The Monthly Newsletter of the Bays Mountain Astronomy Club · 2018-12-12 · members used their...

The Monthly Newsletter of the

BaysMountain AstronomyClub

Edited by Adam Thanz M o re o n t h i s i m a g e .

S e e F N 1

January 2019

Chapter 1

Cosmic Reflections

W i l l i a m Tro x e l - B M A C C h a i r

M o re o n t h i s i m a g e .

S e e F N 2

Greetings and Happy New Year fellow BMACers. I hope this article finds everyone well and happy and I hope you have a wonderful holiday season. It is hard to believe that 2019 is here. However, first things first. I want to thank Greg Love for being our speaker for the last meeting in 2018. Greg gave us a wonderful overview of binoculars, some of the characteristics of each and advice on some of the steps to pick which type to start out with. He also suggested other equipment that could be considered. Greg requested that we bring our close-focus binoculars to the meeting. Greg and Adam then turned the dome lights down and members used their binoculars to find certain deep-sky objects on the dome and we tried to see if we could see more detail then we could see with the naked eye. It was very interesting to see how much more opens up when a person adds low powered binoculars. Following that Greg took questions from those present. Thank you again Greg. [Ed.: Accompanying Greg were fellow BMAC members Jocelyn Love and our newest club member, Emma Caroline, aged 7 weeks! Emma was sporting a snazzy celestial garment covered with constellations and who, of course, stole the show.]

Following the business meeting we moved into the lobby where we had snacks and social time.

Our January constellation of interest is Aries, the Ram. The accepted depiction is as a crouched, wingless ram facing Taurus. There are a few different stories about this constellation in ancient texts. It is strange how I can recall some stories easier than others.

The one I recall the best, is the one that my fourth grade teacher would tell during science class. I have to tell you that I have never found this story printed anywhere and can not say if it has any truth. According to Mrs. Moore’s story, Aries got his name because he looked like a large ram with the largest horns ever seen in the world. Aries would spend his time butting his head against everything. It was said that he would plow the Earth by moving an object across the land. Mrs. Moore went on to tell us that Aires would start at the top of the world butting his head against the mountains moving them southward creating the oceans of the world. Aries’s coat turned to gold because of all the gold dust would be deposited into his fleece. Mrs. Moore told the class that the reason he is not on the Milky Way is

William Troxel

Cosmic Reflections

Bays Mountain Astronomy Club Newsletter January 2019 3


S e e F N 3

because he did not do anything great enough for Zeus to let him be on the Milky Way. She would end the story by telling us that each night Aries rams into the Milky Way and pushes it across the night sky trying to get onto the Milky Way.

Stories that most people recall are that of Greek mythology. Aries was the golden ram that was ordered by Hermes, the God of Sports, to rescue Phrixus and Helle. There was an accident when Aries arrived at a destination carrying Phrixus & Helle, killing Helle. Phrixus sacrificed the ram to Zeus and gave the golden fleece to Aeetes of Colchis who rewarded him with the marriage to his daughter. Aeetes hung the fleece in a sacred place that was said to be guarded by a dragon.

Book number two of the modern youth book series, “Percy Jackson and the Olympians: The Sea of Monsters," includes where the golden fleece of Aries was needed to save the camp for the demigods. The book makes reference to the healing powers of Aries' golden fleece. Most historians believe that the golden fleece was only the symbol of kingship and authority in ancient times.

The last story I wanted to share connected with “Aries the Ram” comes from ancient Egypt. Aries was associated with their God, Amon-Ra. He was depicted as having the head of a Ram and the body of a man. Some historians think he was called the indicator of the reborn sun. This is the period at which the Ancient Egyptians connected Aries with its position at the zenith, the

rising of Sirius and the flooding of the Nile River. This annual event was very important to life in the region. Amon Ra was believed to control the Sun and the Earth which to the Egyptians, was everything. He was their King of all Gods.

I encourage you to continue reading Jason's article as he will cover astronomical details of this constellation.

I wrote in my article last month that at this point I wanted to share a couple of astronomy terms. The purpose is to help us refresh our astronomy vocabulary, this month our terms are Aperture and Celestial Equator.

Aperture: In astronomy, this refers to the diameter of a telescope’s main lens or mirror - and is the scope’s most important attribute. As a rule of thumb, a telescope’s maximum useful magnification is 50 times its aperture in inches (or twice its aperture in millimeters).

