September 2020 by Jamie Canfield, Secretary

President’s Notes MONTHLY MEETING By Terry Phillips Shelter in Place Remote General Assembly Meeting ast month we had an in-depth panel discussion with Astronomy Technology Today’s Stuart Parkerson and Explore Scientific’s Scott LRoberts about the state of the amateur astronomy business and the impact on it of the Covid-19 pandemic. Both agreed that the sector has seen a pretty good bump up as many people turned to astronomy as a Friday, Nov. 13, 2020 hobby that can help maintain one’s sanity in a locked down world. The importance of astronomy outreach was particularly emphasized, and I 7:30 PM was truly amazed at the amount of online astronomy content Scott is producing. He is literally streaming daily features at Explore Alliance Live and his YouTube channel is feeding into four main forums: Explore Now, You should have received a Global Star Party, OpenGOTO, and How To. In the past few months Scott has hosted over 20 Global Star Parties and OpenGOTO forum has put out link via email to join the ZOOM over 100 informative videos. He is frequently bringing in some of the big virtual meeting. names in the astronomy community to present. Head over to https:// explorescientificusa.com/pages/explore-alliance-live to find out more If you have not received the Zoom meeting email, about tapping into this rich fount of astronomical knowledge and exper- contact [email protected] for access tise. information prior to the meeting or The work that Scott and others are doing is making me feel like AAS is call Dawn (512-663-2249) or Tim (512-577-8340) at the start of the meeting for help connecting. taking really baby steps into the online media outreach pond. So, we’ve had to learn a lot about Zoom and YouTube the past few months. I finally managed to get setup to simulcast our Zoom GA meetings to our pre- viously existing but mostly dormant AustinAstro YouTube channel. And this week I finished downloading all our past Zoom meetings sand up- loaded them to the YouTube channel. You can review our past meetings by going to https://youtube.com and searching for AustinAstro. If you want access to maintain content on the YouTube channel contact Sean Leary ([email protected]).

I sent an email blast to the membership this week to let everybody know

Sidereal Times Vol. 52 Issue 11 Banner: Oct. 2020 Image of the Month: Trew Hoffman, North America Nebula in SHO http://www.austinastro.org/

Sidereal Times is the official monthly publication of the Austin Astronomical Sidereal Times • November 2020 • 1 Society. President’s Notes Continued 1-2 Presidents Notes November Guest Speaker that we have completed a deal with Stuart Parkerson to allow our members to read Astronomy Technology Today online at no cost. This is a terrific source of information about astronomy related gear. Let us know at [email protected] if you missed the instructions on how to set this up. 4 On the Horizon AAS VP Report In the same email I let everybody know that we received an invitation for members to join a series of Online Viewing Sessions being produced the astronomy society in Kalamazoo Michigan (KAS). They have a nice automated observatory located in Arizona Sky Village near Portal AZ. They are at 4,500 ft with Bortle 2 skies. 5 The ALCORNER The featured instrument is a quartz 20” Plane Wave CDK with a TAK FSQ-106ED refractor riding shotgun. They are hosting monthly sessions. You have to register for each session, but it is easily done at https://www. kasonline.org/viewing.html . The meetings are hosted on Zoom and simulcast to YouTube. I am looking 6 Outreach Report forward to seeing how KAS implements online star parties. & Calendar of Events Tim Brown sent an all members email this week discussing and seeking input on how best to conduct small, covid safe star parties at Bad Wolf Ranch. Many members feel that it is safe if proper precautions are taken. Please let Tim, know your thoughts about this, and if a consensus can be reached, we may try to hold a party 7 The International Space Station in December.

I’ve been watching the major planets continue to put on a good show in the evening hours. In recent days 8-9 Bad Wolf Ranch I’ve been out walking after sunset and I’ve finally been able to detect a nightly closure as Jupiter is about to lap Saturn. In about six weeks the two will close to only 10 arcminutes. They will still be distinguishable as two bodies barely, but if you put a telescope on them, you’ll be in for a real treat. They will be low in the west 10-12 Pedernales Report November 2020 just after sunset, so go scout yourself a viewing spot with a nice clear southwestern horizon. You won’t want to miss this. 13-14 Observing Targets November 2020

Terry

November Meeting Guest Speaker: Byron Miller Topic: “Backyard Astrophotography - Deep Space Imaging for Amateur Astronomers.”

Club webmaster Byron Miller’s presentation will be on “Backyard Astrophotography - Deep Space Imaging for Amateur Astrono- mers.” From proper polar alignment to dealing with light pollution, we’ll explore the ways in which you can enjoy the cosmos and explore the universe through Astrophotography from the comfort of your own backyard.

2 •November 2020 • Sidereal Times Inside This Issue

1-2 Presidents Notes November Guest Speaker 15-16 The Discoveries of Galileo – Part 4: Venus 4 On the Horizon AAS VP Report 17-19 Image Of The Month & Members Image Gallery 5 The ALCORNER 20 Treasurer’s Report 6 Outreach Report & Calendar of Events 21-23 GA and EC Minutes

7 The International Space Station 24 Membership Cards

8-9 Bad Wolf Ranch 25 Joining AAS

10-12 Pedernales Report November 2020 26 2020-2021 Officers List -vacant positions 13-14 Observing Targets November 2020

AAS Affiliations

http://darksky.org/ https://nightsky.jpl.nasa.gov

https://www.astroleague.org/ http://www.tsgc.utexas.edu/

Sidereal Times • November 2020 • 3 On the Horizon: General Assembly Meetings By Michael E. Marotta, Vice President

December 11 Traditional Austin Astronomical Society Holiday Party. As close as virtually possible to a social gathering. Any and all attending members are invited to bring their 2-minute video or slide presentation to share with us. After the (short) business meeting, we will set up into Zoom “chat rooms” for small groups. At the end of the night, we will announce the winner of the “Image of the Year” award. Contestants are the 12 “Image of the Month” winners. Members will have voted via the AAS website.

January 8, 2021 “Spectroscopy” by Tom Field, inventor of spectroscopy tools for educators and hobbyists. It is now possible for amateur astronomers to image, record, and analyze the spectra of our targets. Spectroscopy reveals chemical sig- natures, red shifts, and blue shifts. Modern equipment screws into your telescope eyepiece or camera objective. Computer software supports your analysis of your images.

February 12, 2021 Young Stars in Our Neighborhood by Ronan M. Kerr, University of Texas. The Sco-Cen (Scorpius-Centaurus) association consists of spectral classes O and B. Kerr’s research is identi- fying some new young stellar groups first the time. His presentation will explain the star formation history and structure found in Sco-Cen, and reveal the larger-scale architecture of star formation in our stellar neighborhood.

March 12, 2021: To be Announced.

April 9, 2021: The Heaven Watcher’s Observatory with Rev. Jason Fry and Rob Teeter of Teeter’s Telescopes (https://www.teeterstelescopes.com) maker of custom-built (“be- spoke”) instruments such the one shown here with Jason Fry who views the sky from his “Cielo Vista Observatory” seven miles south of Alpine, between Fort Davis and Big Bend.

Upcoming: Dr. Mariba Jah, University of Texas, on non-gravitational orbit plotting.

Redshift—The October 2020 Meeting with Scott Roberts of Explore Scientific and Stuart Parkerson of Astronomical Technology Today. Archived on YouTube here: https://www.youtube.com/watch?v=Ubx- qbMS4-vY (or Search for Austin Astronomical Society.)

Redshift—Kurt Baty’s September 11 presentation, “The Antikythera Device,” could not be livestreamed to YouTube because it included copyrighted material from PBS Nova and other sources. However, you can view a short presentation by Kurt for “Brick Fiesta 2017” a Lego convention on “Beyond the Brick” on You- Tube here https://www.youtube.com/watch?v=t1I1kdW3wgE

4 •November 2020 • Sidereal Times THE ALCORNER Your Astronomical League Update

By Dawn Davies, AAS Astronomical League Correspondent (ALCOR)

These are trying times we are in for the obvious reasons and because though we may be near our observing gear, constantly, the skies have not been too accommodating. That being said, there are still things you can do with your time indoors.

Take this time to:

• Catch up on reading the Astronomical League’s quarterly publication, The Reflector. Current and past issues can also be found on the AL’s website. • Complete those observing program logs you keep saying you are going to finish. • Submit a proposal for a new observing program, details and instructions here. • If you are working on your Herschel II, click here to read about upgrades to the list.

As most of you may know, the Astronomical League Convention in Albuquerque has been cancelled. And while we were unable to hold our Messer Marathon last month, rest assured that the first chance for us to meet in person and observe together again at Bad Wolf Ranch will be a night to celebrate. Until then consider working on one of the AL observing programs that does not need clear and dark skies:

• Analemma • Astronomy Before the Scope • Citizen Science • Constellation Hunter – Northern Skies • Dark Sky Advocate • Hydrogen-Alpha Solar • Lunar and Lunar II • Radio Astronomy • Spectroscopy • Sunspotters

Feel free to reach out if you have any questions about all things AL related, and even those that are not. Stay healthy, be well, and as always…

Clear Skies,

Dawn

Sidereal Times • November 2020 • 5

Outreach Report November 2020 Calendar of By Joyce Lynch, Outreach Chair Events

lthough in-person star parties are still on hold, we did a virtual event for the City of Bee Cave on November 5. Terry Phillips, Dawn Davies, Jamie Canfield, 13 Nov 2020 AJim Lynch and I were on a Zoom call with about 60 visitors at one point. General Assembly Meeting Although Jim had some technical difficulties with his camera and Dawn got booted 7:30 PM out of a parking garage at the Domain where she had gone for a better view of the Zoom Video Meeting @ Stay at Home sky, we did manage to do astronomy for over 90 minutes. Terry used Stellarium to talk about the planets in the sky at the moment and the upcoming conjunction of Saturn and Jupiter as well as some winter objects that are starting to be visible. Dawn changed her location and showed Mars and some double stars using her scope and 7 Dec. 2020 phone. There were a lot of questions and positive feedback from visitors, and we Executive Committee Meeting learned some lessons about what to do and what not to do in a virtual event. 7:00 PM - 8:30 PM Joyce Zoom Video Meeting @ Stay at Home

