and entry forms can be downloaded from the Auckland Astronomical Society website here at https://www.astronomy.org.nz/announcing-the-2021-new-zealand-astrophotography-competion-for-the-harry-williams-trophy/ "
-- From Jonathan Green, Director of the RASNZ Astrophotography Section, for the Auckland Astronomical Society.
6. Variable Star News
RS Ophiuchus (RS Oph) is a recurrent nova; in early August 2021 it was caught in outburst. The star was observed by Alexandre Amorum in its quiescent, pre-outburst, state at magnitude 11.2 on Aug 7.98 Universal Time. It was then reported to cvnet-ouburst@groups.io by Eddy Muyllaert (Belgium) on 8 August (Julian Day 20210808.9201) at reported magnitude 5.1. An independent discovery was made by Irish amateur Keith Geary. It is not currently possible to predict the timing of an outburst of this star and regular monitoring is required to capture these events. The last outburst was fifteen years ago.
The increase in magnitude of RS Oph from mag.11 to mag. 5 represents an increase in brightness of about six hundred times. The mechanism is the same as the usual novae, a spill-over of material from a giant star to its companion white dwarf, triggering a flare up in the denser star.
A number of observers have been able to monitor the decline in brightness. On the 11th and 12th of August the star was reported as still brighter than magnitude 6; Peter Williams and David Benn reporting it at mag 5.7. At the time of writing this article (August 17th) the star is sinking below magnitude 7.0 (visual). There are a good number of observations of the decline on the AAVSO database. The start of this recent outburst has now been characterised from some survey photos; results are given in Electronic Telegram No. 5017, Central Bureau for Astronomical Telegrams and there is also data on the AAVSO light curve plot.
Much of the information for this article has been drawn from Variable Stars South (VSS) Google discussion group. There is also an article at Sky and Telescope magazine- https://skyandtelescope.org/astronomy-news/recurrent-nova-rs-ophiuchi-just-blew-its-top/
Variable Stars South July 2021 Newsletter.
Following on from Tom Richard’s dissection of the period fitting process in VSS April 2021 Newsletter there are two new period analysis articles in the July 2021 issue: ”Deciphering the RV Grucis O-C diagram” by Mark Blackford and “The eclipsing binary FM Vel has an irregular period” by Tom Richards and Greg Crawford. The newsletters are free to access on the VSS website.
-- Alan Baldwin
7. Global Meteor Network
The Global Meteor Network (GMN) utilizes highly sensitive low-cost CMOS video cameras which run open-source meteor detection software on Raspberry Pi computers. Currently, over 450 GMN cameras in 30 countries are deployed. The main goal of the network is to provide long-term characterization of the radiants, flux, and size distribution of annual meteor showers and outbursts in the optical meteor mass range.
For background see https://arxiv.org/abs/2107.12335 and
https://globalmeteornetwork.org/
-- Tim Banks noted that no New Zealanders seem to be involved, so far. Thanks to Tim for passing on the links.
8. New Zealand Dark Sky Handbook
This is to announce a new book by John Hearnshaw, Emeritus Professor of Astronomy at the University of Canterbury.
The New Zealand Dark Sky Handbook is a comprehensive manual for all those who are interested in the fast growing topic of dark skies protection and the abatement of artificial light at night.
The book is in eight chapters, covering the following topics:
Chapter 1: Why protect dark skies?
Chapter 2: Properties of light and good lighting practices Chapter 3: Measuring light Chapter 4: The eye and human vision Chapter 5: Lighting ordinances and dark sky organizations Chapter 6: Dark sky places in New Zealand Chapter 7: Island dark sky places in the world Chapter 8: Astro-tourism and stargazing Index
The NZ Dark Sky Handbook is richly illustrated, with many figures in full colour, numerous tables of useful information, and explanations of complex topics in light measurement, physics, astronomy and lighting technology.
This is a highly multi-disciplinary subject. It calls on physics, astronomy, photometry, lighting technology, aesthetics, tourism, legal matters, human physiology, endocrinology, ecology, astrophotography, public outreach, geography, education and economics.
The NZ Dark Sky Handbook fills 230 A4 pages. It is self-published by the author. To obtain a copy, the purchase price is $28 (NZD) plus the costs of postage and packaging, if required ($8.60 for mailing within NZ, more for overseas). To order a copy, please email john.hearnshaw@canterbury.ac.nz or john.b.hearnshaw@gmail.com. Payment may be made by direct credit to the author’s bank account at Westpac
Bank: 03 1706 0010432 00.
The NZ Dark Sky Handbook was first published in June 2021. The first printing was sold out, and 100 additional copies have recently been printed. They are available now.