Celestial Equator: An imaginary line that extends out from the Earths’ equator onto the celestial sphere. It divides the celestial sphere in half (just like the real equator does with Earth) and is used to map stars and other celestial objects.

I very excited to share that our February 2018 meeting will be “Math for Amateur Astronomers” lead by our own Nate Wentzel, Professor of Physics at Milligan College. We will have hands-on exercises for us to do. Mark your calendar for Friday, the 1st of February at 7 p.m.

4 Bays Mountain Astronomy Club Newsletter January 2019

As a heads up, the June club meeting will be moved to the second Friday due to both Adam and Jason being out of town and the City requires at least one of them to be in attendance if on City property. The regular meeting events will be the same except that they will happen on the 14th of June, not the 7th. Please mark your calendars.

Before all of those things, we of course have the Annual Bays Mountain Astronomy Club Dinner. This year our dinner will be at The Meadows Restaurant inside of the MeadowView Resort. The date will be January 12, 2019, the snow date will be the 19th. Listed below are the details for the Annual Dinner.

5:00 - 5:50 Drinks in lounge (should anyone want to come early)

6:00 - 6:15 Seating

6:15 - 6:25 Order placed from menu

6:30 - 7:00 Welcome, Opening Remarks, and Astronomy Game by Chairman (I have a prize to give to the person who solves the game in the shortest amount of time.)

6:35 - 1st course is served

7:05 - until meals are served we can have “share one big astronomy event you traveled to during 2018”

Dinner & conversation

Closing - Chairman

(Please note: times are just approximate, however we are to be seated at 6:00 p.m.) This format is a little different than our other dinners, I think it will be enjoyable. I hope to see you and your families there. Until Next time….

Clear Skies!


Chapter 2

BMACNotes


S e e F N 4

January Annual BMAC DinnerJanuary 12, 2019, 6:00 p.m., The Meadows Restaurant

Snow Date: January 19, 2019

Program (rough draft):

• 5:00 - 5:50 Drinks in lounge (should anyone want to come early)

• 6:00 - 6:15 Seating

• 6:15 - 6:25 Order placed from menu

• 6:30 - 7:00 Welcome, Opening Remarks, and Astronomy Game by Chairman (I have a prize to give to the person who solves the game in the shortest amount of time.)

• 6:35 - 1st course is served

• 7:05 - until meals are served we can have “share one big astronomy event you traveled to during 2018”

• Dinner & conversation

• Closing - Chairman

New Astro-Imaging Website Now OnlineEd.: I received an e-mail from an old friend the other day about a new website from one of his friends posting over 1600 images he has imaged. But, these aren’t the normal pretty pictures you typically see. There is something unusual about them. Usually it relates to their identity. There’s a lot of super-deep faint galaxies. There’s also Eris, Sedna, and more! The website design is simple and the links to the objects are listed alphabetically on one page. There are some pages that illustrate his observatory and home. Take a gander and swim around the Cosmos!

http://www.mantrapskies.com/

BMAC News



S e e F N 3

http://www.mantrapskies.com

http://www.mantrapskies.com


Comet 46P/Wirtanen

This image was taken on Dec. 3, 0316UT. AP130GT f/6.3,

prime focus, 1600 ISO, 4 min. FOV: 1.65° x 2.48°

Image by Adam Thanz


Comet 46P/Wirtanen

This image was taken on Dec. 12, 0307UT. Sony A7ii, 35mm, f2.8 4000 ISO, 15 sec.

The comet is seen to the right. Notice the Pleiades and the Hyades to the left. Visually, the comet was naked eye. Binoculars showed about a

degree fov, twice that of the previous image, nine days earlier.

Image by Adam Thanz

ALPO / SERAL Joint Meeting SetThe ALPO (Association of Lunar and Planetary Observers) and the SERAL (The Southeast Region of the Astronomical League) will have a joint meeting on July 12/13, 2019 (Friday and Saturday) at Gordon State College in Barnesville, GA. The address is 419 College Dr. Barnesville GA 30204.

A preliminary plan is:

• Friday, July 12:

• Talks: 8:30-10:00 and 10:15-11:45 a.m. & 1:30-3:00 and 3:15-5:45 p.m. (8 talks total)

• Coffee breaks: 10:00-10:15 a.m. and 3:00-3:15 p.m.

• ALPO Board Meeting 7:30-9 p.m.

• Optional Star party at Richard Schmude’s Pecan orchard 9:30-11:00 p.m. (about five miles away)

• Saturday July 13:

• Talks: 8:30-10:00 and 10:15-11:45 a.m. & 1:30-3:00 and 3:15-5:45 p.m. (8 talks total)

• Coffee breaks: 10:00-10:15 a.m. and 3:00-3:15 p.m.

