The Observer of the Twin City Amateur Astronomers

THE OBSERVER OF THE TWIN CITY AMATEUR ASTRONOMERS

Volume 41, Number 4 April 2016

INSIDE THIS ISSUE:

Editor’s Choice: Image of the Month……..……………….1 President’s Log..………………………………….………..……….2 Calendar of Celestial Events – March 2016…………....3 New & Renewing Members/Dues Blues…………..…….3 Subscribing to Our E-Mail Lists………………………….……3 This Month’s Phases of the Moon……..……………...…..4 March 22nd Board Meeting Minutes………………..……..4 NCRAL 2016 Planning Committee Notes………………...6 AstroBits…………………………………………………………….….7 March 2016 POS Well Attended……………………………..9 Skynet Junior Scholars…………………………………………...9 Get Ready Now for May 9th Transit of Mercury….…10 AstroBits (continued)………………...... …….…...……11 TCAA Guides Coming………………………………….………..12 Image of the Month (continued)…………………………..12 Introduction to Amateur Astronomy…………………...13 Thoughts from Life at Sea: Part 2………………………….14 A Visit to Johnson Space Center…………………………...15 For Sale: 17.5” Dobsonian Telescope……………….…..16 Sun Funnel Material Available for Purchase……….…16 SGNC Wish List……………………………………………………..16 Estimating the Distance of M67……………………………16 TCAA on Facebook and Twitter…………………………….17

2016’s Second POS April 2nd…………………………………18 EDITOR’S CHOICE: IMAGE OF THE MONTH – LEO TRIO Remaining Public Observing Sessions for 2016……..18 The Eclipse…………………………………………………...………19 By Tim Stone – March has been a terrible month for astronomy, with HowTimeFlies……………………………………………………….20 virtually continuous cloud cover. The evening of the 28th was an TCAA Treasurer’s Report: April 2016………….……..….20 exception. Before the moon rose we had beautiful, crystal clear skies, which afforded a few hours of photography. In those few hours I was able to get enough data on the 16" to create this image. These three galaxies, M65, M66, and NGC 3628 are referred to as "The Leo Trio." At a distance of 32 million light years, not only are they close to us, they are physically close to each other. Their disruptive influence on each other are quite apparent. The galaxy at the upper left is M66, a heavily disrupted spiral galaxy. To the lower left is M65, seemingly relatively unaffected by the three- way dance. Its heavy dark dust lanes and off center nucleus tell us it is not immune to the gravitational influence of its neighbors. To the right is NGC 3628. It is often called "The Hamburger" for reasons apparent to The TCAA is an affiliate of the Astronomical League. some. It's a bit of a stretch for me. It is a spiral galaxy, seen edge-on For more information about the TCAA, be certain to from our perspective. It has been warped and mangled by interactions visit our club website. with M65 and M66. (Continued on page 12.)

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

PRESIDENT’S LOG The OBSERVER is the monthly electronic newsletter of the Twin With the first of our 2016 Public Observing Sessions City Amateur Astronomers, Inc., a already behind us, our season of public outreach is registered 501(c)(3) not-for-profit under way. The evening of March 5th was cold and educational organization of amateur cloudy, but even the most optimistic of us didn’t astronomers interested in studying foresee the number of people who came to hear about astronomy and sharing their hobby the Great Nebula of Orion. All told, around 50 people with the public. attended the first POS. If that’s any indication, we might well be on our way to another record-breaking year. TCAA OFFICERS While these Public Observing Sessions are President & Director/Property Manager fundamental to the values of our organization, what Tim Stone 309-531-2401 you may not realize is that they are also required as a term of our contract with the [email protected] Sugar Grove Nature Center, and to directly support our Educational 501c3 status with Vice President & Director the Federal Government. When TCAA members and public alike come to these events, Robert Finnigan 309-846-9533 they not only learn something and participate in activities that are part and parcel of [email protected] the purpose of our club, but they also support the club’s good standing as a tax-exempt Treasurer & Director charitable organization. So I’d like to thank ahead of time all of the members who Dave Osenga 309-287-0789 participate in our Public Observing Sessions, as presenters, organizers, observers, or [email protected] learners, for helping the club achieve our goals.

Secretary & Director/Historian/Editor Speaking of observing, the cold weather of winter is leaving our clime, and the Carl J. Wenning 309-830-4085 balmier (and relatively bug-free) nights of spring are here. The winter sky lingers in the [email protected] southwest, and the incredible galaxy fields of Leo, Virgo, Coma Berenices, Canis Major,

5th Director and Canes Venatici are rising in the east. With the 11” Celestron fully operational in the Tom Weiland 309-830-0167 Sugar Grove Observatory, this is the perfect time to pick up those objects that will soon [email protected] be lost in the evening twilight, and get started on all those galaxies you’ve been

ALCor/Registered Agent wanting to add to your observing log. The 11” is simple to use, and soon we will have Duane Yockey 309-452-3936 clear and easy to follow instructions on how to start it up, point it, and shut it down. [email protected] Members of the club have gone to great lengths and effort to make this first class

Webmaster observing system available to all our members, and I hope you will come out and find Lee Green 309-454-7349 out how much fun and productive the use of a permanently mounted instrument can [email protected] be. If you are not currently a key-holder and would like to use the system, you can drop an email to myself or Carl Wenning. Lighting Education Coordinator Lisa Wentzel unlisted number To help our members who want to “start with the basics” of amateur astronomy, [email protected] Carl is creating a three-part members-only course titled Introduction to Amateur Astronomy. Instruction in the use of the 11” in the SGO will be included in that course. Membership Coordinator Tom Willmitch 309-846-2423 Dates have yet to be announced, but seats are limited, so get your name in early if [email protected] you’re interested. See the article in this issue of The OBSERVER for more information. If you haven’t already registered for the North Central Region of the Astronomical The OBSERVER League 2016 Conference, being hosted by the TCAA in April, you’re not too late. It’s Carl J. Wenning, Editor going to be a great conference, and we hope to see you there. Paul Pouliot, Assistant Editor The TCAA is planning a special observing session for the May 9 solar transit of Submission deadline is normally one Mercury. This is a very rare opportunity to see one of the inner planets silhouetted day before the end of each month. against the solar disk. If you recall, the Venus transit was observed by hundreds of people at the Sugar Grove Nature Center. This time we are going to have the observing MEMBERSHIP DUES session in Bloomington at Tipton Park. If history holds true, the increased convenience Individual Adult/Family $40 factor of staying in town could result in an even larger crowd this time around! If you’re Full-time Student/Senior $25 a member, please do consider making arrangements to be there. If our projections of (Senior status equals ages 60+) the number of people are realized, we will need all the help we can get.

To join, send your name, contact TCAA is off to a terrific start for 2016. Make the decision to get more involved than info and dues payment to Dave you were last year. Contact any of the officers if you would like to get involved in a new Osenga, TCAA Treasurer, 1109 N. way this year. You won’t regret it! Linden St., Normal, IL 61761-1471. Clear skies! Tim Stone, President

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

ALENDAR OF ELESTIAL VENTS PRIL NEW & RENEWING MEMBERS C C E – A 2016

MORNING STARS (4/15): Venus, Mars, Saturn, Uranus, The following individuals have paid dues for new or and Neptune renewed memberships as of March 31st, 2016. (Others EVENING STARS (4/15): Mercury, Jupiter who paid after that date will appear in the May 2016 issue of The OBSERVER.) Question: Mercury is at its greatest eastern elongation on the 18th, but located in the western sky. How is this New: None possible? Renewing: Roy Lawry, John Werner 6 Moon and Venus – Look for the incredibly thin 1.5% illuminated moon to the lower left of Venus this DUES BLUES morning. 7 New Moon – Sets at sunset and rises at sunrise; not If you have received a “your dues are due” statement visible. along with the email that brought you this issue of The OBSERVER, please remit your dues to Mr. Dave Osenga, 13 First Quarter Moon – The waxing moon rises TCAA Treasurer, 1109 N. Linden St., Normal, IL 61761- around midday and sets around midnight. 1471. Dues are currently $25 for seniors (60 years of age 18 Mercury at Greatest Eastern Elongation – Mercury is and over) and $40 regular. located 19.9 degrees from the sun and is visible in the western sky after sunset. Look for the planet low in the SUBSCRIBING TO OUR E-MAIL LISTS west just after sunset. 22 Full Moon – The moon rises at sunset and sets at By subscribing to a group’s mailing list you will receive sunrise. It is visible all night long. Early Native American email messages from the group so you won’t have access tribes knew this full moon as the Full Worm Moon to the group’s web features (like photos, files, links, polls, because this is the time of year when the ground would calendar, etc.) unless members activate it later. The club begin to soften and the earthworms would reappear. now has two open email listservs. The first email listserv is known as the TCAA Yahoogroups listserv. It will be used to 22/23 Lyrids Meteor Shower – The event will be all but share announcements and reminders about astronomical invisible this year because of the presence of the full moon. and club events. To join this main listserv you must do the following: 29 Last Quarter Moon – The waning moon rises around midnight and sets around midday. 1. Subscribe: Send a blank email to TCAA- [email protected] Note: You’ll be sent a 29/30 NCRAL 2016 – Hosted by TCAA @ HCC. Don’t miss it! confirmation email from the group. Reply to the Answer: The directions of Earth are mirrored in the sky confirmation email to activate your subscription. compared to an Earth map. Consider the sun at midday. 2. Unsubscribe: [email protected] To the left of the sun is east; to the right of the sun is 3. To post a message: [email protected] west. Now, if Mercury is at its greatest angle east of the sun, it is at its greatest distance to the left of the sun. As A second listserv – TCAA–imaging – is for club the sun moves to the right across the sky due to Earth’s astronomical photographers as well as those who want to rotation, it sets before Mercury. The speedy planet is view their images and follow their discussions. It is an easy therefore found in the west after sunset. way to keep up with all the stuff we’re doing at the observatories.

EVENING SKY MAP 1. Subscribe: [email protected] 2. Unsubscribe: [email protected] Click on either of the icons found 3. To post a message: [email protected] here to access a current evening sky map along with a more detailed Once members join a Yahoo! group, they can manage celestial events calendar. group and subscription settings whenever it is desired to

customize the group experience.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

THIS MONTH’S PHASES OF THE MOON

New Moon First Quarter Full Moon Last Quarter April 7 April 13 April 22 April 29 All moon phase dates are given for Central Standard Time. Additional moon phases can be found for the 2016 calendar year by clicking here. These four images were provided by J. K. Howell of the Champaign-Urbana Astronomical Society and are used with permission.

MARCH 22ND BOARD MEETING MINUTES

The meeting was called to order at 6:31 PM at Lewis, consistent set of eyepieces for the Celestron 11” HD Yockey & Brown in downtown Bloomington. In attendance telescope, and that the club’s Coulter Odyssey 8” telescope were the following: Tim Stone, Lisa Wentzel, Bob Finnigan, had been put out on loan to Pete and Daniel Kates. Bob Tom Weiland, Carl Wenning, Dave Osenga, and Duane reported that the work started on the ground floor of SGO is Yockey. Tim led off the meeting by presenting the agenda awaiting warmer weather for completion, and that phase II and calling for additional agenda items. Hearing none, the of the remodeling effort will begin on March 24th. officer reports commenced. ALCor Duane reported that he had received a letter of thanks on behalf of the McLean County Museum, and that Officer Reports: Rich Tennis wants to sell his 17.5” telescope. Carl was asked Tim gave the president’s report noting that the Board to put pertinent information in the newsletter. had received several motions and approved them electronically since the last Board meeting. (Those motions Old Business: are appended to these minutes.)  Lisa and Tom reported that they have been in contact with Carl gave the secretary’s report noting that the minutes Jill as SGNC about the light pollution display. Lisa has of the Board meetings during January and February were prepared a PowerPoint showing the basic information to published in the March issue of The OBSERVER. Both sets of be included in the display. The display will likely need minutes were approved as published. some funding for construction in the near future. Dave noted that he had no treasurer’s report as things  Dave reported that the Treasurer’s audit and were still in the transition process. Duane noted that the documentation of procedures are not yet done, but that latest treasurer’s report was published in the newsletter. It he and Duane have been reviewing procedures including was accepted as published. Duane noted that the bank will data as far back as 2002. only accept direction from Lee Green in terms of making  Tim and Bob reported that they have been working the changes to the signatory agents on the account. It was inventory for tax purposes. Duane will send Tim the official agreed that Dave and Tim would be the signatories. Tim will inventory spreadsheet that Tim will update it and turn it contact Lee about approval for changes in signatories. over to Dave shortly. Lee Green was not present to give his web master  Carl mentioned that Bob Hoy will be giving the April 5th report. Several noted that his email has not been working POS talk. As Mr. Hoy is not a key holder, several of those recently. present noted that they would be there to assist. Tim provided a written property manager’s report the  Tim noted that the telescope status page on the club main gist of which was that the transfer of the various website is functional; Carl noted that it is visible only after telescopes was now mostly complete, that the work of logging in. remodeling SGO was still in progress, that we need a good

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

 Tim reported that hooks and grommets on the vinyl poster  An offer was made by an anonymous donor to renew the showing the Pleiades still needs to be installed; Tom noted G. Weldon Schuette Society of Outstanding Amateur that he will speak with Angela Funk about putting Astronomers. The donor will pay for the new plaque, necessary hooks on the exterior of PSO and SGO to including on it information about Weldon so that the club accommodate the club banner and the Pleiades poster. doesn’t entirely forget this very active TCAAer of the past.  It was noted that the drawing prize for 2016 POS was in  The Board agreed to promote our newsletter editor for the club’s possession, but Tim has yet to check it out fully. the Astronomical League’s Mabel Sterns Award for the It was agreed that Bob, who now holds the non-function second year running. Tim will prepare the necessary letter SkyScout from last year, may dispose of it. of recommendation, and Carl will identify what he  Carl noted that he is still working with Alyssa Hollmann at considers his best issue of the last year. The nomination is Camp Ondessonk about the 2017 total solar eclipse, and due on March 31st. that a tentative program has been worked out. He noted  Carl asked for assistance in reviewing six new TCAA guides. that only those who are actually presenting in some form They will be made available in MS Word format to those will have free access to the camp; family members will who express an interest to review the following: have to pay fees if attending otherwise. 1. Introduction to Amateur Astronomy New Business: 2. Membership & Benefits  The president appointed the following committee heads 3. Astronomy as a Hobby with their approval: editor & historian, Carl Wenning; 4. The Art of Sky Interpretation membership chairperson, Tom Willmitch; lighting 5. Coordinating Observing Sessions education coordinator, Lisa Wentzel; ALCor & registered 6. Introductory Astrophotography agent, Duane Yockey; web master, Lee Green; and property manager, Tim Stone.  Carl noted that we need to prepare now for the transit of  Carl distributed sections of the Bylaws pertaining to officer Mercury on May 9th. The Board approved a public duties. He asked them to review their duties so that observing session to be held, ostensibly, at Bloomington’s nothing gets overlooked. north unit of Tipton Park. Carl will arrange for the event  It was noted that the recently amended Bylaws must running from 9:00 AM to 1:00 PM. He will also write a replace those currently posted on the web. Tim will press release about this event following approval of contact Lee Green about this. Bloomington Parks & Recreation Department.  It was agreed that a committee be formed to review  The Board agreed to consider a special membership offer Bylaws to reverse any actions reducing the number of for past members. Carl will lead a committee of volunteers active club leaders. Tim appointed Carl (chair), Lisa, and to assist with this effort. Volunteers are welcome. Bob to this committee to report out at the May meeting of  Carl asked to put planning for the September 24th Mini the Board. Conference on hold as it incurs a considerable expense in  The Board reauthorized another $200 on the club credit time, treasure, and talent to pull off. It will be held with card in that the previous appropriation has been speakers and a meal only if area astronomy clubs show exhausted by recent purchases of power supplies and sufficient interest by attending NCRAL 2016. Otherwise, it hubs. will merely become a joint observing session.  It was agreed that Carl may teach his Introduction to  Due to the meeting running long, the review of the club’s Amateur Astronomy course charging a fee of to $25 per 5-year plan was tabled. person to cover the cost of facility usage and supplies.  The next meeting of the Board will be on Tuesday, May Working through Tim, Carl will clear the course with SGNC, 24th, at 6:30 PM. Carl offered to host this meeting at his including dates and times for classroom usage. home in Normal.  Carl indicated that he thought it wise to review key holder  Tim will speak with Lee Green about acquiring TCAA policy with respect to SGO given our pending Introduction Internet domain control from Mike Rogers now rather to Amateur Astronomy course. It was agreed to create a than waiting until June when we could lose control of sub master key that opens only SGO and that a master key WWW.TCAA.US. will open SGO, PSO, and the storage locker. Bob will see to the changes. It was further agreed that a key holder fee of The meeting was adjourned at 7:45 PM. $10 will be assessed for sub master key holders. Carl was authorized to disseminate sub master keys to those who Respectfully submitted, completed training through his Introduction to Amateur Carl Wenning, Secretary Astronomy course.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

Motions approved via email: The two motions below were proposed Carl Wenning on  I move that we submit Carl's name and The OBSERVER January 16th and seconded by Tim Stone on the same date: for the 2016 AL Mabel Stearns award.

 I move that the proposed work to remove shelving on Motion passed by a vote of three Yes and one abstain on the ground floor of PSO, to “dry wall” and insulate the March 6, 2016. ground floor room as appropriate, install a pocket door, rewire as appropriate, cover exposed framework of SGO Additional action taken by the Board on the ground floor up to the second floor landing, as well as the ceiling of the second floor landing if the Treasurer Duane Yockey informed the Board via email anonymous donor sees fit to do so. that dues for our membership in the International Dark-Sky  I move that changes in the telescope placements Association were due. It was suggested that we might want outlined in an email by Tim Stone on January 15, 2016, to consider making this an ongoing expenditure rather than be approved. That is, that the 17” along with its mount one that requires annual approval. and pier be moved to PSO and placed in the south The following motion was made by Tim Stone and position; that the PSO 10” along with its mount and pier seconded by Carl Wenning after an NCRAL meeting on be moved to the west position; that the PSO 11” along February 16, 2016, when a quorum of Directors was present: with its mount and pier be moved to SGO, and that the H-alpha solar telescope be co-mounted alongside the  I move that membership and dues payment to the 11” in SGO. International Dark-Sky Association (IDA) be made an ongoing annual expenditure until such time as the TCAA Both motions were approved unanimously on January 18, Board of Directors would vote to discontinue TCAA’s 2016. affiliation with IDA.

Motion by Tom Weiland, seconded by Bob Finnigan, on The motion was approved on February 16, 2016. March 5, 2016:

NCRAL 2016 PLANNING COMMITTEE NOTES

Immediately following the March 22nd Board of Directors meeting, the NCRAL 2016 Planning Committee met for a period of about 15 minutes to address the state of readiness for the April 29/30 event. The following points were made:

 Carl noted that both online and paper registration continue without any problems. Registrations are coming in day by day and the process seems to be working properly. Our count is not as high as we would like to see, but the final pre- registration process will continue for another month yet.  Another promotion will be made very soon to remind people about the Early Bird registration deadline on March 31st.  The nearly finalized 8-page program was then shown, and gone through line-by-line to see if there are any updates, problems or unmet needs. The following were indicated:

- At this point in time we have 5 contributed talks and two discussion topics for the Friday evening “unconference.” - Bob indicated that another sponsor has come forward. We are expecting a donation from the Santa Barbara Instrument Group. Carl noted that whiteboardsUSA.com will contribute additional support beyond the 24-page eclipse guide. Bob continues to work with others for possible sponsorships. - Tables and chairs are needed for registration and displays. - We still need to arrange for A/V tech support, security, and custodial services. - We don’t know anything about door prizes as we’ve not heard from Paul recently. (A follow-up email indicated that he is currently in the process of calling around to distributors and manufacturers seeking door prizes.) - Lisa and Mark Boulware will be responsible for refreshments during the SGNC visit as Tom will not be available.

 Carl will be contact HCC officials to make final arrangements.  Carl will make available a draft program to Lee for posting on the NCRAL 2016 website.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

ASTROBITS

 Mark Boulware and Carl Wenning have signed up for Skynet training and will be working with Vivian Hoette to conduct additional TCAA outreach. They hope to work with kids from 4-H and Scouts…  Carl Wenning continues to develop his Astronomical Bucket List observing program. Since last month the northern bucket list has expanded from 450 objects to 632! Carl continues to find ways to identify the best objects in the sky worthy of observation. Of course, this list will be winnowed down substantially as he continues to observe and qualify each object for inclusion in the final list. Here is what the northern group – the basic list – now contains: 22 asterisms, 10 asteroids, 32 bright nebulae, 59 constellations along with their 2nd magnitude and brighter stars, 51 double stars, 2 dwarf planets, 34 elliptical galaxies, 43 globular clusters, 1 irregular galaxy, 74 open clusters, 11 planetary moons, 7 planets, 35 planetary nebulae, 1 quasar, 196 spiral galaxies, 15 stars (not bright but unique in some other way), 28 variable double stars, 9 variable stars, and the sun and moon.  The club’s 8” Coulter Odyssey telescope (shown right) has been put on temporary loan to Peter Kates and his two sons Daniel and John. Before it could be loaned out, however, it had to be cleaned up and re- collimated. The telescope has been in the club’s possession since at least 1996 when Rebecca Wenning used it to complete the initial level of the AL’s Messier observing program. Thanks for Carl Wenning and Allan Saaf for getting the telescope back into good operating condition again.  Bob and Tim spent the afternoon prior to the March POS working in Prairie Sky Observatory making updates and fiddling with wires as they are wont to do. Thanks and a tip ‘o the hat for the ongoing dedication to keeping PSO as fit as a fiddle. Tim later reported, “We are wiring permanent 12v power supplies on all the piers to replace the multiple adaptors and bricks supplying 12v to individual items. This will result in far fewer wires dangling about, and much more reliable operation.”  Several TCAAers observed the total solar eclipse on March 8th using the Exploratorium’s live Webcast from Woleai, Micronesia. It’s an amazing thing though that Tom Weiland spent two years as a Peace Corps volunteer on Woleai Atoll where the production crew was observing this event. Tom noted that the video crew had set up on WWII Japanese airstrip he remembers well. Known to be viewing this feed were TCAA members Tom Weiland, Tim Stone, Carl Wenning, and Brad Welch.  The Sky This Week is a regular feature of the Astronomical League. This 5-minute program covers the moon, visible planets, comets, and interesting stellar features. Take a look at https://www.astroleague.org/SkyThisWeek  Did you know that the Astronomical League is now on Facebook? Just do a search on “Astronomical League.” They are also on Twitter at @AstronomyLeague.  Posts are being made quite regularly on the TCAA’s Facebook page. Recent posts been “reaching” anywhere from 200- 600 viewers within 24 hours of their posting.  A new feature has made its way into this issue of The OBSERVER. Your editor will attempt to provide a New Member Profile (see below) every time we get a new member. Of course, this will depend upon the willingness of new members to share information about themselves. We hope they will. If you are a new member and would like to be featured in a new member profile, please write a brief introductory paragraph or two and email it along with a good image of yourself to our newsletter editor [email protected]. See Adam Giebelhausen’s profile below as the first example. The next time you see Adam, be certain to greet him and welcome him to the club.

My name is Adam Giebelhausen and I joined TCAA last September. I learned about the group in Mark Cabaj’s astronomy course at Heartland Community College, where I am studying computer networking. I’ve been interested in astronomy since I was a kid; in fact, up until last month I was still NEW MEMBER using the 4.5” Meade reflector my grandparents gave me when I graduated middle school. Originally I’m from the suburbs of Chicago and relocated to Bloomington about 6 years ago. PROFILE I’m having a lot of fun getting reacquainted with the night sky now that I’m away from the glare of the city. Eventually I’d like to learn astrophotography and how to use the club’s guided scopes, but for now I’m working on the Astronomical League’s Messier program so that I can earn my stripes, so to speak. I would like to extend a big thank you to those of you who have stopped to teach me how to star hop and read a star chart, you have been a great help, there are a lot more stars out at Sugar Grove than I’m used to. I’m glad I found a group of people so willing to share their knowledge and experience, and look forward to having the opportunity to help out where ever I can.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

 The TCAA Astronomy Giveaway! drawing associated with the public observing sessions this year will provide some lucky winner with a Celestron 114 LCM computerized telescope with a database of 4,000 objects. One of our club’s generous anonymous donors is making this telescope available. TCAAers are reminded that they are eligible to enter this free drawing by completing a Giveaway! registration form during each of our public observing sessions. One registration per family is permitted each month.  Bob Baer, a friend of Carl Wenning and a member of the SIUC Physics Department, just returned from Indonesia where he both viewed and imaged to totally eclipsed sun. Here we have a “quick look” image from totality showing the streamers of the corona as well as a significant prominence. Unfortunately, much of the detail in the original image has been lost due to the compression process used to create the PDF through which The OBSERVER is electronically distributed. Image credit: Citizen CATE Experiment, image data by Bob Baer and student assistant Sarah Kovac.  One of our members wants to try out a new avocation as a short story writer and has asked that “The Eclipse” be published in this issue of The OBSERVER. This is the author’s first attempt at writing a short story. The author wishes to remain anonymous and has chosen the pen name of “Jo Lewis”. The author has indicated that you should feel free to post constructive comments on the TCAA yahoogroups listserv. This will help the author become a better writer. Look for “The Eclipse” later in this issue of the newsletter.  Despite the scattered clouds and roving rain showers, on the evening of March 16th Bob F. and Carl W. were able to get in a bit of practice time for the upcoming Introductory Astrophotography course to be taught sometime this summer. They were able to use the club’s Canon Mark II adapted camera to photograph M42 despite the presence of the nearby moon. They tried out a variety of software to control the camera. Either a wired hand controller or a laptop computer running the appropriate software can now be used to control the camera. The importance of having a small class was clearly evident due to the intense amount of one-on-one work required for proper training. Carl is now thinking that the class might run three nights with additional time for individual mentorship scheduled separately. Keep you eyes open on The OBSERVER for this course that should not be confused with Introduction to Amateur Astronomy that will begin some time in June.  It looks as though we might have a new exchange of astronomy club newsletters with a Carbondale group. Details will be provided when they become available.  On March 20th, Tim Stone finished the power wiring on the 20" telescope, and put it through a full system test. The next night he lubed the 17" RA worm gear assembly. He then did a calibrate and guide test, and remarked that the telescope “now guides better than it ever has in my memory.” Thanks, Tim, for the constant work efforts on behalf of the TCAA. Not to be overlooked is the constant assistance and support by Bob Finnigan and Justin Meyer.  Greg Koos, retiring director of the McLean County Museum wrote the TCAA recently to thank us for our contributions to making McLean County a more rewarding place to live by helping people learn. He wrote a personal note at the end of his letter, “Thanks for serving our star-gazing community!” It’s nice to know that we are appreciated.  Tim and Justin Meyer continued to prepare the PSO’s 17” and 20” telescope on March 23rd. They spent time working on flats using the Flatman screens. Both telescopes should both be fully operational very soon. The reader might recall that the 17” was moved recently from SGO to PSO, and that the 20” needed firmware updates and such.  Bob met with Robin the carpenter at SGO on March 24th to begin the second round of work with the remodeling of the first and second floor rooms.  President Tim Stone has, with the approval of the Board of Directors, nominated this newsletter’s editor for the Astronomical League’s Mabel Sterns Award for excellent in service. TCAA editors Mike Rogers and Jean Memken were recognized with the inaugural Mabel Sterns Award in 1988.

(AstroBits continues on page 11.)

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

MARCH 2016 POS WELL ATTENDED

March POS - Despite an overcast sky and an air future TCAA events. There were 18 who signed up for the temperature of around 40°F, 49 members and guests TCAA Astronomy Giveaway! that is being made possible showed up for the first SGNC public observing session of the again this year due to the generosity of a club member who year on March 5th. Tim Stone gave a 30-minute talk about wishes to remain anonymous. There were 25 TCAAers in Messier 42 and the surrounding region. He spoke about both attendance: Tim Stone, Bob Finnigan, Carl Wenning, Dave scientific and aesthetic features of the nebula, and used Osenga, Tom Weiland, Dave Peters, Bryce & Mark Heiniger, many of his photographs taken in the TCAA observatories. Brian Barling, Lisa & Dick Wentzel, Lee Green, Duane Yockey, Following his talk, attendees visited PSO and SGO to examine Paul Pouliot along with Eve and Amber, Justin Meyer, Mike the telescopes. They also had a chance to visit the with his son Steve Starasta, Adam Giebelhausen, Eric Clifton, remodeled room on the ground floor of SGO where they and Peter Kates with his two sons Daniel and John. were able to see a wider array of photographs taken with ISU Adventure Club – The ISU Adventure Club that had club equipment. The evening’s warm up program featured planned a field trip to SGNC for an observing session on an updated looping PowerPoint presentation developed by Tuesday, March 15th, canceled due to threatening weather Lisa Wentzel to highlight aspects about light pollution and conditions.

SKYNET JUNIOR SCHOLARS

Mark Boulware and Carl Wenning attended the Skynet Junior Scholars training program at Yerkes Observatory in Williams Bay, WI, March 17-20. They did so in response to an invitation by TCAA member and long-time Yerkes Observatory staff member Vivian Hoette. During this four-day NSF-sponsored event, Mark and Carl learned how to work with youth using research quality optical and radio telescopes around the world. The event began with a reception at the observatory on Thursday evening. Following introductions and a brief overview, everyone had a chance to tour the observatory during a scavenger hunt. Among the many activities that evening was observing through the historic 40” refractor. Staff member Dan Koehler turned the telescope to the first quarter moon, and we observed it at 380X. The field of view was only about 13’ of arc (the moon is 30’ approximately). Considerably narrower fields of view were also available at 475X (10.4’) and 633X (9.5’). This is as would be expected for a 1- meter aperture, 19,000mm focal length (f/19) telescope. That evening we also had a chance to view through the observatory’s 24” reflector. We would visit the 41” reflector used with Skynet the next night. During Friday evening, Mark imaged M104 for 27 seconds using the Prompt5 optical telescope located at Cerro Tololo Inter-American Observatory in Chile. Later, his image (shown in Figure 1) became the subject of study by Mark, Carl, and another teacher from Reading, PA. As Mark noted, “For the optical observation, the objective was to calculate the flux as a function of distance from the center of M104 (Sombrero Galaxy). Afterglow software was used to gather angular distance and flux data. Selected data points were obtained over the dust/gas disk with the center point automatically calculated.” The data points were centered inside the green circles show as Figure 1 (see next page). Carl used the Yerkes 41-inch optical reflector at about the same time to image Messier 87. He was later able to produce color image of the galaxy with the well-known jet due to its central black hole clearly evident. © 2016 TCAA 9 All rights reserved.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

Also on Saturday, both Mark and Carl used the National Radio Astronomy Observatory (NRAO) 20-m radio telescope in Green Bank, WV. Mark did a “daisy” scan of 3C48 to localize this well-known quasar in Triangulum. Carl mapped the Cassiopeia A supernova remnant (SNR). Using a clover trace to localize the object first, he then programmed the radio telescope to map the object. Using a side-to-side and bottom-to-top scan, he was able to develop a contour map of the object shown in Figure 2. He used 1024 channels centered on a frequency of 1550.0 MHz. That image was automatically translated by Skynet to produce the visual counterpart shown here in Figure 3. Mark and Carl are now working with 4H leaders at the U of Figure 1. Mark's image of M104, the Sombrero Galaxy in Virgo I Extension office in Bloomington to assemble a group of students with whom to work. If you have a 4H student (grades 6-8) in your family who might be interested in Skynet Junior Scholars, please contact Carl at [email protected]. Stay tuned for additional details.

Figure 2. (shown to the left) Contour map of SRN Cassiopeia A.

Figure 3. (shown to the right) Optical counterpart of the Cassiopeia A SNR.

GET READY NOW FOR MAY 9TH TRANSIT OF MERCURY ~ By Carl Wenning ~

Did you know that the planet Mercury will cross over the face of the sun (transit) as seen locally on Monday, May 9, 2016? Some of you might recall observing the similar transits of Venus in 2004 and 2014. We hope that you will do the same thing for the transit of Mercury. