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Home , Jo Davidson, New Moon, Planetshine

November 2020 The Monthly Newsletter of the Bays Mountain Club

More on Edited by Adam Thanz this image. See FN1 Chapter 1 Cosmic Reflections

William Troxel - BMAC Chair

More on this image. See FN2 William Troxel

More on Cosmic Reflections this image. See FN3

Greetings fellow BMACers! November is here already and of see being offered at the BMAC meetings? What subjects? A course it is only two until Christmas. 2020 has been a series? Activities? Games? Please let me know. very different year for the club. We, as a club, have had to work November's meeting will be hosted by Shawn Beamish. Shawn with some very different ways of meeting and communicating has many times during show & tell shared his robots and a little with each other. I personally miss being able to see each of you bit of what they can do. November’s meeting will feature him and in person at Bays Mountain each . I wish I could be his robots. Shawn will do a brief overview, including a little bit of reporting that we are able to start meeting again, however that is what area he enjoys and focuses on. After that he hopes he will not possible yet. We will be able to meet again at some point in be able to open a link to the robots so each of us will be able to the future. Until that time, this is the club's new normal. control them remotely. It will give us a chance to see what it First, let me thank Brandon for closing out the presentation could be like to control a robot on a distant like the series on Personal Observatories. I hope that all the speakers planetary scientists do. Hope you can sign on and be a part of helped you understand the process you need to go through to what I think will be a fun meeting. As part of the November get one of your own observatories started. Should you find Meeting, I will be having random questions running during the yourself needing additional information, I am sure any of the meeting. Our subjects will be and Meteors so get out your speakers will be happy to answer your questions. All you have to astronomy books, connect with your favorite astronomy teachers do is reach out to them. and be ready to answer the questions. Once the questions close out, I will share the results with you. I will also put the full I have the programs set through December and I encourage you questions and responses in the December newsletter. to check out the web page for the speakers and dates of the online meetings. I want to start talking about going forward for a Before I close this month, I wanted to remind each of you to bit. I need your help. What type of programs would you like to keep working on the astronomy photos that you would want to

Bays Mountain Astronomy Club Newsletter November 2020 3 share as part of the program in December 2020. I will give you more details next month. We have had some really nice evening skies so hopefully you have been able to get out and get some shots.

In closing, I want to encourage you to continue to stay safe. No one knows what "Normal" will look like when the global pandemic is under control. I still remain 100% behind the idea that we, the members of Bays Mountain Astronomy Club, will get through this together. Our club will have to adjust to whatever normal is and we will. Until that arrives when we can meet together, get out and enjoy the sky and practice with your equipment. Until next time, this is your Chairman William Troxel wishing you…

Clear Skies.

4 Bays Mountain Astronomy Club Newsletter November 2020 Chapter 2 BMAC Notes

More on this image. See FN4 More on BMAC News this image. See FN3

Mars! This image is from BMACer Dan Mullen. He used a ZWO CMOS video camera along with some good amount of magnification and frame stacking processing.

Bays Mountain Astronomy Club Newsletter November 2020 6 M31 - The Andromeda Galaxy The yellowish interior reveals older stars shifting to redder hues. The bluish outer rim is caused by newly forming hot stars. Dust lanes can be seen, especially against the central bulge. A warping of the spiral arm disk can bee seen. Image 2.14°x3.22° Image by Adam Thanz

7 Bays Mountain Astronomy Club Newsletter November 2020 Chapter 3 Celestial Happenings

Jason Dorfman

More on this image. See FN5 Jason Dorfman

More on Celestial Happenings this image. See FN3

We should all feel a bit refreshed as November begins, having with Jupiter closing the gap between the two giant worlds. gained an hour of sleep the previous night. Daylight Saving Time Jupiter sets just after 10 p.m. and about 25 minutes later ends at 2 a.m. on the morning of the 1st, so be sure to set your at the start of November, so your best observations of these two clocks back an hour. The night hours continue to lengthen and gas giants with their many will occur just after now arrive earlier with the setting at 5:32 p.m. as November while they are at their highest elevations. As the month comes to begins. By month's end, the Sun will set almost 20 minutes a close, you'll find the pair above the SW horizon an hour after earlier. Sunrise comes at 6:54 a.m. on the 1st and will shift to sunset with Saturn sitting higher at 23° and Jupiter now just 2.3° 7:23 a.m. on the 30th. away to the west at 21°.