ISBN 978-0-473-57462-8
9. Galactic Fireworks: New Pictures of Nearby Galaxies
A team of astronomers has released new observations of nearby galaxies that resemble colourful cosmic fireworks. The images, obtained with the European Southern Observatory’s Very Large Telescope (ESO’s VLT), show different components of the galaxies in distinct colours, allowing astronomers to pinpoint the locations of young stars and the gas they warm up around them. By combining these new observations with data from the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, the team is helping shed new light on what triggers gas to form stars.
Astronomers know that stars are born in clouds of gas, but what sets off star formation, and how galaxies as a whole play into it, remains a mystery. To understand this process, a team of researchers has observed various nearby galaxies with powerful telescopes on the ground and in space, scanning the different galactic regions involved in stellar births.
“For the first time we are resolving individual units of star formation over a wide range of locations and environments in a sample that well represents the different types of galaxies,” says Eric Emsellem, an astronomer at ESO in Germany and lead of the VLT-based observations conducted as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) project. “We can directly observe the gas that gives birth to stars, we see the young stars themselves, and we witness their evolution through various phases.”
Emsellem, who is also affiliated with the University of Lyon, France, and his team have now released their latest set of galactic scans, taken with the Multi-Unit Spectroscopic Explorer (MUSE) instrument on ESO’s VLT in the Atacama Desert in Chile. They used MUSE to trace newborn stars and the warm gas around them, which is illuminated and heated up by the stars and acts as a smoking gun of ongoing star formation.
The new MUSE images are now being combined with observations of the same galaxies taken with ALMA and released earlier this year. ALMA, which is also located in Chile, is especially well suited to mapping cold gas clouds — the parts of galaxies that provide the raw material out of which stars form.
By combining MUSE and ALMA images astronomers can examine the galactic regions where star formation is happening, compared to where it is expected to happen, so as to better understand what triggers, boosts or holds back the birth of new stars. The resulting images are stunning, offering a spectacularly colourful insight into stellar nurseries in our neighbouring galaxies.
“There are many mysteries we want to unravel,” says Kathryn Kreckel from the University of Heidelberg in Germany and PHANGS team member. “Are stars more often born in specific regions of their host galaxies — and, if so, why? And after stars are born how does their evolution influence the formation of new generations of stars?”
Astronomers will now be able to answer these questions thanks to the wealth of MUSE and ALMA data the PHANGS team have obtained. MUSE collects spectra — the “bar codes” astronomers scan to unveil the properties and nature of cosmic objects — at every single location within its field of view, thus providing much richer information than traditional instruments. For the PHANGS project, MUSE observed 30 000 nebulae of warm gas and collected about 15 million spectra of different galactic regions. The ALMA observations, on the other hand, allowed astronomers to map around 100 000 cold-gas regions across 90 nearby galaxies, producing an unprecedentedly sharp atlas of stellar nurseries in the close Universe.
In addition to ALMA and MUSE, the PHANGS project also features observations from the NASA/ESA Hubble Space Telescope. The various observatories were selected to allow the team to scan our galactic neighbours at different wavelengths (visible, near-infrared and radio), with each wavelength range unveiling distinct parts of the observed galaxies. “Their combination allows us to probe the various stages of stellar birth — from the formation of the stellar nurseries to the onset of star formation itself and the final destruction of the nurseries by the newly born stars — in more detail than is possible with individual observations,” says PHANGS team member Francesco Belfiore from INAF-Arcetri in Florence, Italy. "PHANGS is the first time we have been able to assemble such a complete view, taking images sharp enough to see the individual clouds, stars, and nebulae that signify forming stars."
See the images at
https://www.eso.org/public/images/?search=eso2110
-- Thanks to Karen Pollard for passing on the link.
10. Centaurus A Imaged by Event Horizon Telescope
How do supermassive black holes create powerful jets? To help find out, the Event Horizon Telescope (EHT) imaged the centre of the nearby active galaxy Centaurus A. Its image showed a region equivalent to the size of a golf ball on the moon, resolving details less than one light-day across at Cen A's distance of 11 million light-years. The new image shows what may look like two jets -- but is actually two sides of a single jet. This newly discovered jet-edge brightening does not solve the jet-creation mystery, but does imply that the particle outflow is confined by a strong pressure -- possibly involving a magnetic field.
The EHT is a coordination of radio telescopes from around the Earth -- from the Caltech Submillimeter Observatory in Hawaii, USA, to ALMA in Chile, to NOEMA in France, and more. The EHT will continue to observe massive, nearby black holes and their energetic surroundings.
The cascade of images showing Cen A (NGC 5128) from it largest, taking up more sky than many moons to its now finest can be seen at https://apod.nasa.gov/apod/ap210804.html
11. Mars Sampling Fails
After drilling into its first rock on Mars but failing to capture it in a storage tube on 6 August, NASA’s Perseverance rover is rolling onwards. Rather than make a second attempt now at drilling in the same geologically interesting area in Mars’s Jezero Crater, it will instead drill into different terrain next month, in the hope that those rocks will be more amenable to coring.