In case you haven’t looked at our website recently, here is the list of astronomy web- sites that are posted as a (poor, admittedly) substitute for going to actual star parties. 11 Dec 2020 Austin Astronomical Society • skymaps.com -- Free monthly sky maps Holiday Party • heavens-above.com -- Location-specific schedules for flyovers of satellites, Hub- 7:30 PM Zoom Video Party ble Space Telescope, International Space Station @ Stay at Home • earthsky.org -- EarthSky Tonight--articles on what to look for in the sky each night • https://apod.nasa.gov/apod/archivepix.html -- Astronomy Picture of the Day • stardate.org -- Current observing information and educational resources produced by UT’s McDonald Observatory • skyandtelescope.com -- Sky and Telescope magazine—interactive star charts, articles on observing, selecting equipment, everything astronomical • pbase.com/missouri_skies/moon_page -- Moon photos • hubblesite.org -- Information about and photos from the Hubble Telescope • twanight.org -- The World At Night photographs and time-lapse videos of the world’s landmarks against celestial attractions • bludja.blogspot.com/2006/06/relative-size-of-planets-stars.html -- See how objects in our solar system compare with distant stars • astrosociety.org -- Astronomy Society of the Pacific—astronomy education

6 •November 2020 • Sidereal Times The International Space Station: 20 Continuously Crewed Years of Operation By David Prosper

id you know that humans permanent crew members to the have been living in the In- station in a Russian Soyuz capsule: Dternational Space Station, NASA astronaut William M. Shep- uninterrupted, for twenty years? Ever herd and Russian cosmonauts since the first crew members docked Sergei Krikalev and Yuri Gidzenk. with the International Space Station Since then, an entire generation (ISS) in November 2000, more than has been born into a world where 240 people have visited this outpost, humans continually live and work representing 19 countries working in space! The pressurized space in- Caption: A complete view of the ISS as of October 4, 2018, taken from the Soyuz capsule of the departing together. They have been busy build- side this modern engineering mar- crew of Expedition 56 from their Soyuz capsule. This ing, upgrading, and maintaining the vel is roughly equal to the volume structure was built by materials launched into orbit by 37 United States Space Shuttle missions and 5 Russian space station - while simultaneously of a Boeing 747, and is sometimes Proton and Soyuz rockets, and assembled and main- engaging in cutting-edge scientific briefly shared by up to 13 individu- tained by 230 spacewalks, with more to come! Credit: NASA/Roscosmos More info: bit.ly/issbasics research. als, though the average number of The first modules that would later crew members is 6. The unique mi- Venus to observers on the ground! make up the ISS were launched crogravity environment of the ISS Its morning and evening passes can into orbit in 1998: the Russian Zarya means that long-term studies can be a treat for stargazers and can even launched via a Proton-K rocket, and be performed on the space station be observed from brightly-lit cities. the US-built Unity module launched that can’t be performed anywhere People all over the world can spot the about a week and a half later by the on Earth in many fields including ISS, and with an orbit only 90 minutes Space Shuttle Endeavour. Subse- space medicine, fluid dynamics, long, sometimes you can spot the quent missions added vital elements biology, meteorology and environ- station multiple times a night. You can and modules to the Space Station mental monitoring, particle phys- find the next ISS pass near you and before it was ready to be inhabited. ics, and astrophysics. Of course, receive alerts at sites like NASA’s Spot And at last, on November 2, 2000, one of the biggest and longest the Station website (spotthestation. Expedition-1 brought the first three experiments on board is research nasa.gov) and stargazing and satellite into the effects of microgravity on tracking apps. the human body itself, absolutely Hundreds of astronauts from all over vital knowledge for future crewed the world have crewed the Interna- exploration into deep space. tional Space Station over the last two Stargazers have also enjoyed the decades, and their work has inspired presence of the ISS as it graces our countless people to look up and pon- skies with bright passes overhead. der humanity’s presence and future This space station is the largest ob- in space. You can find out more about ject humans have yet put into orbit the International Space Station and at 357 feet long, almost the length how living and working on board this of an American football field (if amazing outpost has helped prepare end zones are included). The large us to return to the Moon - and be- solar arrays – 240 feet wide - reflect Caption: The ISS photobombs the Sun in this amazing yond! - at nasa.gov. image taken during the eclipse of August 21, 2017 quite a bit of sunlight, at times from Banner, Wyoming. Photo credit: NASA/Joel making the ISS brighter than Kowsky More info: bit.ly/eclipseiss

This article is distributed by NASA Night Sky Network. The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.org to find local clubs, events, and more!

Sidereal Times • November 2020 • 7 Bad Wolf Ranch – AAS’s Dark Sky Site

In this time of Covid-19 danger, the club has cancelled all member star parties until further notice. For individual viewing nights the club requires physical distancing or wearing of masks when visiting between unrelated groups. Be safe, we value the well–being of our members and their families.

Bad Wolf Ranch? Thanks to AAS members, Alan and Carolina Carruth, our club has the use of Bad Wolf Ranch for member-only star parties, special events like the 50th anniversary of the Apollo landing, AND private observing any night for every member and her guests.

The ranch is located approximately 15 miles NNW of Lampasas and 60 miles from Austin in an open area with only a few ranch houses within several miles. Most importantly, there is a porta-potty that is serviced on a weekly basis.

Although undeveloped there is a ranch building (off limits to AAS) and a small AAS dome with a 12.5-inch scope available to members. The skies are dark - in the rural/dark sky transition zone

Sample SQM readings at 10:30pm on 4/20/2020: Zenith – 21.41 North – 21.53 East – 20.95 South – 21.22 West -21.18

Be prepared • Bring your own power – not available on site • Bring your own water - not available on site • Watch out for cow patties and ants

Bad Wolf Ranch Rules at all Events • No Loud music • No Tampering with fences or gates • No Hunting of any sort • No Activities which materially interfere with owners use and enjoyment of his/her adjacent lands. • No access to owner’s structures • Don’t damage, deface or destroy any property or improvements • AAS members are responsible for closing and locking all gates when leaving • No Discharge of firearms or fireworks

Member Individual Observing

To arrange for private observing contact Alan Carruth for permission: [email protected]

if you do not receive a reply in 24 hours permission is granted

As a reminder, in this time of Covid-19 danger the club requires physical distancing or wearing of masks when visiting between unrelated groups. Be safe, we value the well – being of our members and their families.