• Banquet at Brians or at Gordon State College

• Banquet Speaker: To be determined

Talks: will be 20 minutes, 5 minutes for questions and 5 minutes for set-up. We may have to extend the time of the talks if more people agree to present.


2019 Texas Star Party – Sign up now!The great tradition of dark sky observing continues with the 41st Annual TEXAS STAR PARTY, April 28 – May 5, 2019 near Ft Davis, Texas!

Staying on the Ranch in housing, RV, or camping? Staying off-site in other accommodations? Everyone needs to enter the TSP drawing, held in late January.

You should submit a Registration/Reservation Request Form to ENTER THE TSP DRAWING before January 18, 2019. This will provide you the highest possible chance of being selected as one of the 500 people who will be able to attend TSP this year.

Follow this link to get started!https://texasstarparty.org/get-started/

SIGN UP NOW! You can find out the status of your TSP Registration at any time by visitinghttps://texasstarparty.org/account/

Find the latest news at:https://texasstarparty.org/news/

We have a NEW Texas Imaging Workshops, where you can learn more about imaging from our experts during TSP! https://texasstarparty.org/tsp-imaging-workshops/

Questions? Visit our web site for the latest and complete details! https://texasstarparty.org/ or email [email protected]

We look forward to seeing you next April!

Sincerely, the volunteers for Texas Star Party


https://texasstarparty.org/get-started/

https://texasstarparty.org/get-started/

https://texasstarparty.org/account/

https://texasstarparty.org/account/

https://texasstarparty.org/news/

https://texasstarparty.org/news/

https://texasstarparty.org/tsp-imaging-workshops/

https://texasstarparty.org/tsp-imaging-workshops/

https://texasstarparty.org

https://texasstarparty.org

mailto:[email protected]

mailto:[email protected]


BMAC’s newest member, Emma

Caroline Love, made a surprise visit at the December meeting. Already at 7 weeks,

she is in full command of the Cosmos. She is

attended by her parents Jocelyn and

Greg Love.

Image by Adam Thanz

Chapter 3

Celestial Happenings

J a s o n D o r f m a n


S e e F N 5

Happy New Year! I hope that 2019 brings good health and plenty of happiness for everyone.

2019 begins with some exciting space exploration. On January 1st at 12:33 a.m., the New Horizons spacecraft will fly by a Kuiper Belt object nicknamed Ultima Thule which means "beyond the known world" (it's official designation is 2014 MU69.) This will be the most distant planetary encounter in history and has lots of potential for things to go wrong. New Horizons is moving fast, about 14 km per second! Ultima Thule is small, approximately 30 km in diameter, and irregularly shaped. Back in the spring of last year, Steve Conard from the Johns Hopkins Applied Physics Laboratory, who worked on the New Horizons LORRI instrument, came and spoke to us about an occultation study of Ultima Thule which he helped to coordinate. From one of the successful occultation observations, the team was able to determine that Ultima Thule has an elongated shape with two large lobes. It could be a contact binary - two bodies that are touching, or two separate bodies that are orbiting each other closely. Obviously, at a distance of almost 4 billion miles from the Sun, there is a lot of uncertainty as to what they'll

ultimately encounter. Does the object have some small moons or a ring system? The limited amount of sunlight that reaches the Kuiper Belt is also a factor making it difficult to spot any potential obstacles along New Horizon's path. Hopefully, the flyby will occur without any problems and sometime in the first week of January we will be able to see an image from the spacecraft showing us one of the most primitive planetary objects ever explored.

PlanetsWith the beginning of the new year, we find a single naked-eye planet visible in our evening skies, Mars. It was just 3 months ago in October that all 5 naked-eye planets were observable in the sky just after sunset. One by one they have disappeared into the bright twilight glow of the setting Sun, transitioning over into our morning skies. Looking south an hour after sunset, you'll find the lone Red Planet about 53° above the horizon. At magnitude +0.5, look for its signature orange hue outshining the background stars of Pisces. Mars begins the month almost due south at this time and will remain at about the same altitude an hour after sunset by month's end, but having shifted to the

Jason Dorfman

Celestial Happenings



S e e F N 3

southwest. With the altitude of Mars positioned quite high, you should be able to enjoy some nice views of the Red Planet, though with it's distance now, it is very difficult to see any surface features. Our Earth continues to move ahead in its orbit, increasing the separation between us and Mars. On the first, Mars will appear about 87% illuminated and the disk will span 7.4". By month's end, it will appear just slightly smaller at 6.1", but the illuminated portion will have increased just a bit to 89%.

As mentioned above, all of the other naked-eye planets are now visible in the early morning hours. The first to rise is Venus, just after 4 a.m. on the 1st. It will reach an altitude of about 25° above the southeast horizon a couple hours later and about an hour prior to sunrise. It begins the month at its brightest - magnitude -4.6. Also on the 1st, be sure to notice the thin crescent Moon just 5° to the upper right of Venus. A telescopic view will show the disk of the planet spanning about 26" and 48% lit. Venus will appear roughly the same when it reaches its greatest western elongation on the 6th.

Rising about an hour and half after Venus on the 1st is mighty Jupiter. This gas giant shines at magnitude -1.8 and is currently residing amongst the background stars of Ophiuchus, just 5° to the NE of Antares in Scorpius. An hour before sunup, Jupiter will be about 12° above the SE horizon. The disk of Jupiter spans about 32". This will increase slightly by the 31st to about 33.5". On the 2nd, a thin, waning crescent Moon will be almost midway

between Jupiter and Venus, and will move to roughly 4° to the left of Jupiter on the next morning.

Venus will be moving swiftly eastward over the month. It begins the month in the constellation of Libra and will move into Scorpius passing over the head of the scorpion from the 10th to the 14th, moving then into the southern portion of Ophiuchus. Venus will appear to catch up and overtake Jupiter from the 21st to the 24th. The closest approach will occur on the morning of the 22nd when Venus will be about 2.4° north of Jupiter. On that day, Venus will be at magnitude -4.3 with a 21" diameter disk about 60% illuminated.

Last month, we saw Mercury reach its greatest western elongation on the 15th and begin to head back eastward towards the Sun. For those wanting a glimpse of our smallest planet, your best chances will be on the 1st. Look a little east of southeast about 45 minutes prior to sunup, Mercury will be just under 5° above the horizon, so you'll need a clear view of the horizon. At magnitude -0.4, you should be able to pull it from the twilight glow of the rising Sun with a pair of binoculars.

As we arrive at the end of the month, the Moon, having completed a complete orbit around Earth, will once again find itself positioned between Venus and Jupiter. The two planets will be separated by about 9° with the waning crescent Moon just 2° west of Venus. You'll find the trio about 20° above the SE horizon an hour before sunrise. Saturn will have just risen towards the



Aries

Image from Stellarium

east and will be about 5° high at that time shining brilliantly at magnitude +0.6.

Constellation of the MonthOur constellation for the month is Aries and continues our look at some smaller and often overlooked constellations. Aries is one of the constellations of the zodiac, centered at a declination of 20° north and bordered by Taurus to the east and Pisces to the west. Perseus and Triangulum are to the north and Cetus completes its boundary to the south. I think many of us often think of and identify Aries by its three brightest stars located in the northwest part of the constellation - Hamal, Sheratan, and Mesarthim (!, ",

and #, respectively.) The constellation, however, extends a bit

beyond this, about 20° to the east and 10° south.

There are quite a few double and multiple stars and about a dozen variable stars in Aries. However, when it comes to brighter deep-sky objects, Aries is quite lacking, which is not surprising given its location away from the disk of the Milky Way. There are several galaxies but all are magnitude 12 or fainter and there are no Messier objects.

LunaLast January, there were two Full Moons, one of which was a "Supermoon," and there was also a total lunar eclipse, which, unfortunately, wasn't visible for our location. As luck would have it, this January is going to be somewhat similar with the Full Moon

occurring when the Moon is at perigee and aligned with the ecliptic plane. As mentioned in the Planets section above, the month begins with a waning crescent Moon in our morning skies. The Moon will swing around the Earth and show itself in the early evening sky as we begin the second week of the month. On the 12th, a fuller crescent Moon will lie about 5° to the lower left of Mars.

Lunar EclipseFull Moon occurs on the night of the 20th. Due to the position of the Moon in its orbit and the orientation of the Moon's orbit with respect to the Sun, this Full Moon will be a "supermoon" and a total lunar eclipse will also occur that night. The entire lunar eclipse will be visible from all of North and South America. The eclipse begins at 9:36 p.m. EST when the Moon begins to enter the Earth's outer penumbral shadow. It will be difficult to notice much of a change in the Moon's appearance until about 10:33 p.m. when the Moon begins to enter the inner and darker umbral shadow of Earth. You'll notice a distinct shadow moving from east to west. Totality begins at 11:41 p.m. when the Moon is completely enveloped by the Earth's shadow and will last for 1 hour and 2 minutes. Maximum eclipse occurs just after midnight at 12:12 a.m. and totality will last another 30 minutes until 12:43 a.m. The Moon will then, once again, appear partially eclipsed as it begins to exit the umbral shadow. At 1:50 a.m. the Moon will be out of the umbral shadow and the eclipse will end at 2:48 a.m. as the Moon exits the penumbral shadow. See the included image



Details of the lunar eclipse on January 21, 2019.

Note: The eclipse starts on the evening of the 20th. Greatest eclipse is 12:12 a.m. on the

21st.

Credit: F. Espenak, NASA’s GSFC

from NASA for more detailed information.

Quadrantids Meteor ShowerThe peak night for the Quadrantids occurs on the night of the 3rd/4th. The sky will be moonless as the Moon will be a thin waning crescent on that day. The radiant for this shower lies in the constellation of Boötes, the herdsman, just above his head. On the peak night at around 2 a.m., the radiant will be about 20° above the northeast horizon. The listed ZHR (Zenithal Hourly Rate) for the Quadrantids is 120, but this assumes a dark sky and the radiant high overhead. For our location, expect an average rate of about 25 per hour. The Quadrantid meteors usually lack persistent trains but have been known to produce some bright fireballs.

Wishing you all great views of the skies above for 2019!


Chapter 4

TheQueenSpeaks

R o b i n B y r n e

Before I review the book, there is a story I must tell. I first heard about This Book is a Planetarium (and other Extraordinary Pop-Up Contraptions) by Kelli Anderson in late Fall 2014, when it was available for pre-order on Amazon. It seemed like it would be the perfect gift for Adam, combining both pop-ups (which we love) and planetariums, so I pre-ordered it. As the delivery date approached, I got an email from Amazon saying the delivery date was going to be delayed. No worries. I can wait. Then another email came with another delay. And another…. Long story short, the book arrived about three and a half years after I first ordered it. I have no idea what the delays were for, whether manufacturing problems, or waiting for enough pre-orders to cover the cost of printing, or something else entirely. The important part is that it did finally arrive. [Ed.: And people think I waited a long time for a telescope…!]

Now for the book. It was worth the wait. Each page has a beautiful graphic design quality. Printed on very thick card stock, the book is sturdy for holding the shape of the pop-ups. Each pop-up is very interactive, with printed instructions on what to do.

It begins with a stringed instrument and pick for plucking out a tune. With five strings, you can create a melody, and the sound quality isn’t too bad, considering it’s a book. Next up, a decoder ring. Having recently watched A Christmas Story, I couldn’t help but think, “Be sure to drink your Ovaltine.” Just like the Little Orphan Annie decoder ring in the movie, this one is set by a certain number, and lines up the letters to be swapped. A perpetual calendar appears on the adjacent page to the decoder ring. With years from 2012 to 2054, you can see what dates fall on each day of the week by lining up the year with the month. The planetarium is what I was most interested in. It is designed to use the flashlight on a smart phone as the light source to project the constellations of the fall sky onto your ceiling through the holes of the paper dome. Although fuzzy, the projected image isn’t bad, and very bright. The speaker, also designed to work with a cell phone, didn’t work as well. Intended to help amplify the sound, I only heard a slight increase in volume. The last page is a spiralgraph (not to be confused with a Spirograph™). You’re given a place to insert a piece of paper with a round window, and 4 different discs shaped like cogs that run around the circumference of the opening. Each cog has a

Robin Byrne

Book Review: This Book is a Planetarium



S e e F N 3


The cover to This Book is a Planetarium by

Kelli Anderson.

Image by Adam Thanz


This illustrates the planetarium pop-up. You slide a cell phone, or other light source, inside.

Image by Adam Thanz

variety of holes in it to use for drawing shapes. Much like the mass-produced version, the trickiest part is keeping the cogs lined up properly around the opening so that it doesn’t slip. As long as you’re careful, you will get a cool final product.

Each pop-up includes easy-to-follow instructions. Most pages also have a paragraph or two to explain the principle behind the device. If thinking about this book as a gift for a child, I would say that young teens on up would be able to manipulate the pop-ups and understand the explanations. Of course, geeky geezers like me would also enjoy it. So, whether indulging your inner child, or giving a cool gift to an actual kid, This Book is a Planetarium is an excellent choice.

References:

This Book is a Planetarium by Kelli Anderson, Chronicle Books LLC, 2017


Chapter 5

BMAC

Calendar

and more


S e e F N 7

BMAC Calendar and more



S e e F N 3

Date Time Location NotesB M A C M e e t i n g sB M A C M e e t i n g sB M A C M e e t i n g sB M A C M e e t i n g s

Friday, February 1, 2019 7 p.m.Nature Center

Discovery TheaterProgram: Dr. Nathaniel Wentzel, Assistant Professor of Physics at Milligan College will be leading a workshop

entitled: "Math for Amateur Astronomers." Free.

Friday, March 1, 2019 7 p.m.Nature Center

Discovery TheaterProgram: Program TBA; Free.

Friday, April 5, 2019 7 p.m.Nature Center

Discovery TheaterProgram: Program TBA; Free.

S u n W a t c hS u n W a t c hS u n W a t c hS u n W a t c h

Every Saturday & SundayMarch - October

3-3:30 p.m. if clear

At the dam View the Sun safely with a white-light view if clear.; Free.

S t a r W a t c hS t a r W a t c hS t a r W a t c hS t a r W a t c h

Mar. 2, 9, 2019 7 p.m.

ObservatoryView the night sky with large telescopes. If poor weather, an alternate live tour of the night sky will be held in the

planetarium theater.; Free.Mar. 16, 23, 30, 2019 8 p.m. Observatory

View the night sky with large telescopes. If poor weather, an alternate live tour of the night sky will be held in the planetarium theater.; Free.

Apr. 6, 13, 20, 27, 2019 8:30 p.m.

ObservatoryView the night sky with large telescopes. If poor weather, an alternate live tour of the night sky will be held in the

planetarium theater.; Free.

S p e c i a l E v e n t sS p e c i a l E v e n t sS p e c i a l E v e n t sS p e c i a l E v e n t s

Saturday, January 12, 2019 6 p.m.

The Meadows Restaurant at the

MeadowView Marriott Resort

Annual BMAC Dinner. Drinks start at 5 p.m. in the lounge. We’ll sit for dinner by 6. Family members are welcome to attend. The Saturday a week later is the snow date.

Saturday, May 11, 20191-4:30 p.m.8:30-9:30

p.m.

Nature Center& Observatory

Annual Astronomy Day - Displays et al. on the walkway leading to the Nature Center, 1-4:30 p.m.; Solar viewing 3-3:30 p.m. at the dam; Night viewing 8:30-9:30 p.m. at the observatory. All non-planetarium astronomy

activities are free.

Bays Mountain Astronomy Club

853 Bays Mountain Park Road

Kingsport, TN 37650

1 (423) 229-9447

www.BaysMountain.com

[email protected]

Annual Dues:

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.

$16 /person/year

$6 /additional family member

Note: if you are a Park Association member (which incurs an additional fee), then a 50% reduction in BMAC dues are applied.

The club’s website can be found here:

https://www.baysmountain.com/astronomy/astronomy-club/#newsletters

Regular Contributors:William Troxel

William is the current chair of the club. He enjoys everything to do with astronomy,

including sharing this exciting and interesting hobby with anyone that will

listen! He has been a member since 2010.

Robin Byrne

Robin has been writing the science history column since 1992 and was chair in 1997.

She is an Associate Professor of Astronomy & Physics at Northeast State

Community College (NSCC).

Jason Dorfman

Jason works as a planetarium creative and technical genius at Bays Mountain Park.

He has been a member since 2006.

Adam Thanz

Adam has been the Editor for all but a number of months since 1992. He is the

Planetarium Director at Bays Mountain Park as well as an astronomy adjunct for

NSCC.


http://www.BaysMountain.com

http://www.BaysMountain.com

mailto:[email protected]?subject=

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Footnotes:1. The Rite of SpringOf the countless equinoxes 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 Earth … none other than our faithful robotic explorer, Cassini.Seen from our planet, the view of Saturn’s rings during equinox is extremely foreshortened and limited. But in orbit around Saturn, Cassini had no such problems. From 20 degrees above the ring plane, Cassini’s wide angle camera shot 75 exposures in succession for this mosaic showing Saturn, its rings, and a few of its moons a day and a half after exact Saturn equinox, when the sun’s disk was exactly overhead at the planet’s equator.The novel illumination geometry that accompanies equinox lowers the sun’s angle to the ring plane, significantly darkens the rings, and causes out-of-plane structures to look anomalously bright and to cast shadows across the rings. These scenes are possible only during the few months before and after Saturn’s equinox which occurs only once in about 15 Earth years. Before and after equinox, Cassini’s cameras have spotted not only the predictable shadows of some of Saturn’s moons (see PIA11657), but also the shadows of newly revealed vertical structures in the rings themselves (see PIA11665).Also at equinox, the shadows of the planet’s expansive rings are compressed into a single, 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.)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 then digitally processed to make the image “joints” seamless and to remove lens flares, radially 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 dominates any meager sunlight falling on the rings. Hence, the half of the rings on the left illuminated by planetshine is, before processing, much brighter than the half of the rings on the right. On the right, it is only the vertically extended parts of the rings that catch any substantial sunlight.With no enhancement, the rings would be essentially invisible in this mosaic. To improve their visibility, the dark (right) half of the rings has been brightened relative to the brighter (left) half by a 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, than they would have appeared if the entire system, planet included, could have been captured in a single image.The moon Janus (179 kilometers, 111 miles across) is on the lower left of this image. Epimetheus (113 kilometers, 70 miles across) appears near the middle bottom. Pandora (81 kilometers, 50

miles across) orbits outside the rings on the right of the image. The small moon Atlas (30 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 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.This view looks toward the northern side of the rings from about 20 degrees above the ring plane.The images were taken on Aug. 12, 2009, beginning about 1.25 days after exact equinox, using the red, green and blue spectral filters of the wide angle camera and were combined to create this natural color view. The images were obtained at a distance of approximately 847,000 kilometers (526,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 74 degrees. Image scale is 50 kilometers (31 miles) per pixel.The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The Cassini imaging team homepage is at http://ciclops.org.Image Credit: NASA/JPL/Space Science Institute

2. Leo RisingA sky filled with stars and a thin veil of clouds.Image by Adam Thanz

3. The Cat's Eye Nebula, one of the first planetary nebulae discovered, also has one of the most complex forms known to this kind of nebula. Eleven rings, or shells, of gas make up the Cat's Eye.Credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)Acknowledgment: R. Corradi (Isaac Newton Group of Telescopes, Spain) and Z. Tsvetanov (NASA)

4. Jupiter & GanymedeNASA'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 planet.

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http://saturn.jpl.nasa.gov

http://saturn.jpl.nasa.gov

http://ciclops.org

http://ciclops.org

Ganymede completes an orbit around Jupiter every seven days. Because Ganymede's orbit is tilted nearly edge-on to Earth, it routinely can be seen passing in front of and disappearing behind its giant host, only to reemerge later.Composed of rock and ice, Ganymede is the largest moon in our solar system. It is even larger than the planet Mercury. But Ganymede looks like a dirty snowball next to Jupiter, the largest planet in our solar system. Jupiter is so big that only part of its Southern Hemisphere can be seen in this image.Hubble's view is so sharp that astronomers can see features on Ganymede's surface, most notably the white impact crater, Tros, and its system of rays, bright streaks of material blasted from the crater. Tros and its ray system are roughly the width of Arizona.The image also shows Jupiter's Great Red Spot, the large eye-shaped feature at upper left. A storm the size of two Earths, the Great Red Spot has been raging for more than 300 years. Hubble's sharp view of the gas giant planet also reveals the texture of the clouds in the Jovian atmosphere as well as various other storms and vortices.Astronomers use these images to study Jupiter's upper atmosphere. As Ganymede passes behind the giant planet, it reflects sunlight, which then passes through Jupiter's atmosphere. Imprinted on that light is information about the gas giant's atmosphere, which yields clues about the properties of Jupiter's high-altitude haze above the cloud tops.This color image was made from three images taken on April 9, 2007, with the Wide Field Planetary Camera 2 in red, green, and blue filters. The image shows Jupiter and Ganymede in close to natural colors.Credit: NASA, ESA, and E. Karkoschka (University of Arizona)

5. 47 TucanaeIn the first attempt to systematically search for "extrasolar" planets far beyond our local stellar neighborhood, astronomers probed the heart of a distant globular star cluster and were surprised to come up with a score of "zero".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."This could be the first tantalizing evidence that conditions for planet formation and evolution may be fundamentally different elsewhere in the galaxy," says Mario Livio of the Space Telescope Science Institute (STScI) in Baltimore, MD.The bold and innovative observation pushed NASA Hubble Space Telescope's capabilities to its limits, simultaneously scanning for small changes in the light from 35,000 stars in the globular star cluster 47 Tucanae, located 15,000 light-years (4 kiloparsecs) away in the southern constellation Tucana.Hubble researchers caution that the finding must be tempered by the fact that some astronomers always considered the ancient globular cluster an unlikely abode for planets for a variety of reasons. Specifically, the cluster has a deficiency of heavier elements that may be needed for building planets. If this is the case, then planets may have formed later in the universe's evolution, when stars were richer in heavier elements. Correspondingly, life as we know it may have appeared later rather than sooner in the universe.Another caveat is that Hubble searched for a specific type of planet called a "hot Jupiter," which is considered an oddball among some planet experts. The results do not rule out the possibility that 47 Tucanae could contain normal solar systems like ours, which Hubble could not have detected. But even if that's the case, the "null" result implies there is still something fundamentally different between the way planets are made in our own neighborhood and how they are made in the cluster.

Hubble couldn't directly view the planets, but instead employed a powerful search technique where the telescope measures the slight dimming of a star due to the passage of a planet in front of it, an event called a transit. The planet would have to be a bit larger than Jupiter to block enough light — about one percent — to be measurable by Hubble; Earth-like planets are too small.However, an outside observer would have to watch our Sun for as long as 12 years before ever having a chance of seeing Jupiter briefly transit the Sun's face. The Hubble observation was capable of only catching those planetary transits that happen every few days. This would happen if the planet were in an orbit less than 1/20 Earth's distance from the Sun, placing it even closer to the star than the scorched planet Mercury — hence the name "hot Jupiter."Why expect to find such a weird planet in the first place?Based on radial-velocity surveys from ground-based telescopes, which measure the slight wobble in a star due to the small tug of an unseen companion, astronomers have found nine hot Jupiters in our local stellar neighborhood. Statistically this means one percent of all stars should have such planets. It's estimated that the orbits of 10 percent of these planets are tilted edge-on to Earth and so transit the face of their star.In 1999, the first observation of a transiting planet was made by ground-based telescopes. The planet, with a 3.5-day period, had previously been detected by radial-velocity surveys, but this was a unique, independent confirmation. In a separate program to study a planet in these revealing circumstances, Ron Gilliland (STScI) and lead investigator Tim Brown (National Center for Atmospheric Research, Boulder, CO) demonstrated Hubble's exquisite ability to do precise 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-sized moons, if they existed.But to discover new planets by transits, Gilliland had to crowd a lot of stars into Hubble's narrow field of view. The ideal target was the magnificent southern globular star cluster 47 Tucanae, one of the closest clusters to Earth. Within a single Hubble picture Gilliland could observe 35,000 stars at once. Like making a time-lapse movie, he had to take sequential snapshots of the cluster, looking for a telltale dimming of a star and recording any light curve that would be the true signature of a planet.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 transit once every few days. They predicted that Hubble should discover 17 hot Jupiter-class planets.To catch a planet in a several-day orbit, Gilliland had Hubble's "eagle eye" trained on the cluster for eight consecutive days. The result was the most data-intensive observation ever done by Hubble. STScI archived over 1,300 exposures during the observation. Gilliland and Brown sifted through the results and came up with 100 variable stars, some of them eclipsing binaries where the companion is a star and not a planet. But none of them had the characteristic light curve that would be the signature of an extrasolar planet.There are a variety of reasons the globular cluster environment may inhibit planet formation. 47 Tucanae is old and so is deficient in the heavier elements, which were formed later in the universe through the nucleosynthesis of heavier elements in the cores of first-generation stars. Planet surveys show that within 100 light-years of the Sun, heavy-element-rich stars are far more likely to harbor a hot Jupiter than heavy-element-poor stars. However, this is a chicken and egg puzzle because some theoreticians say that the heavy-element composition of a star may be enhanced after if it makes Jupiter-like planets and then swallows them as the planet orbit spirals into the star.The stars are so tightly compacted in the core of the cluster – being separated by 1/100th the distance between our Sun and the next nearest star — that gravitational tidal effects may strip 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.


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 3982Though 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 January 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)


http://spaceplace.nasa.gov

http://spaceplace.nasa.gov

The Monthly Newsletter of the Bays Mountain Astronomy Club · 2018-12-12 · members used their...

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Transcript of The Monthly Newsletter of the Bays Mountain Astronomy Club · 2018-12-12 · members used their...