After a few days assessing what went wrong during the first attempt, NASA announced on 11 August that the rover had pulverized the sampled rock into powder and small fragments. They fell to the crater floor rather than sliding into the tube, as an intact core would have done.
“It took a few minutes for this reality to sink in,” wrote Louise Jandura, the chief engineer for sampling and caching at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, which operates the rover, in an 11 August update.
Perseverance is attempting to become the first mission to drill and collect a suite of rock cores from the Martian surface. It is planned that other spacecraft will eventually retrieve the samples and bring them back to Earth, where scientists can study them. “This is just another reminder that there are still a lot of unknowns about Mars,” says Meenakshi Wadhwa, a planetary scientist at Arizona State University in Tempe who is NASA’s principal scientist for the sample-retrieval effort. “This planet still has the capacity to surprise us when we least expect it.”
Researchers were particularly excited about the rover’s first drilling attempt. They had selected one of the flat rocks that make up much of the floor of Jezero Crater, where the rover landed in February, and which it has been exploring since then. Preliminary exploration of those flat rocks — dubbed the ‘cratered floor fractured rough’ — suggested that they might be volcanic in origin, perhaps even from an ancient lava flow. Collecting a volcanic rock from Mars and returning it to Earth would allow geologists to date its formation precisely, and thus pin down a chronology for much of Mars’s geological history.
But despite initial images suggesting that Perseverance had successfully drilled 7 centimetres into the surface and extracted a slim cylinder of intact rock, NASA later discovered that the sampling tube that had been automatically sealed and stored inside the rover’s belly was empty.
The rock was crumblier than engineers had expected, says Jennifer Trosper, the mission’s project manager at the JPL. Perhaps there was a hard layer of rock hiding looser material beneath it, or perhaps there were large voids in the rock that caused it to collapse. “There wasn’t anything obvious,” she says, to suggest “that this might disintegrate or be pulverized when we cored it”.
Rather than try again with the cratered floor fractured rough, Perseverance has already departed the area and is heading towards a region named South Séítah, which probably contains layered sedimentary rocks that are more like the Earth rocks that engineers drilled during tests before the mission’s launch. “We are going to step back and do something we are more confident of,” says Trosper. The rover will try to drill a core there, perhaps in early September. When it does, engineers will pause the automated drilling process to check whether a core has been extracted before the rover takes the next steps of sealing the tube and storing it away.
The empty tube it stored on 6 August will serve as a sample of the Martian atmosphere, which the Perseverance team intended to collect at some point during the mission, although not so soon. The rover carries 43 sampling tubes, so 42 remain. The ultimate goal is to fill about 35 tubes with Martian rock and soil, from various parts of Jezero Crater. They would return to Earth no earlier than 2031.
Engineers tested the Perseverance drilling system more than 100 times on a range of rocks on Earth, to prepare for everything the rover might encounter on Mars. But the cratered floor fractured rough proved beyond the system’s experience.
-- See the entire Nature article with images at https://www.nature.com/articles/d41586-021-02208-z?
See also https://www.space.com/perseverance-rover-mars-sample-attempt-fails
12. James Webb Telescope to be Renamed?
NASA is considering whether to rename its flagship astronomical observatory, given reports alleging that James Webb, after whom it is named, was involved in persecuting gay and lesbian people during his career in government. Keeping his name on the US$8.8-billion James Webb Space Telescope (JWST) — set to launch later this year — would glorify bigotry and anti-LGBT+ sentiment, say some astronomers. But others say there is not yet enough evidence against Webb, who was head of NASA from 1961 to 1968, and they are withholding judgement until the agency has finished an internal investigation.
The JWST, which will peer into the distant reaches of the cosmos, is NASA’s biggest astronomical project in decades, so the stakes are high. In May, citing Webb’s purported involvement in discrimination, four prominent astronomers launched a petition to change the telescope’s name. It has amassed 1,250 signatories, including scientists who have been awarded observing time on the telescope.
NASA’s acting chief historian, Brian Odom, is working with a non-agency historian to review archival documents about Webb’s policies and actions, according to agency officials. Only after the investigation concludes will NASA decide what to do.
Former NASA administrator Sean O’Keefe named the JWST after Webb in 2002, when the telescope was in the early stages of development. It was a unilateral decision that took many by surprise, because NASA’s telescopes are typically named after scientists. Webb, who died in 1992, was a bureaucrat who held several administrative roles in the US government.
O’Keefe chose the name because Webb had advocated that NASA keep science as a key part of its portfolio in the 1960s, even as the Apollo programme of human space exploration soaked up most of the agency’s attention and budget. O’Keefe tells Nature he was not aware of the accusations when he picked the name, and he supports keeping it unless more information surfaces. “Without James Webb’s leadership, there may have been no telescope or much of anything else at NASA noteworthy of a naming controversy,” he says.