Most importantly, enjoy a night under the stars at Bad Wolf Ranch

I always appreciate comments and suggestions after your visit. Many members are working to improve everyone’s experience. Your suggestions are vital. For directions contact: [email protected], or feel free to call or text me at: (512) 577-8340. Tim Brown, Member Services Chair

8 •November 2020 • Sidereal Times A Star Party - at Bad Wolf Ranch ????

Are you interested in a Physically Distanced, Masked When Not at Your Scope, Members-Only Star Party at Bad Wolf Ranch?

This is a note to poll members to gauge the interest, gather comments and suggestions for our return to a night under the stars with our fellow AAS members.

If interest is sufficient the Executive Committee will begin planning for a safe and fun return to Bad Wolf Ranch.

Members Star Party – December 12th – Bad Wolf Ranch

Great Observing December 12th is the perfect date (if the weather gods co-operate) to get back to social observing at Bad Wolf. The Moon rises at 4am and is only a 5.7% crescent. Excitingly, the Geminids shower peaks on the 13th at 1:00am with a possible maximum of 120 meteors/hr. You never know, but this could be a fantastic show.

COVID-19 Precautions Of course, everything is dependent on the state of the Pandemic in December. We will be cautious and in the intertest of everyone’s health, require everyone to follow safety precautions.

Everyone can setup with the friends that are known to you to be safe – your “bubble”. Observing groups will be situated at least 12 feet apart and we will have to limit the total attendance to a safe and legal size.

But this is just a starting point. We will consider and incorporate your comments and suggestions in the final arrangements.

Let us Know It is vital that we hear comments and suggestions for members. It can’t happen without hearing from you. Here are two suggested questions, but feel free to add any comments you like.

1.) Should the club hold a Members Star Party at Bad Wolf Ranch on December 12th? 2.) What special arrangement for Covid-19 safety do you suggest?

Let’s get together for a night of great observing at Bad Wolf Ranch on December 12th.

Sidereal Times • November 2020 • 9 Pedernales Report November 2020 By Gregory Rohde

10 •November 2020 • Sidereal Times Pedernales Report November 2020

Sidereal Times • November 2020 • 11 Pedernalas Report November 2020

12 •November 2020 • Sidereal Times Observing Targets November 2020 By Brian Cuthbertson

outhern November skies even though he did enter such from which the Perseus OB1 drift across extragalactic obvious clusters as the Praesepe association formed. space toward the (M44) and the Pleiades (M45). The two clusters also blue- winter Milky Way. Early The two clusters, NGC 869 shifted, both approaching the SNovember evenings set sail in (h Persei) on the west, and Sun at just over 20 km/sec. Or deep galaxy-rich realms like NGC 884 (CHI Persei) on the are we approaching them? No Aquarius, Pegasus and Cetus. east, combine to present an matter, the result is that the And depending how late you incredibly rich and beautiful Double Cluster will grace our want to stay up, they drift into field. In a 6-inch scope, NGC skies for a long time to come! Eridanus, Taurus, and eventually 869 has two bright stars near reach the shores of the winter its center and appears the more NGC 1023 rating Milky Way at Orion. It’s quite a sharply concentrated of the MEDIUM trip, with more available stops pair. Its brightest central star (h sgalaxy in Perseus than you’ll possibly have time Persei, visual magnitude 6.6), RA 02h 40.4m Dec +39d 3.8’ (2000) for. has a bowl-shaped arc of 5 stars Magnitude 9.3 on its east side. In a 12-inch NGC 869+884 rating scope this arc outlines a nearly Located in Perseus just EASY perfect parabola. east of its north-south border Vdouble cluster in Perseus NGC 884 (CHI Persei) is larger with Andromeda, NGC 1023 is RA 02h 21.0m Dec +57d 08.0’ (2000) but less concentrated than NGC the brightest and most massive Magnitude 3.5 (each) 869. A 6-inch will get you about member of the NGC 1023 50 stars, with a bright knot on galaxy group. This group also Welcome to one of the the SW side. The star count rises includes the famous edge-on all time favorites for amateur to roughly 3 times that in a 12- galaxy NGC 891, as well as observers! The “Double Cluster” inch scope. perhaps a dozen other galaxies. in Perseus, which lies just west Compared to the Pleiades, NGC 1023 is visible even a of the arc of stars known as the which is 75 to 150 million years 2.4-inch refractor, in which Segment of Perseus, is a truly old, both NGC 869 and 884 are it appears as a high surface classic example of a galactic relatively young clusters, at brightness football-shaped spot clusters, or rather, a pair of only 5.6 and 3.2 million years, elongated roughly east-west. them. Their existence was respectively. Distance-wise, You’ll begin to see a distinct known as early as as 150 BC. the two are 7000 light years core and stellar nucleus in Both Hipparchus and Ptolemy away, more or less. They are a 6-inch and larger scopes. were aware of an object there, dominant part of the Perseus NGC 1023 is a highly-inclined, calling it a “cloudy spot” - one OB1 association, whose more bright barred spiral with a of a half dozen or so then luminous members exhibit bulk large conspicuous core region. recognized. But of course the motion away from the galactic It was originally classified as actual nature of the clusters plane. The thought is that these a peculiar galaxy based on wasn’t learned until later, with younger stars formed from a condensation 2.6’ east of the invention of the telescope. molecular gas pushed outward the galaxy’s core which was And oddly enough, Charles by an expanding superbubble, was thought to be a “galaxy Messier did not include the composed of swept up remains fragment”. Consequently Double Cluster in his catalog, of the giant molecular cloud NGC 1023 is designated as

Sidereal Times • November 2020 • 13 Observing Targets November 2020

Arp 135. The fragment is now one of dozens of stars that central black hole. Unlike most recognized as NGC 1023A, a small mark the course of the celestial other spiral galaxies, however, irregular dwarf galaxy that may river. NGC 1300 is not known to have be in the process of being tidally NGC 1300’s claim to fame an active nucleus, indicating disrupted by its larger neighbor. is simple: it’s a nearly perfect either that there is no black hole, NGC 1023A is visible in medium example of a face-on two- or that it is not accreting matter. sized instruments, but can be armed barred spiral galaxy. Keep in mind that galaxy challenging: in a 17.5-inch at Located 70 million light-years magnitudes are total magnitudes, 200x, it’s visible as a wispy plume away, the galaxy spans over and can be deceiving if the off the eastern extension of NGC 100,000 light-years. A close galaxy is spread out over a large 1023’s halo. Sounds a lot like our inspection of deep images such area. In large scopes NGC 1300 is Milky Way’s own Sagittarius dwarf as those taken by the Hubble a very large and very low surface galaxy to me! Space Telescope reveals a brightness beast with a distinct second embedded classic (non- bright core. Low powers show NGC 1300 rating HARD barred) spiral structure 3,300 a bright central bar surrounded galaxy in Eridanus light-years across, centered on by a faint halo. At higher powers RA 03h 19.7m Dec -19d 25.1’ (2000) the galaxy’s nucleus. the 2 spiral arms become more Magnitude 10.4 6.5x4.3’ Only galaxies with large- obvious, with the southern arm scale bars appear to have these brighter and more distinct. The looping constellation of “grand-design” inner disks - a Anyone who gets familiar Eridanus wraps around hundreds spiral within a spiral. Models with NGC 1300, either visually or of galaxies, among which a few suggest that the gas in a bar pictorially, will agree that barred stand out and merit a visit. NGC can be funneled inwards, and spirals don’t get much better 1300 is certainly one of these. You then spiral into the center than this. So now you have a can find it just over 2 degrees due through the grand-design disk, great answer when someone asks north of 4th magnitude 16 Eridani, where it can potentially fuel a you where your favorite bar is!

Employment Opportunity

Canyon of the Eagles is accepting applications for an Astronomer. This position can be permanent part time and/or permanent full time. The Astronomy programs are being expanded to include seven days a week for our guests. We are in the planning stages to upgrade our observatory facility and telescopes.

A prospective astronomer must have knowledge of many aspects of the cosmos, including constellation names and locations, with awareness of significant objects within those areas. This applicant should have a working knowledge of many of the objects in the Messier, NGC and Caldwell catalogues. The applicant must have skills in operating fully automated telescopes and the software that drives them as well as the ability to polar align equatorial mounts.

The primary goal of our astronomy program is to enlighten and entertain our guests. With that in mind, an applicant must have a desire to do public outreach and interact with people in a positive way.

For more information, contact Canyon of the Eagles at: (512-334-2070)

14 •November 2020 • Sidereal Times The Discoveries of Galileo – Part 4: Venus By Ed LaBelle, Psalm 19 Astronomy

the University of Pisa. movement around the Earth. The circles of some objects such as the The Ptolemaic geocentric model was Moon and planets didn’t match up the prevailing belief in the early 1600’s to observations, so Ptolemy came up among the Roman Catholic Church with a mathematical way to align the and European natural philosophers re- movements: deferent and epicycle garding the movement of the celestial circular paths. To explain the frequent- objects: the planets, Sun, Moon, and ly observed retrograde motion of stars all revolved around the Earth. the planets, Ptolemy had them move Ptolemy (100 – 170 AD) was a Greek along a smaller epicycle circle fixed to mathematician, astronomer, and geog- their larger deferent circle that orbited rapher living in Egypt who provided a around the Earth (figure 2). comprehensive treatise on astronomy titled The Almagest. This series of books alileo’s discoveries of Jupiter, was based on Ptolemy’s quarter-cen- sunspots, and the Moon were cov- tury observations and included the ered in parts 1 through 3 of this G known ancient celestial observations series. This article will cover an important recorded from Egypt and Arabia. Ac- discovery that Galileo made in late 1610 cording to the Encyclopedia Britannica, of his observations of Venus. Figure 1 Ptolemy argued that the Earth “is a sta- shows the timeline of Galileo’s discover- tionary sphere at the centre of a vastly ies during 1609 and 1610. larger celestial sphere that revolves at a perfectly uniform rate around Earth, Over the summer of 1609 Galileo refined carrying with it the stars, planets, Sun, his spyglass from about 3x magnification and Moon—thereby causing their daily in June to around 8x by October. During risings and settings.” this time, he also moved from Padua to The Ptolemaic model included a series Florence, Italy after being appointed by of circles along which celestial objects Cosimo II, the Grand Duke of Tuscany, as coursed through during their annual Philosopher and Chief Mathematician of Recall from the Part 2 article on sunspots that Galileo was corresponding with a wealthy Augsburg merchant named Mark Welser in response to sunspot observations by the Jesuit priest, Christopher Scheiner (aka Apelles). Galileo brings up the topic of Venus in his First Letter on Sunspots dated May 1612 and he states that he had discovered that Venus changed shape two years earlier in 1610. Apelles had suggested that sunspots afforded a method for determining whether “Venus and Mercury revolve about the sun or between the earth and the sun.” Galileo wrote, “This is the fact that Venus changes shape precisely as does the moon.” (Discoveries, p. 93). Later in the letter Galileo forcefully

Sidereal Times • November 2020 • 15 The Discoveries of Galileo – Part 4: Venus as when it is most distant, and although leo solidified his belief in the Coper- this difference can be precisely observed nican model in a lengthy letter to the only with the telescope, it is neverthe- Grand Duchess Christina of Tuscany. less quite perceptible to the naked eye.” This letter was subtitled “Concerning (Discoveries, p. 131). the Use of Biblical Quotations in Mat- ters of Science.” Galileo wrote, “Further- The left drawing in figure 4 shows the more, it would be necessary to forbid imagined phases of the Ptolemaic geo- men to look at the heavens, in order centric model of Venus were it to orbit that they might not see Mars and Venus above or below the Sun or between sometimes quite near the earth and the Earth and the Sun. Galileo posited sometimes very distant, the variation that the Ptolemaic model would only being so great that Venus is forty times produce horned or crescent phases and Mars sixty times as large at one time either pointing rightward or leftward. as another. And it would be necessary to asserted, “As a matter of fact nothing else The right drawing in figure 4 shows prevent Venus being seen round at one could be said before the telescope came Galileo’s illustration made during his time and forked at another, with very along to show us that Venus is naturally observation of a full cycle of Venus thin horns; as well as many other sensory and actually dark like the moon, and like moving around the Sun. Starting with observations which can never be recon- the moon has phases.” (Discoveries, p. 95). Venus at position #1, he saw a right- ciled with the Ptolemaic system in any Galileo explained his observations of the ward facing crescent move through way, but are strong arguments for the phases of Venus from his drawings of Ve- phases #3 & 4 where Venus grows Copernican.” (Discoveries, p. 195-196). nus from October 1610 to February 1611 smaller and rounder and finally to Galileo goes on to argue that Coper- as seen in the top panel of figure 3. Ve- #6 the leftward facing crescent. The nicus’ book should not be banned but nus varies from a small perfectly shaped Copernican model below the phase should be viewed in light of the new sphere on the right to a larger semicircu- sketches shows the relative position astronomical evidence being observed lar sphere and then passes into a horned of Venus to the Earth and orbiting nightly. shape on the left which becomes wide around the Sun. These matched well Thus, through observational astrono- and thin as it approaches the Sun. Galil- with what Galileo observed. He con- my in the early 17th century, Galileo eo wrote in the First Letter on Sunspots, cludes in his Third Letter on Sunspots, was able to open new cracks in the “These things leave no room for doubt “The opaqueness of Venus is indubi- foundation of the Ptolemaic model. about the orbit of Venus. With absolute tably proved by the single experience I Next month I will write about Galileo’s necessity we shall conclude, in agreement reported in my first letter; namely, our observations of the Milky Way and sev- with the theories of the Pythagoreans and seeing Venus vary in shape as does the eral large constellations which created of Copernicus, that Venus revolves about moon. This is the only strong argument still more cracks in that foundation. the sun just as do all the other planets.” for proving Venus to revolve about the (Discoveries, p. 95). I also inserted the im- sun; let it suffice us, as it leaves no room ages from Stellarium astronomy software for doubt.” (Discoveries, p. 133). Hence, Ed LaBelle has been a member of AAS since 2010. for the same time frame in 1610 – 1611 using drawings of the phases of Venus He has worked as an engineer in the semiconduc- to confirm how well the software can and inductive reasoning, Galileo “indu- tor industry for 30 years and is the founder of the reach back into time and align to what bitably proved” the Copernican model Psalm 19 Astronomy Society based in Austin. Galileo saw (figure 3, bottom panel). best fit the observational data. Finally, a few years later in 1615, Gali- Galileo used his lengthy observations of the phases of Venus and inductive reasoning to prove that Venus revolved around the Sun and not below it as many believe at the time. He also noted that the apparent diameter of Venus changes over time. In his Third Letter on Sunspots to Welser in December 1612 he noted, “For when the planet is nearest the earth, its diameter is more than six times as great

16 •November 2020 • Sidereal Times Image of the Month November 2020 Congratulations to Satwant Kumar

Cygnus loop - Face of stellar death

Cygnus loop (Sh2-103) is a remnant of a violent cosmic explosion of a star, which was 20 times more massive than the sun. The visible exterior sac of the low-density gas was blasted into space by the dying star before its self-detonation. To me, the eastern veil nebula, a subcomponent of the Cygnus Loop, appears to be face pareidolia. Hence, I am calling it the face of stellar death.

Sidereal Times • November 2020 • 17 Members’ Gallery

by Robert Van Gulick Rosette in SHO patte

by Robert Van Gulick Sculptor_PI Galaxy

18 •November 2020 • Sidereal Times Members’ Gallery

by Steven Farmer Oct 22 Moon Taken with iPhone through Delos 17.3 eyepiece on a 8” Dobsonian.

by Eric Dreher Eastern Veil Nebula NGC6992, the eastern Veil Nebula, taken August 29 and October 10, 2020

Stellarvue SVX102T - Astro-Physics Mach1GTO ASI1600MM Pro - Baader Ha and OIII filters 7.3 hours integration

by Chris Foster by Chris Foster IC1396 in LSHO NGC7822 Nebula in LSHO

Sidereal Times • November 2020 • 19 Treasurer’s Report November 2020 By Patrick McPhee, Treasurer

20 •November 2020 • Sidereal Times EC Minutes September 2020 By Jamie Canfield, Secretary

Austin Astronomical Society

Executive Committee Minutes

September 2020 (Held Aug 31.- Sept 7 was Labor Day Holiday)

Virtual Meeting hosted on Zoom by Terry Phillips, President

Attending: Terry Phillips, Sean Leary, Greg Rhode, Joyce Lynch, Brian Lippincott, Tim Brown, Patrick McPhee, Mike Marotta, Jamie Canfield

Call to order at 7:00 PM. August meeting minutes discussed and approved.

Vice President – Mike Marotta (see report and proposed budget) Contacted Lara Eakins at UT Astronomy who reached out to her students, one of which is now our scheduled speaker for Feb 2021. Also have our own Byron Miller speaking about Astrophotography in Nov, so we’re complete through Feb. Submitted budget and speaker compensation proposal in report.

Treasurer – Patrick McPhee (See Treasurer’s Report) 2020-2021 Proposed Budget presentation and discussion. $7000 coming in & $9000 going out- we’re about $2000 “in the hole’. The long term trend doesn’t seem sustainable. Joyce noticed no entry for AL dues- it’s about $5 per membership. Need to pay attention to the current trend- may need to look at fundraisers for next year. Also asset sales. Brian- we are telescope-rich! We have assets we can sell. *Greg & Brian submit remaining receipts.

Equipment – Brian Lippincott Conex- not much new to talk about, see expenditures in the budget. Got the loaner scopes from Domingo. Got $2100 from Stephen Miller for the Losmandy (brand) system (equatorial mount for astrophotography).

Outreach – Joyce Lynch Talking to the Bee Cave city government, they’re working on getting “Dark Sky Certification” and wanting to have a star party. Looking at online classes/presentations to have something for the International Observe The Moon Night- Sept 26.

Member Services – Tim Brown Hopeful that we could do something in November like a private star party with limited numbers. Discussion about the best way to follow up on membership requests on FB group How to get a better handle on that. Maybe ‘feed’ it to Outreach. Maybe have a “Join” button on the website. Tim working with Terry on this.

Communications – Sean Leary (See Sean’s report) Ongoing website maintenance and improvements. Transferring to another site hosted by Azure. Not much going on otherwise while this work progresses.

Sidereal Times • November 2020 • 21 EC Minutes Continued

Members At Large Greg Conex – chugging along each weekend. Moving the scopes out there will be the final project, after all the other work is done first. About 95% finished with Conex purchases. Also will need to purchase some form of ramp.

Webmaster – Byron Miller Can see the current site “as is” running on new infrastructure here: https://beta.austinastro.org should be much faster. The old web hosting is very slow- upgrade to Wordpress 5.5 failed. Please login to the beta site and poke around! Working on migration to new servers. Even without optimization it’s already much faster. With the database up and running, plan is to finish setting up the forums and then share the URL.

Old Business

Pedernales Falls- Would they support more of us going out to have a sort of shake-down of the equipment, maybe a dozen or more? *Joyce will check with Stephen!

Virtual Meetings- *Need to get approval/sign-off on live streaming from our upcoming presenters. *Mike will be getting an approval from Kurt, after that putting together a kind of “permission packet” for future speakers. Two aspects to the meetings: 1)presentation on Zoom; 2)livestreaming on YouTube. *Terry getting together w/Sean to get recorded meetings transferred to our YouTube account.

New Business EA Astronomy Planning- Terry still working on this, and logistics. Talking about other folks doing this. Hufflepuff Observatory mentioned doing this, *can talk to her about doing a presentation for AAS. *Need to look at what these other people are doing & set up something for our club, so about $1600 to get started with cameras & such.

Converting new FB members to actual AAS members- Dawn added a new question for folks joining the FB group. We haven’t been following up on people who’ve expressed interest in joining (by answering the join question). Also getting emails from people needing help to join online. Joyce is the contact person for the Night Sky Network, for folks looking for Astronomy clubs. *Joyce start tracking this so we can see what’s going on. See if the requesters end up joining AAS. *Sean add a “Join Now” button on the website.

Adjourned about 9:00 PM

Respectfully submitted, Jamie Canfield

22 •November 2020 • Sidereal Times GA Minutes September 2020 By Jamie Canfield, Secretary

Call to order: 7:30 pm Location: Zoom video conference. President Terry Phillips presiding

Approximately 40 members attended. Quorum does not apply to remote meeting. No items voted on.

Minutes for the August 2020 meeting approved.

Officer Reports: Mike Marotta (Vice President): We now have Dr. Moriba Jah from the Department of Aerospace Engineering and Engineering Mechanics at UT on the lineup.He describes himself as an “Astrodynamicist” who studies the motion of objects in space. He’ll be speaking this coming Spring about “Space Junk”. GA Speaker lineup: October 9 – Stuart Parkerson, Astronomy Technology Today November – Byron Miller, Astrophotography December – Newtonmas Party! January – Tom Field, Spectroscopy February – Ronan Kerr, Young Stars in our Neighborhood

Patrick McPhee (Treasurer): Discussion about new proposed budget. Pat will send the budget out to all members via Wildapricot.

Brian Lippincott (Equipment): Continuing work on Conex, going out every Saturday. Getting rid of some equipment not usable for loaner program. Finishing the Coronado Personal Solar Telescope for daytime observing. . Sean (Communications) Maintaining the website, working with Brian on inventory. Working on website limitations with Byron.

Tim Brown (Member Services): Greg talked to John Alves at Pedernales Falls and he said it was fine with them to have a small party, but limit 10. We could get a waiver for more but they must submit a request to the county judge, which process he has already begun for us! Will continue discussion about keeping social distance and logisitics.

Joyce Lynch (Outreach): Not much going on – sooner or later we’ll be getting together! The International Observe The Moon Night is coming up on September 26th.

Regular Features: Dawn (ALCOR): October is the first annual Hill Country Night Sky Month. Among the events are virtual Star Parties conducted by the Travis County Friends of the Night Sky, on October 10th from Wild Basin Wilderness Preserve and Oct 24th from McKinney Falls State Park (Dawn is one of the speakers/presenters) More details forthcoming. More virtual astronomy- the Keck Observatory website, with dozens of “Cosmic Videos” of Astronomy Talks by guest scientists from around the world, adding a new one each month. AAVSO free webinars Saturdays through Oct 3rd. Coming up, “Instrumentation & Equipment”, Parts 1 and 2. AL announced new Space Science badges for Gril Scouts.

Brian (What’s Up in Astronomy): Dark matter, WIMPs, and MACHOs, from Astrobites website and JPL. Also from JPL- “The Moon is Rusting”- Evidence of hematite that normally requires oxygen and water. And the monthly “What’s Up” video, for September.

Main Presentation: Kurt Baty, “The Antikythera Device”

Adjourned at approximately 9:15p

Sidereal Times • November 2020 • 23 Membership Cards Now in Your Profiles

At last, Wild Apricot, our membership database vendor, has made available to its customers membership card templates. Now, under your AAS membership profile you will see a mockup of a card with your name, Membership ID and membership expiration date. You are offered two options for displaying your card: one which is suitable for displaying from a smartphone, and another printable PDF which you can cut and laminate to your heart’s delight.

NIGHT SKY NETWORK

The Night Sky Network is a nationwide coalition of amateur astronomy clubs bringing the science, technology, and inspiration of NASA’s missions to the general public. AAS members can register with NSN and receive the NSN newsletter and email about upcoming webinars and any additional information or announcements created by the NSN for members. They will be able to search for resources, view all of the toolkits and the files, and access the downloads in each kit. If you are interested in registering, here is the procedure. Go to https://nightsky.jpl.nasa.gov/index.cfm Enter your zip code in the upper right box for CURRENT LOCATION. Scroll down to CLUBS NEAR YOU and click on AAS. Click on Register in the toolbar on our page. Fill out the form and submit. Your form will be sent to the club for approval.

If you have any questions, email [email protected]

24 •November 2020 • Sidereal Times Joining AAS or Renewing Membership

To join or renew your membership to AAS, please visit: http://austinastro.org/index.php/why- should-you-be-a-member/ There are six membership levels to choose from:

Household Bundle (up to 6 members) $40.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For members of a household living at the same address.

Household With Senior (up to 6 members) $28.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For members of a household living at the same address and at least one member is over 65 years of age.

Junior $15.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For members up to age 18.

Students $15.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For members age 18 and older.

Regular $25.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For individual members.

Seniors $15.00 (USD) Renewal: Every one year, starting from join date No recurring payments. For members 65 years of age or older.

Visit Dawn Davies’ Earthbound Astronomer website at https://www.earthboundastronomer. com/

Amy Jackson’s website is http://www.starryskyaustin.com/. Learn more about her children’s book about astronomy at http://www.starryskyaustin.com/childrens-book-project/

Rob Pettengill’s site can be found at http://astronomy.robpettengill.org/. Rob’s material shared per CC BY-NC-SA 4.0 license.

Celestial Teapot’s product catalog can be found at http://messierplanisphere.com/

Joseph Macry writes a weekly column for Manor Community News: “This Week in Astronomy”. You can read the online edition here: http://manorcommunitynews.com/

Sidereal Times • November 2020 • 25 Officers of The Society 2020-2021

President Terry Phillips [email protected] Vice-President Michael Marotta [email protected] Secretary Jamie Canfield [email protected] Treasurer Pat McPhee [email protected] Communications Chair Sean Leary [email protected] Outreach Chair Joyce Lynch [email protected] Equipment Chair Brian Lippincott [email protected] Member Services Chair Tim Brown [email protected] Member-at-Large Domingo Rochin [email protected] Member-at-Large Greg Rohde [email protected] Member-at-Large -vacant [email protected] Member-at-Large -vacant [email protected] Member-at-Large -vacant [email protected] Member-at-Large -vacant [email protected] Parliamentarian* Ron Carman [email protected] ALCor (Astronomical League)* Dawn Davies [email protected] IDA Rep (Dark Skies)* John Cassidy [email protected] Newsletter Editor* Nathan Morgan [email protected] Webmaster* Byron Miller [email protected] * designates appointed position

26 •November 2020 • Sidereal Times