This month, we’ll be able to observe all the in the Solar Jupiter begins the month at a still bright magnitude of -2.2 and System. As twilight is beginning to fade and the brighter stars are will dim by just 0.2 magnitudes by month's end. Optical just turning on, you should be able to make out Jupiter, Saturn instruments will reveal the banded disk spanning 37", which will and Mars spread across the southern sky from the southwest to decrease slightly to 34" during the month as we continue to pull the southeast. The planetary highlights will be our focus this away from Jupiter in our faster orbit. month. Saturn shines more dimly at magnitude +0.6. Though further Planets away, Saturn is still an impressive sight with the planet's disk An hour after sunset on the 1st of November, look southward spanning 16" and the ring plane extending to 38", rivaling that of and you'll find Saturn and Jupiter straddling an altitude of 30°. Jupiter. The north pole of Saturn is currently tilted towards us by The two are 5° apart with Jupiter to the west outshining Saturn 22°. This will decrease over the next few years as we head by almost two magnitudes. Both are found east of the Teapot in towards another ring plane crossing in 2025. Sagittarius and are moving slowly in a normal eastward direction

Bays Mountain Astronomy Club Newsletter November 2020 9 Now, let's turn our gaze to the SE for the most distant planet in Mars is located just south of 4th-magnitude epsilon Pisces (ε the , Neptune. On the 1st, you can find this icy giant Psc). It will move from 3° to a little over 1° away from the star over in the northeast section of Aquarius, sitting about 38° above the the month as its motion changes direction. The disk of Mars will southeast horizon an hour and a half after sunset. It will reach its appear 20" in diameter and will decrease to 15" as we reach the highest elevation of 47° at 9 p.m. Neptune's slow retrograde 30th. With that in mind and even though we're now past motion will decrease over the month until it comes to a standstill opposition, you can still enjoy some impressive views of the Red on the 29th. As December begins, it will start to move in a Planet during the first half of November. The magnitude of Mars normally eastward direction. will lessen by a magnitude to -1.1 as we see the phase change from 98% to 92% over the month. At a dim magnitude of +7.9, you'll need a telescope and a star chart to locate Neptune. Start by centering 4th-magnitude Phi Now let’s take a look at another distant icy world, Uranus. This ice Aquarii (Φ Aqu) in your eyepiece and then shift eastward and a giant reached opposition on Halloween, and therefore is in a little north to find bluish Neptune less than a degree away. There prime observing position as November begins. Though a bit are two 6th-magnitude stars located about twice this distance brighter at magnitude +5.7 than more distant Neptune, Uranus further east that form a small triangle with Phi Aqu. Neptune is currently resides in a rather sparse region of sky in the located in the middle of this triangle and appears as a small, constellation of Aries, the ram. On the 1st, an hour and a half after bluish disk spanning just 2". sundown, Uranus sits just under 25° in altitude above the horizon due east and climbs to its highest elevation due south just after Up next on our planetary journey is last month's "star," the Red midnight. If you start at Hamal, the bright star in Aries, Uranus is Planet - Mars. On the 1st, look to the east an hour after sunset located about 10.5° to the southeast. Without any other bright and you can't miss the bright, reddish point of light floating stars nearby to help guide you, your star-hopping abilities will be almost 25° above the horizon. At magnitude -2.1, it appears as put to the test. If you're successful, you'll find a bluish-green gem bright as Jupiter. Mars continues its retrograde motion in Pisces spanning 4" in diameter as your reward. until the middle of the month. It will appear to stand still on the 15th and then begin moving in an eastward direction for the rest That should give our evening observers quite a lot to observe, for of the month. the remaining planetary highlights we must shift our attention to the early morning skies. Rising shortly after 4 a.m. is our sister

10 Bays Mountain Astronomy Club Newsletter November 2020 world, . An hour before sunrise on the 1st, you’ll find the look to the left about 4° for . This small, rocky world will planet reaching an elevation of 20° above the ESE horizon. At a appear as a thin spanning about 9” in diameter. brilliant magnitude -4.0, it will stand out clearly in the predawn Mercury will rise a bit higher each morning as it continues to sky. Venus is in the constellation of Virgo and starts out near her increase its apparent separation from the Sun until the 10th when left shoulder. It will move quickly eastward over the month down it reaches its greatest western elongation 19° from the Sun. It will through Virgo to her feet. On the 27th, Venus will cross into Libra. then stand 10° high in the ESE 45 minutes before sunup. Having Venus passed through its greatest elongation to the west back in moved a bit further away from , we’ll see a slightly smaller August and has been slowly heading back towards the Sun since disk spanning 7”. The magnitude, however, will be almost two then. A magnified view will reveal the disk of the planet spanning magnitudes brighter as more of the sunlit side is facing towards 13” and looking very gibbous at 81.5% illuminated. As it us. At magnitude -0.6, Mercury will appear slightly gibbous at continues its motion during the month towards the far side of the 58% lit. After the 10th, Mercury will begin moving back in the Sun, more of the sunlit side of Venus will be directed at Earth. By direction of the Sun. As we begin the 3rd of November, month's end, when Venus sits 15° high just as the sky is you’ll be competing once again with the brightening morning beginning to brighten, you’ll see a slightly smaller disk of 12” and twilight for a glimpse of this swift world. a more gibbous phase at 89% illumination. Luna If you’ve been keeping track, you’ll know that there is only one November begins with a nearly full waning gibbous since planet left to discuss. Mercury is emerging from the bright the occurred the previous day. Look to the morning morning twilight to make a brief appearance in our predawn skies skies on the 12th and 13th as a waning crescent Moon passes by this month. You can start looking on the morning of the 2nd when Venus and Mercury. A thin crescent floats about 6.5° above Venus Mercury and Spica will rise together in the east. The two, on the 12th and just 5° above Mercury the following morning. separated by about 4°, will look like a matched pair as Mercury’s is on the 15th. In the second half of the month, the brightness equals that of +0.9 magnitude Spica. You’ll need a Moon will return to our evening skies. A thin waxing crescent will clear view of the eastern horizon, as the two will reach just 5° in pass by Jupiter and Saturn on the 18th and 19th of November. altitude 45 minutes before sunrise. From brilliant Venus, turn your Look to Mars in the east on the 25th and you’ll find a gibbous gaze about 18° downward and slightly to the left for Spica, then Moon 5° to the lower right of the Red Planet. On the following

11 Bays Mountain Astronomy Club Newsletter November 2020 day, the Moon will reach apogee at a distance of 252,211 miles from Earth. And, just like October, the month will end with the Full Moon rising as the evening begins.

Leonids Meteor Shower The Leonids, active between November 6th and 30th, are one of the more prominent meteor events for the fall. This is not because of a high number of events, the predicted rate is only about 15 per hour, but instead is due to many of these events often being bright meteors with a high percentage of persistent trains. The peak will occur on the evening of the 16th/17th. The Moon that night will be just two days old and a very thin waxing crescent, setting well before the prime viewing hours, which occur between 3 a.m. and 6 a.m. This should provide us with some wonderful viewing conditions for any bright meteors. Just find a good, dark location where you can see a large part of the sky, sit back and enjoy.

That’s all for this month. Be sure to bundle up as the temperatures are dropping and get out there and observe.

12 Bays Mountain Astronomy Club Newsletter November 2020 Chapter 4 The Queen Speaks Robin Byrne Robin Byrne

More on Happy Birthday this image. See FN3

This month marks the birthday of a man who helped us to find In 1914, Shapley joined the staff at Mount Wilson Observatory in our place in the Universe. Pasadena, California. He used the 60” reflector to study the distribution of globular clusters in the Milky Way. He discovered Harlow Shapley was born November 2, 1885 in Nashville, that of the 100 known clusters, almost one third are found in the Missouri. He stayed in school up to the 5th grade, but had to direction of Sagittarius. Within the clusters, Shapley could leave to help out on his family’s farm. As a teenager, Shapley got distinguish individual stars, including Cepheid variables. Shapley a job as a journalist in Chanute, Kansas. Shapley wanted to go to used Henrietta Leavitt’s result that the period of variability of a the University of Missouri to major in journalism, but the Cepheid is related to its intrinsic brightness to determine the journalism school was a year away from opening. So Shapley distance to each of the globular clusters. Plotting the positions of looked in the school’s catalog to find an alternative. Starting in the globulars in three dimensions, Shapley discovered that they the A’s, he couldn’t pronounce archaeology, so he went to the were arranged in a roughly spherical distribution. Shapley figured next choice and ended up majoring in astronomy. that the center of this spherical distribution should correspond to Much of Shapley’s work was concerned with properties of stars. the center of the Milky Way. From this he calculated that the In 1911, Shapley determined the size of stars by using the light Solar System was 50,000 lightyears from the center of the galaxy curves of eclipsing binary stars. The technique he developed (this number was later revised to 26,000 lightyears). This was the remained standard procedure for over 30 years. Shapley also first proof that the Sun was not at the center of the galaxy. used the light curves of Cepheid variable stars to prove that they Having discovered the amazing size of our Milky Way, Shapley were not eclipsing binaries. He then was the first to propose that concluded that the Milky Way encompassed the entire Universe. they were instead pulsating stars. This led to the work done by This led to a famous debate in 1920 between Shapley and Heber Henrietta Leavitt. Curtis. Curtis believed that there were other galaxies beyond the

Bays Mountain Astronomy Club Newsletter November 2020 14 Franklin D. Roosevelt with a group of supporters from the Independent Voters Committee of the Arts and Sciences for Roosevelt. Chortling with the President are from left: , Hannah Dorner, Jo Davidson, Jan Kiepura, , and Dr. Harlow Shapley. Image and caption from Life magazine, Volume 17, Number 16 (page 40). October 16, 1944. Photograph by George Skadding.

15 Bays Mountain Astronomy Club Newsletter November 2020 Milky Way. It took Edwin Hubble to prove that Curtis was right. methods” that made “civic cowards of many citizens.” In a clear rebuke toward the HUAC, a few after his testimony, the In 1921, Shapley took over as the Director of the Harvard College American Association for the Advancement of Sciences named Observatory after the death of Edward Pickering. Shapley Shapley its new President. continued Pickering’s tradition of hiring women to serve as computers for the observatory, but also as research scientists. Harlow Shapley died October 20, 1972 just prior to his 87th One of those women, Cecelia Payne-Gaposchkin, earned her birthday. He was survived by his wife, Martha, one daughter and doctorate in astronomy using the research she conducted while four sons. working at the observatory. Shapley would remain in the Harlow Shapley may not be one of the more famous names Director’s position until 1952. among astronomers, but his work on the structure of the Milky Shapley was inclined towards activism, both to promote science, Way was a major turning point in our understanding of where we but also social issues. During the rise of Naziism, Shapley did reside in the Universe. So as we look at the globular clusters in what he could to assist fellow scientists to flee Europe and come the direction of Sagittarius, we can thank Harlow Shapley for the to the United States. In the 1940’s he worked alongside other fact that we know we are looking towards the center of our scientists to help establish the National Science Foundation. He galaxy. lobbied for science to be included in a new organization being developed at the United Nations, which ultimately became known References: as UNESCO (United Nations Educational, Scientific, and Cultural The New Encyclopaedia Britannica, 1995

Organization). Because of his membership in the Independent Astronomy & Space, From the Big Bang to the Big Crunch by Citizens Committee of the Arts, Sciences and Professions Phillis Engelbert, 1997 (ICCASP), which supported a variety of New Deal initiatives, as well as world peace, Shapley was brought before the House Un- Wikipedia - Harlow Shapley American Activities Committee (HUAC) in 1946. Shapley, https://en.wikipedia.org/wiki/Harlow_Shapley disgusted by the entire process, treated the committee with so much disrespect that he was almost charged with contempt of Congress. He accused the committee of using “Gestapo

16 Bays Mountain Astronomy Club Newsletter November 2020 Chapter 5 Space Place

More on this image. See FN6 David Prosper

The International Space Station: 20 Continuously More on this image. Crewed Years of Operation See FN3

Did you know that humans have been living in the International individuals, though the average number of crew members is six. Space Station, uninterrupted, for twenty years? Ever since the The unique microgravity environment of the ISS means that long- first crew members docked with the International Space Station term studies can be performed on the space station that can’t be (ISS) in November 2000, more than 240 people have visited this performed anywhere on Earth in many fields including space outpost, representing 19 countries working together. They have medicine, fluid dynamics, biology, meteorology and been busy building, upgrading, and maintaining the space environmental monitoring, particle physics and astrophysics. Of station - while simultaneously engaging in cutting-edge scientific course, one of the biggest and longest experiments on board is research. research into the effects of microgravity on the human body itself, absolutely vital knowledge for future crewed exploration The first modules that would later make up the ISS were into deep space. launched into orbit in 1998: the Russian Zarya launched via a Proton-K rocket, and the US-built Unity module launched about Stargazers have also enjoyed the presence of the ISS as it a week and a half later by the Space Shuttle Endeavour. graces our skies with bright passes overhead. This space station Subsequent missions added vital elements and modules to the is the largest object humans have yet put into orbit at 357 feet Space Station before it was ready to be inhabited. And at last, on long, almost the length of an American football field (if end zones November 2, 2000, Expedition-1 brought the first three are included). The large solar arrays – 240 feet wide - reflect permanent crew members to the station in a Russian Soyuz quite a bit of , at times making the ISS brighter than capsule: NASA astronaut William M. Shepherd and Russian Venus to observers on the ground! Its morning and evening cosmonauts Sergei Krikalev and Yuri Gidzenk. Since then, an passes can be a treat for stargazers and can even be observed entire generation has been born into a world where humans from brightly-lit cities. People all over the world can spot the ISS. continually live and work in space! The pressurized space inside With an orbit only 90 minutes long, sometimes you can spot the this modern engineering marvel is roughly equal to the volume of station multiple times a night. You can find the next ISS pass a Boeing 747, and is sometimes briefly shared by up to 13 near you and receive alerts at sites like NASA’s Spot the Station

Bays Mountain Astronomy Club Newsletter November 2020 18 More on this image. See FN8

19 Bays Mountain Astronomy Club Newsletter November 2020 More on this image. See FN9

20 Bays Mountain Astronomy Club Newsletter November 2020 website (https://spotthestation.nasa.gov) and stargazing and satellite tracking apps.

Hundreds of astronauts from all over the world have crewed the International Space Station over the last two decades, and their work has inspired countless people to look up and ponder humanity's presence and future in space. You can find out more about the International Space Station and how living and working on board this amazing outpost has helped prepare us to return to the Moon - and beyond! - at https://nasa.gov.

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 https:// nightsky.jpl.nasa.gov to find local clubs, events, and more!

21 Bays Mountain Astronomy Club Newsletter November 2020 Chapter 6 BMAC and more

More on this image. See FN7 More on BMAC Calendar and more this image. See FN3

Date Time Location Notes

BMAC Meetings

BMACer Shawn Beamish will present: Robots: How I Got Interested in Them and What Can Be Done with Friday, November 6, 2020 7 p Via Zoom Them. Shawn will give a brief overview on robots, how he constructs them and then hopefully open up his system for members to be able to remotely control some of his robots.

Friday, December 4, 2020 7 p Via Zoom "Member Astrophotography Show & Tell.” BMACers will share up to five photos/art with each other.

SunWatch

Every Saturday & Sunday Cancelled until further notice. View the Sun safely with a white-light view if clear.; Free. March - October

StarWatch

October 3, 10, 2020 7:30 p

Cancelled until further notice. View the night sky with large telescopes. If poor weather, an alternate live tour October 17, 24, 31, 2020 7 p of the night sky will be held in the planetarium theater.; Free. If you are a club member and have completed the Park volunteer program, you are welcome to help out with this public program. Please show up at least 30 minutes prior to the official start time. November 7, 14, 21, 28, 2020 6 p

Bays Mountain Astronomy Club Newsletter November 2020 23 Bays Mountain Astronomy Club Regular Contributors:

853 Bays Mountain Park Road William Troxel

Kingsport, TN 37650 William is the current chair of the club. He enjoys everything to do with astronomy, (423) 229-9447 including sharing this exciting and interesting hobby with anyone that will www.BaysMountain.com listen! He has been a member since 2010. [email protected] Robin Byrne

Robin has been writing the science history column since 1992 and was chair in 1997. She is an Associate Professor of Annual Dues: Astronomy & Physics at Northeast State Community College (NSCC). Dues are supplemented by the Bays Mountain Park Association and volunteerism by the club. As such, our dues can be kept at a very low cost. Jason Dorfman $16 /person/year Jason works as a planetarium creative and $6 /additional family member technical genius at Bays Mountain Park. He has been a member since 2006. Note: if you are a Park Association member (which incurs an additional fee), then a 50% reduction in BMAC dues are applied. Adam Thanz

The club’s website can be found here: Adam has been the Editor for all but a number of months since 1992. He is the https://www.baysmountain.com/astronomy/astronomy- Planetarium Director at Bays Mountain club/#newsletters Park as well as an astronomy adjunct for NSCC.

Bays Mountain Astronomy Club Newsletter November 2020 24 More on Footnotes this image. See FN3

miles across) orbits outside the rings on the right of the image. The small moon Atlas (30 Footnotes: kilometers, 19 miles across) orbits inside the thin F ring on the right of the image. The brightnesses of all the moons, relative to the planet, have been enhanced between 30 and 60 1. The Rite of Spring times to make them more easily visible. Other bright specks are background stars. Spokes -- ghostly radial markings on the B ring -- are visible on the right of the image. Of the countless Saturn has seen since the birth of the solar system, this one, captured here in a mosaic of light and dark, is the first witnessed up close by an emissary from This view looks toward the northern side of the rings from about 20 degrees above the ring plane. Earth … none other than our faithful robotic explorer, Cassini. The images were taken on Aug. 12, 2009, beginning about 1.25 days after exact , using Seen from our planet, the view of Saturn’s rings during equinox is extremely foreshortened and the red, green and blue spectral filters of the wide angle camera and were combined to create this limited. But in orbit around Saturn, Cassini had no such problems. From 20 degrees above the natural color view. The images were obtained at a distance of approximately 847,000 kilometers ring plane, Cassini’s wide angle camera shot 75 exposures in succession for this mosaic showing (526,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 74 degrees. Saturn, its rings, and a few of its moons a day and a half after exact Saturn equinox, when the Image scale is 50 kilometers (31 miles) per pixel. sun’s disk was exactly overhead at the planet’s equator. The Cassini-Huygens mission is a cooperative project of NASA, the and The novel illumination geometry that accompanies equinox lowers the sun’s angle to the ring the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of plane, significantly darkens the rings, and causes out-of-plane structures to look anomalously Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, bright and to cast shadows across the rings. These scenes are possible only during the few Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed months before and after Saturn’s equinox which occurs only once in about 15 Earth years. Before and assembled at JPL. The imaging operations center is based at the Space Science Institute in and after equinox, Cassini’s cameras have spotted not only the predictable shadows of some of Boulder, Colo. Saturn’s moons (see PIA11657), but also the shadows of newly revealed vertical structures in the For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The rings themselves (see PIA11665). Cassini imaging team homepage is at http://ciclops.org. Also at equinox, the shadows of the planet’s expansive rings are compressed into a single, Image Credit: NASA/JPL/Space Science Institute narrow band cast onto the planet as seen in this mosaic. (For an earlier view of the rings’ wide shadows draped high on the northern hemisphere, see PIA09793.) 2. Leo Rising The images comprising the mosaic, taken over about eight hours, were extensively processed before being joined together. First, each was re-projected into the same viewing geometry and A sky filled with stars and a thin veil of clouds. then digitally processed to make the image “joints” seamless and to remove lens flares, radially Image by Adam Thanz extended bright artifacts resulting from light being scattered within the camera optics. At this time so close to equinox, illumination of the rings by sunlight reflected off the planet vastly 3. The Cat's Eye Nebula, one of the first planetary nebulae discovered, also has one of the most dominates any meager sunlight falling on the rings. Hence, the half of the rings on the left complex forms known to this kind of nebula. Eleven rings, or shells, of gas make up the Cat's illuminated by is, before processing, much brighter than the half of the rings on the Eye. right. On the right, it is only the vertically extended parts of the rings that catch any substantial sunlight. Credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA) With no enhancement, the rings would be essentially invisible in this mosaic. To improve their Acknowledgment: R. Corradi (Isaac Newton Group of Telescopes, Spain) and Z. Tsvetanov visibility, the dark (right) half of the rings has been brightened relative to the brighter (left) half by a (NASA) factor of three, and then the whole ring system has been brightened by a factor of 20 relative to the planet. So the dark half of the rings is 60 times brighter, and the bright half 20 times brighter, 4. Jupiter & Ganymede than they would have appeared if the entire system, planet included, could have been captured in a single image. NASA's Hubble Space Telescope has caught Jupiter's moon Ganymede playing a game of "peek- a-boo." In this crisp Hubble image, Ganymede is shown just before it ducks behind the giant The moon Janus (179 kilometers, 111 miles across) is on the lower left of this image. Epimetheus planet. (113 kilometers, 70 miles across) appears near the middle bottom. (81 kilometers, 50

Bays Mountain Astronomy Club Newsletter November 2020 25 Ganymede completes an orbit around Jupiter every seven days. Because Ganymede's orbit is Hubble couldn't directly view the planets, but instead employed a powerful search technique tilted nearly edge-on to Earth, it routinely can be seen passing in front of and disappearing behind where the telescope measures the slight dimming of a star due to the passage of a planet in front its giant host, only to reemerge later. of it, an event called a transit. The planet would have to be a bit larger than Jupiter to block Composed of rock and ice, Ganymede is the largest moon in our solar system. It is even larger enough light — about one percent — to be measurable by Hubble; Earth-like planets are too small. than the planet Mercury. But Ganymede looks like a dirty snowball next to Jupiter, the largest However, an outside observer would have to watch our Sun for as long as 12 years before ever planet in our solar system. Jupiter is so big that only part of its Southern Hemisphere can be seen having a chance of seeing Jupiter briefly transit the Sun's face. The Hubble observation was in this image. capable of only catching those planetary transits that happen every few days. This would happen if Hubble's view is so sharp that astronomers can see features on Ganymede's surface, most the planet were in an orbit less than 1/20 Earth's distance from the Sun, placing it even closer to notably the white impact crater, Tros, and its system of rays, bright streaks of material blasted from the star than the scorched planet Mercury — hence the name "hot Jupiter." the crater. Tros and its are roughly the width of Arizona. Why expect to find such a weird planet in the first place? The image also shows Jupiter's Great Red Spot, the large eye-shaped feature at upper left. A Based on radial-velocity surveys from ground-based telescopes, which measure the slight wobble storm the size of two , the Great Red Spot has been raging for more than 300 years. in a star due to the small tug of an unseen companion, astronomers have found nine hot Jupiters Hubble's sharp view of the gas giant planet also reveals the texture of the clouds in the Jovian in our local stellar neighborhood. Statistically this means one percent of all stars should have such atmosphere as well as various other storms and vortices. planets. It's estimated that the orbits of 10 percent of these planets are tilted edge-on to Earth and Astronomers use these images to study Jupiter's upper atmosphere. As Ganymede passes behind so transit the face of their star. the giant planet, it reflects sunlight, which then passes through Jupiter's atmosphere. Imprinted on In 1999, the first observation of a transiting planet was made by ground-based telescopes. The that light is information about the gas giant's atmosphere, which yields clues about the properties planet, with a 3.5-day period, had previously been detected by radial-velocity surveys, but this was of Jupiter's high-altitude haze above the cloud tops. a unique, independent confirmation. In a separate program to study a planet in these revealing This color image was made from three images taken on November 9, 2007, with the Wide Field circumstances, Ron Gilliland (STScI) and lead investigator Tim Brown (National Center for Planetary Camera 2 in red, green, and blue filters. The image shows Jupiter and Ganymede in Atmospheric Research, Boulder, CO) demonstrated Hubble's exquisite ability to do precise close to natural colors. photometry — the measurement of brightness and brightness changes in a star's light — by also looking at the planet. The Hubble data were so good they could look for evidence of rings or Earth- Credit: NASA, ESA, and E. Karkoschka (University of Arizona) sized moons, if they existed. But to discover new planets by transits, Gilliland had to crowd a lot of stars into Hubble's narrow 5. 47 Tucanae field of view. The ideal target was the magnificent southern globular star cluster 47 Tucanae, one of In the first attempt to systematically search for "extrasolar" planets far beyond our local stellar the closest clusters to Earth. Within a single Hubble picture Gilliland could observe 35,000 stars at neighborhood, astronomers probed the heart of a distant globular star cluster and were surprised once. Like making a time-lapse movie, he had to take sequential snapshots of the cluster, looking to come up with a score of "zero". for a telltale dimming of a star and recording any light curve that would be the true signature of a planet. To the fascination and puzzlement of planet-searching astronomers, the results offer a sobering counterpoint to the flurry of planet discoveries announced over the previous months. Based on statistics from a sampling of planets in our local stellar neighborhood, Gilliland and his co-investigators reasoned that 1 out of 1,000 stars in the globular cluster should have planets that "This could be the first tantalizing evidence that conditions for planet formation and evolution may transit once every few days. They predicted that Hubble should discover 17 hot Jupiter-class be fundamentally different elsewhere in the galaxy," says Mario Livio of the Space Telescope planets. Science Institute (STScI) in Baltimore, MD. To catch a planet in a several-day orbit, Gilliland had Hubble's "eagle eye" trained on the cluster The bold and innovative observation pushed NASA Hubble Space Telescope's capabilities to its for eight consecutive days. The result was the most data-intensive observation ever done by limits, simultaneously scanning for small changes in the light from 35,000 stars in the globular star Hubble. STScI archived over 1,300 exposures during the observation. Gilliland and Brown sifted cluster 47 Tucanae, located 15,000 light-years (4 kiloparsecs) away in the southern constellation through the results and came up with 100 variable stars, some of them eclipsing binaries where the Tucana. companion is a star and not a planet. But none of them had the characteristic light curve that Hubble researchers caution that the finding must be tempered by the fact that some astronomers would be the signature of an extrasolar planet. always considered the ancient globular cluster an unlikely abode for planets for a variety of There are a variety of reasons the globular cluster environment may inhibit planet formation. 47 reasons. Specifically, the cluster has a deficiency of heavier elements that may be needed for Tucanae is old and so is deficient in the heavier elements, which were formed later in the universe building planets. If this is the case, then planets may have formed later in the universe's evolution, through the nucleosynthesis of heavier elements in the cores of first-generation stars. Planet when stars were richer in heavier elements. Correspondingly, life as we know it may have appeared surveys show that within 100 light-years of the Sun, heavy-element-rich stars are far more likely to later rather than sooner in the universe. harbor a hot Jupiter than heavy-element-poor stars. However, this is a chicken and egg puzzle Another caveat is that Hubble searched for a specific type of planet called a "hot Jupiter," which is because some theoreticians say that the heavy-element composition of a star may be enhanced considered an oddball among some planet experts. The results do not rule out the possibility that after if it makes Jupiter-like planets and then swallows them as the planet orbit spirals into the star. 47 Tucanae could contain normal solar systems like ours, which Hubble could not have detected. The stars are so tightly compacted in the core of the cluster – being separated by 1/100th the But even if that's the case, the "null" result implies there is still something fundamentally different distance between our Sun and the next nearest star — that gravitational tidal effects may strip between the way planets are made in our own neighborhood and how they are made in the cluster. nascent planets from their parent stars. Also, the high stellar density could disturb the subsequent migration of the planet inward, which parks the hot Jupiters close to the star. 26 Bays Mountain Astronomy Club Newsletter November 2020 Another possibility is that a torrent of ultraviolet light from the earliest and biggest stars, which formed in the cluster billions of years ago may have boiled away fragile embryonic dust disks out of which planets would have formed. These results will be published in The Astrophysical Journal Letters in December. Follow-up observations are needed to determine whether it is the initial conditions associated with planet birth or subsequent influences on evolution in this heavy-element-poor, crowded environment that led to an absence of planets. Credits for Hubble image: NASA and Ron Gilliland (Space Telescope Science Institute)

6. Space Place is a fantastic source of scientific educational materials for children of all ages. Visit them at: http://spaceplace.nasa.gov

7. NGC 3982 Though the universe is chock full of spiral-shaped galaxies, no two look exactly the same. This face-on spiral galaxy, called NGC 3982, is striking for its rich tapestry of star birth, along with its winding arms. The arms are lined with pink star-forming regions of glowing hydrogen, newborn blue star clusters, and obscuring dust lanes that provide the raw material for future generations of stars. The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the center. NGC 3982 is located about 68 million light-years away in the constellation Ursa Major. The galaxy spans about 30,000 light-years, one-third of the size of our Milky Way galaxy. This color image is composed of exposures taken by the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), the Advanced Camera for Surveys (ACS), and the Wide Field Camera 3 (WFC3). The observations were taken between March 2000 and November 2009. The rich color range comes from the fact that the galaxy was photographed invisible and near-infrared light. Also used was a filter that isolates hydrogen emission that emanates from bright star-forming regions dotting the spiral arms. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: A. Riess (STScI)

8. The ISS photobombs the Sun in this amazing image taken during the of August 21, 2017 from Banner, Wyoming. Photo credit: NASA/Joel Kowsky. More info: https://bit.ly/eclipseiss

9. A complete view of the ISS as of October 4, 2018, taken from the Soyuz capsule of the departing crew of Expedition 56 from their Soyuz capsule. This structure was built by materials launched into orbit by 37 United States Space Shuttle missions and five Russian Proton and Soyuz rockets, and assembled and maintained by 230 spacewalks, with more to come! Credit: NASA/ Roscosmos. More info: https://bit.ly/issbasics

27 Bays Mountain Astronomy Club Newsletter November 2020