See all the long Nature article at https://www.nature.com/articles/d41586-021-02010-x?
13. Gifford-Eiby Lecture Fund
The RASNZ administers the Gifford-Eiby Memorial Lectureship Fund to
assist Affiliated Societies with travel costs of getting a lecturer
or instructor to their meetings. Details are in RASNZ By-Laws Section
H and at http://rasnz.org.nz/rasnz/ge-fund
The application form is at
http://rasnz.org.nz/Downloadable/RASNZ/GE_Application2019.pdf
14. Kingdon-Tomlinson Fund
The RASNZ is responsible for recommending to the trustees of the Kingdon
Tomlinson Fund that grants be made for astronomical projects. The grants may be to any person or persons, or organisations, requiring funding for any projects or ventures that promote the progress of astronomy in New Zealand. The deadline for this round of the Kingdon-Tomlinson Grants is 1st November 2020. Full details are set down in the RASNZ By-Laws, Section J. Information on the K-T Fund is at
http://rasnz.org.nz/rasnz/kt-fund
Send applications to the RASNZ Executive Secretary at rasnz.secretary@gmail.com.
The application form at
http://rasnz.org.nz/Downloadable/RASNZ/KT_Application2019.pdf
15. How to Join the RASNZ
RASNZ membership is open to all individuals with an interest in
astronomy in New Zealand. Information about the society and its
objects can be found at
http://rasnz.org.nz/rasnz/membership-benefits
A membership form can be either obtained from treasurer@rasnz.co.nz or
by completing the online application form found at
http://rasnz.org.nz/rasnz/membership-application
Basic membership for the 2021 year starts at $40 for an ordinary
member, which includes an electronic subscription to our journal
'Southern Stars'.
16. Quotes
"If liberty means anything at all, it means the right to tell people what they do not want to hear." -- George Orwell. (From Susie Dent's 'Word Perfect' p.181.
"I chose to pursue a career in physics because there the truth isn't so easily bent." -- Angela Merkel.
"I've learned from my mistakes and I'm sure I can repeat them exactly. -- Peter Cook.
Alan Gilmore Phone: 03 680 6817
P.O. Box 57 alan.gilmore@canterbury.ac.nz
Lake Tekapo 7945
New Zealand
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December Celestial Calendar by Dave Mitsky
August Celestial Calendar by Dave Mitsky
All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)
8/1 The Moon is 1.7 degrees south-southeast of Uranus at 3:00; a double Galilean shadow transit begins at 10:08; Mercury is in superior conjunction with the Sun (1.342 astronomical units from the Earth, latitude 6.9 degrees) at 14:00; the Curtiss Cross, an X-shaped clair-obscur illumination effect located between the craters Parry and Gambart, is predicted to be visible at 22:20
8/2 Saturn (magnitude +0. 2, apparent size 18.6") is at opposition at 6:00; the Moon is at apogee, subtending 29' 33" at a distance of 404,409 kilometers (251,289 miles) at 7:35; the Moon is 4.8 degrees southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 11:00
8/3 The Moon is at the ascending node (longitude 68.9 degrees) at 3:00; the Moon is 5.6 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 5:00; Mercury is at its northernmost latitude from the ecliptic plane (7.0 degrees) at 6:00
8/5 The Moon is 1.1 degrees north of the bright open cluster M35 in Gemini at 2:00; asteroid 4 Juno (magnitude +10.8 ) is stationary in Ophiuchus at 4:00
8/6 The Moon is 6.7 degrees south of the first-magnitude star Castor (Alpha Geminorum) at 15:00; the Moon is 3.1 degrees south of the first-magnitude star Pollux (Beta Geminorum) at 20:00
8/7 The astronomical cross-quarter day known as Lammas or Lughnasadh, the midpoint between the summer solstice and the autumnal equinox, occurs today; the Moon is 3.0 degrees north-northeast of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 22:00
8/8 A double Galilean shadow transit begins at 12:42; New Moon (lunation 1220) occurs at 13:50
8/9 The Moon is 3.2 degrees north-northeast of Mercury at 6:00; the Moon is 4.5 degrees north-northeast of the first-magnitude star Regulus (Alpha Leonis) at 16:00
8/10 The Moon is 4.0 degrees north-northeast of Mars at 4:00; the Sun enters the constellation of Leo, at longitude 138.2 degrees on the ecliptic, at 15:00
8/11 The Moon is 3.9 degrees north-northeast of Venus at 11:00
8/12 Mercury is 1.1 degrees north-northeast of Regulus at 1:00; the peak of the Perseid meteor shower (a zenithal hourly rate of 100 or more per hour) is predicted to occur at 19:00; asteroid 349 Demboska (magnitude +9.8 ) is at opposition in Piscis Austrinus at 21:34
8/13 The Moon is 5.5 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 15:00
8/15 The Lunar X, also known as the Werner or Purbach Cross, an X-shaped clair-obscur illumination effect involving various ridges and crater rims located between the craters La Caille, Blanchinus, and Purbach, is predicted to be visible at 10:28; a double Galilean shadow transit begins at 14:41; a double Galilean shadow transit begins at 15:17; First Quarter Moon occurs at 15:20; a triple Galilean satellite transit occurs at 15:31
8/16 Mars and Neptune are at heliocentric opposition (longitudes 171.6 degrees and 351.6 degrees) at 13:00; the Moon is at the descending node (longitude 247.6 degrees) at 16:00; the Moon is 4.4 degrees north-northeast of the first-magnitude star Antares (Alpha Scorpii) at 22:00
8/17 The Moon is at perigee, subtending 32' 22'' from a distance of 369,125 kilometers (229,363 miles), at 9:16
8/19 Mercury is 0.1 degrees south of Mars at 4:00; asteroid 43 Ariadne is at opposition (magnitude +9.6) in Aquarius at 19:10
8/20 Uranus is stationary, with retrograde motion to begin, at 0:00; Jupiter is at opposition (magnitude -2.9, apparent size 49.1") at 0:00
8/21 The Moon is 3.6 degrees south of Saturn at 0:00
8/22 The Moon is 3.7 degrees southeast of Jupiter at 8:00; Full Moon (known as the Fruit, Grain, Green Corn, or Sturgeon Moon) occurs at 12:02; a double Galilean shadow transit begins at 18:42; the Sun's longitude is 150 degrees at 22:00
8/24 The Moon is 3.7 degrees southeast of Neptune at 6:00; asteroid 89 Julia (magnitude +9.0) is at opposition in Aquarius at 14:22
8/25 The Martian northern hemisphere summer solstice occurs at 0:00
8/26 Mercury is at the descending node through the ecliptic plane at 15:00
8/28 The Moon is 1.4 degrees southeast of Uranus at 11:00
8/29 Venus is at the descending node through the ecliptic plane at 5:00; the Moon is 4.6 degrees southeast of M44 at 19:00; a double Galilean shadow transit begins at 22:43
8/30 The Moon is at apogee, subtending 29' 34" at a distance of 404,098 kilometers (251,096 miles) at 2:22; the Moon is at the ascending node (longitude 66.2 degrees) at 5:00; Last Quarter Moon occurs at 7:13; the Moon is 5.8 degrees north-northwest of Aldebaran at 13:00
8/31 The Curtiss Cross is predicted to be visible at 9:42
John Flamsteed, Christian Mayer, Pierre François André Méchain, Maria Mitchell, and Otto Struve were born this month.
The gibbous phase of Mars was first observed by Francesco Fontana on August 24, 1638. Abraham Ihle discovered the globular cluster M22 on August 26, 1665. Nicolas Sarabat discovered Comet C/1729 P1 (Sarabat) on August 1, 1729. Caroline Herschel discovered Comet C/1786 P1 (Herschel) on August 1, 1786. The Saturnian satellite Enceladus was discovered by William Herschel on August 28, 1789. Dominique Dumouchel was the first person to observe the return of Comet 1P/Halley on August 5, 1835. John Russell Hind discovered asteroid 7 Iris on August 13, 1847. Asaph Hall discovered Deimos on August 11, 1877 and Phobos on August 17, 1877. The first extragalactic supernova, S Andromedae, was discovered by Ernst Hartwig on August 20, 1885. David Jewitt and Jane Luu discovered the trans-Neptunian object (15760) 1992 QB1 on August 30, 1992. The Jovian satellite 2002 Laomedeia was discovered by Matthew Holman on August 13th, 2002.
The peak of the Perseid meteor shower takes place on the night of August 11th/August 12th and is not compromised by moonlight. The periodic comet 109P/Swift-Tuttle is the source of Perseid meteors. The shower’s radiant lies just to the southeast of the Double Cluster (NGC 869 and NGC 884). For more on this year’s Perseids, see page 52 to page 55 of the August 2021 issue of Astronomy and page 48 of the August 2021 issue of Sky & Telescope or click on https://earthsky.org/.../everything-you-need-to-know... and https://www.imo.net/viewing-the-perseid-meteor-shower-in.../
Information on passes of the ISS, the USAF’s X-37B, the HST, Starlink, and other satellites can be found at http://www.heavens-above.com/
The Moon is 21.8 days old, is illuminated 47.4%, subtends 29.5 arc minutes, and is located in Aries on August 1st at 00:00 UT. The Moon is at its greatest northern declination on August 6th (+25.6 degrees) and its greatest southern declination on August 19th (-25.8 degrees). Longitudinal libration is at a maximum of +5.4 degrees on August 24th and a minimum of -4.9 degrees on August 9th. Latitudinal libration is at a maximum of +6.6 degrees on August 23rd and a minimum of -6.6 degrees on August 10th. Favorable librations for the following lunar features occur on the indicated dates: Crater Piazzi on August 4th, Crater Hayn on August 19th, Crater Compton on August 21st, and Crater Boss F on August 22th. The Moon is at apogee (at a distance 63.41 Earth-radii) on August 2nd and again (at a distance 63.26 Earth-radii) on August 30th and at perigee (at a distance of 57.87 Earth-radii) on August 17th. New Moon (i.e., the dark of the Moon) occurs on August 8th. Full Moon, a Blue Moon by the classic definition of the third Full Moon in a summer that has four, occurs on August 22nd. Browse http://www.lunar-occultations.com/iota/iotandx.htm for information on lunar occultation events. Visit https://saberdoesthestars.wordpress.com/.../saber-does.../ for tips on spotting extreme crescent Moons and https://curtrenz.com/moon.html for Full Moon and other lunar data. Browse https://skyandtelescope.org/wp-content/uploads/MoonMap.pdf and https://nightsky.jpl.nasa.gov/docs/ObserveMoon.pdf for simple lunar maps. Click on http://astrostrona.pl/moon-map for an excellent online lunar map. Visit http://www.ap-i.net/avl/en/start to download the free Virtual Moon Atlas. Consult http://time.unitarium.com/moon/where.html for current information on the Moon and https://www.fourmilab.ch/earthview/lunarform/lunarform.html for information on various lunar features. See https://svs.gsfc.nasa.gov/4874 for a lunar phase and libration calculator and https://quickmap.lroc.asu.edu/?extent=-90,-25.2362636,90,25.2362636&proj=10&layers=NrBsFYBoAZIRnpEoAsjYIHYFcA2vIBvAXwF1SizSg for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on https://www.calendar-12.com/moon_calendar/2021/august for a lunar phase calendar for this month. Times and dates for the lunar crater light rays predicted to occur this month are available at http://www.lunar-occultations.com/rlo/rays/rays.htm
The Sun is located in Cancer on August 1st. It enters the constellation of Leo on August 10th and achieves an ecliptic longitude of 150 degrees on August 21st.
Brightness, apparent size, illumination, distance from the Earth in astronomical units, and location data for the planets and Pluto on August 1: Mercury (magnitude -2.1, 5.0", 100% illuminated, 1.34 a.u., Cancer), Venus (magnitude -3.9, 12.7", 82% illuminated, 1.32 a.u., Leo), Mars (magnitude +1.8, 3.7", 99% illuminated, 2.56 a.u., Leo), Jupiter (magnitude -2.8, 48.5", 100% illuminated, 4.07 a.u., Aquarius), Saturn (magnitude +0.2, 18.6", 100% illuminated, 8.94 a.u., Capricornus), Uranus (magnitude +5.7, 3.6", 100% illuminated, 19.57 a.u. on August 16th, Aries), Neptune (magnitude +7.8, 2.4", 100% illuminated, 29.04 a.u. on August 16th, Aquarius), and Pluto (magnitude +14.3, 0.1", 100% illuminated, 33.45 a.u. on August 16th, Sagittarius).
This month Mercury, Venus, and Mars are located in the west, Jupiter and Neptune in the east, and Saturn in the southeast during the evening. At midnight, Jupiter and Saturn can be found in the south, Uranus in the east, and Neptune in the southeast. Uranus is in the southeast, and Jupiter, Saturn, and Neptune in the southwest in the morning sky.
Mercury is in superior conjunction on August 1st and is at its greatest heliocentric latitude north on August 3rd. Mercury and Mars are in close conjunction on the evening of August 18th (August 19th UT), with a separation of just seven arc minutes. The speediest planet will be at the descending node on August 26th. Mercury will become visible again in the evening sky towards the end of the month but it will be the worst evening apparition of 2021 for mid-northern hemisphere observers.
During August, Venus changes little in brightness but increases in angular size from 12.7 arc seconds to 15.0 arc seconds, while it drops in illumination from 82% to 73%. Venus continues its descent, despite increasing in solar elongation from 33 to 40 degrees, crossing the celestial equator on August 17th. A slender waxing crescent Moon passes four degrees to the north of the planet on August 11th.
Mars may be visible with difficulty in early August. Mars sets about an hour after the Sun. Its elongation from the Sun drops from 22 to 12 degrees this month. A slender waxing crescent Moon passes about four degrees north of Mars on the evening of August 9th (August 10th UT), which may be the last time that the Red Planet is visible until the end of the year. Mars and Neptune are at heliocentric opposition on August 16th. Mars and Mercury are in conjunction on August 18th-August 19th. Mars shines at magnitude +1.8 and subtends only 3.6 arc seconds as August comes to an end.
Jupiter changes only slightly in brightness and apparent size this month. It reaches opposition on August 20th. On that date, Jupiter is 14 degrees south of the celestial equator in eastern Capricornus, is 33 light minutes from the Earth, and subtends 49.1 arc seconds. The Full Moon passes four degrees to the south of Jupiter on August 22nd. An article on observing Jupiter can be found on pages 40 to 45 of the August 2021 issue of Astronomy. An article on observing Jupiter and Saturn appears on pages 49 and 50 of the August 2021 issue of Sky & Telescope. From 2:42 to 5:07 UT on the night of August 11th/August 12th, just one of Jupiter's satellites, namely Callisto, is visible. Callisto is located 10 arc minutes due east of the planet, while Io and Ganymede are behind it and Europa and its shadow are transiting across Jupiter's disk. In just six minutes, from 5:07 to 5:13 UT, Ganymede, Io, and Europa respectively reappear from occultation. Double Galilean satellite shadow transits occur on August 1st, August 8th, August 15th, August 22nd, and August 29th. Two shadow transits and a triple satellite transit, that is best seen from Asia and Australasia, take place on August 15th. Information on Great Red Spot transit times and Galilean satellite events is available on pages 50 and 51 of the August 2021 issue of Sky & Telescope and online at http://www.skyandtelescope.com/.../interactive-sky.../ and https://www.projectpluto.com/jeve_grs.htm
When Saturn achieves opposition on August 2nd, it is 18 degrees south of the celestial equator and is 74 light minutes from the Earth. At that time, the planet's disk subtends 18.6 arc seconds and its rings span almost 42 arc seconds and are inclined by 18 degrees. On August 20th, the waxing gibbous Moon passes four degrees to the south of Saturn. Titan is positioned north of Saturn on August 3rd and August 19th and south of it on August 11th and August 26th/27th. Saturn's peculiar satellite Iapetus shines faintly at almost 12th magnitude as it reaches eastern elongation almost nine arc minutes east of the planet on August 12th. It reaches inferior conjunction 50 arc seconds from Saturn on August 31st. For information on Saturn’s satellites, browse http://www.skyandtelescope.com/.../interactive-sky.../
Uranus is located in southern Aries. It forms an equilateral triangle with Omicron Arietis (magnitude +5.8 ) and Sigma Arietis (magnitude +5.5). The waning gibbous Moon passes three degrees southeast of Uranus on the night of August 10th/August 11th. Uranus reaches its first stationary point on August 20th. The seventh planet achieves its highest declination (almost 16 degrees) since the 1960s this month. Visit http://www.nakedeyeplanets.com/uranus.htm for a finder chart. The positions of the planet's brightest satellites can be determined using the interactive observing tool at https://skyandtelescope.org/.../the-elusive-moons-ofuranus/
Neptune can be found in eastern Aquarius about five degrees east of the fourth-magnitude star Phi Aquarii. Mars and Neptune are at heliocentric conjunction on August 16th. The waning gibbous Moon passes less than four degrees southeast of Neptune on August 24th. Browse http://www.nakedeyeplanets.com/neptune.htm for a finder chart. Triton, Neptune's brightest satellite, can be located using the interactive observing tool at https://skyandtelescope.org/.../sky-telescopes-triton.../
The dwarf planet Pluto is located in eastern Sagittarius about 10 degrees northeast of the third-magnitude star Tau Sagittarii. Finder charts can be found at pages 48 and 49 of the July 2021 issue of Sky & Telescope and on page 243 of the RASC Observer’s Handbook 2021.
For more on the planets and how to locate them, see http://www.nakedeyeplanets.com/
The periodic comet 4P/Faye heads eastward through Taurus during August. This comet has a period of 7.6 years and shines at approximately tenth magnitude as it passes just south of the faint nebula NGC 1554/5 on August 21st and into the border of the bright open cluster NGC 1647 on August 30th. Visit http://cometchasing.skyhound.com/ and http://www.aerith.net/comet/future-n.html and https://cobs.si/ for information on comets visible this month.
Asteroid 89 Julia shines at ninth magnitude as it travels northwestward through Aquarius this month, passing about one degree south of Gamma Aquarii on August 6th and just south of Sadalmelik (Alpha Aquarii) on August 21st. It reaches opposition on August 24th. Other asteroids brighter than magnitude +11.0 reaching opposition include 43 Ariadne, 80 Sappho, and 349 Dembowska. For information on asteroid occultations taking place this month, see http://www.asteroidoccultation.com/2020_08_si.htm
A wealth of current information on solar system celestial bodies is posted at http://nineplanets.org/ and http://www.curtrenz.com/astronomy.html
Information on the celestial events transpiring each week can be found at https://stardate.org/nightsky and http://astronomy.com/skythisweek and http://www.skyandtelescope.com/observing/sky-at-a-glance/
Free star maps for this month can be downloaded at http://www.skymaps.com/downloads.html and https://www.telescope.com/content.jsp...
Data on current supernovae can be found at http://www.rochesterastronomy.org/snimages/
Finder charts for the Messier objects and other deep-sky objects are posted at https://freestarcharts.com/messier and https://freestarcharts.com/ngc-ic and https://www.cambridge.org/.../seasonal_skies_july-september
Telrad finder charts for the Messier Catalog are posted at http://www.custerobservatory.org/docs/messier2.pdf
Information pertaining to observing some of the more prominent Messier galaxies can be found at http://www.cloudynights.com/.../358295-how-to-locate.../
Freeware sky atlases can be downloaded at http://www.deepskywatch.com/.../Deep-Sky-Hunter-atlas... and https://www.cloudynights.com/.../free-mag-7-star-charts... and https://allans-stuff.com/triatlas/
Author Phil Harrington offers an excellent freeware planetarium program for binocular observers known as TUBA (Touring the Universe through Binoculars Atlas), which also includes information on purchasing binoculars, at http://www.philharrington.net/tuba.htm
Stellarium and Cartes du Ciel are two excellent freeware planetarium programs that are available at http://stellarium.org/ and https://www.ap-i.net/skychart/en/start
Deep-sky object list generators can be found at http://www.virtualcolony.com/sac/ and https://telescopius.com/ and http://tonightssky.com/MainPage.php
Sixty binary and multiple stars for August: 5 Aquilae, Struve 2404, 11 Aquilae, Struve 2426, 15 Aquilae, Struve 2449, 23 Aquilae, Struve 2532, Pi Aquilae, 57 Aquilae (Aquila); Beta Cygni (Albireo), 16 Cygni, Delta Cygni, 17 Cygni (Cygnus); 41 & 40 Draconis, 39 Draconis, Struve 2348, Sigma Draconis, Struve 2573, Epsilon Draconis (Draco); 95 Herculis, 100 Herculis, Struve 2289, Struve 2411 (Hercules); Struve 2349, Struve 2372, Epsilon-1 & Epsilon-2 Lyrae (the Double-Double), Zeta-2 Lyrae, Beta Lyrae, Otto Struve 525, Struve 2470 & Struve 2474 (the Other Double-Double) (Lyra); 67 Ophiuchi, 69 Ophiuchi, 70 Ophiuchi, Struve 2276, 74 Ophiuchi (Ophiuchus); Mu Sagittarii, Eta Sagittarii, 21 Sagittarii, Zeta Sagittarii, H N 119, 52 Sagittarii, 54 Sagittarii (Sagittarius); Struve 2306, Delta Scuti, Struve 2373 (Scutum); Struve 2296, Struve 2303, 59 Serpentis, Theta Serpentis (Serpens Cauda); Struve 2445, Struve 2455, Struve 2457, 4 Vupeculae, Struve 2521, Struve 2523, Struve 2540, Struve 2586, Otto Struve 388, Struve 2599 (Vulpecula)
Notable carbon star for August: V Aquilae
Eighty deep-sky objects for August: B139, B142, B143, NGC 6709, NGC 6738, NGC 6741, NGC 6751, NGC 6755, NGC 6772, NGC 6778, NGC 6781, NGC 6804, PK64+5.1 (Aquila); NGC 6819, NGC 6826, NGC 6834, (Cygnus); NGC 6643, NGC 6742 (Draco); DoDz 9 (Hercules); M56, M57, NGC 6703, NGC 6791, Ste1 (Lyra); NGC 6572, NGC 6633 (Ophiuchus); H20, M71 (Sagitta); B86, B87, B90, B92, B93, M8, M17, M18, M20, M21, M22, M23, M24, M25, M28, M54, M55, M69, M70, M75, NGC 6520, NGC 6544, NGC 6546, NGC 6553, NGC 6565, NGC 6603, NGC 6818, NGC 6822 (Sagittarius); IC 4703, IC 4756, M16, NGC 6604 (Serpens Cauda); B100, B101, B103, B104, B110, B111, B113, Bas 1, IC 1295, M11, M26, NGC 6649, NGC 6712 (Scutum); Cr 399 (asterism), M27, NGC 6802, NGC 6823, NGC 6834, NGC 6940, St 1 (Vulpecula)
Top ten binocular deep-sky objects for August: Cr 399, IC 4756, M8, M11, M17, M22, M24, M25, M27, NGC 6633 (IC 4756 and NGC 6633 are collectively known as the Binocular Double Cluster)
Top ten deep-sky objects for August: M8, M11, M16, M17, M20, M22, M24, M27, M55, M57
Challenge deep-sky object for August: Abell 53 (Aquila)
The objects listed above are located between 18:00 and 20:00 hours of right ascension.
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Minor Planet Occultation Updates:
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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
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Reddit
https://www.reddit.com/user/Edwin_Rod_NZ
Quaroa
https://www.quora.com/q/astronomyinnewzealand
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.
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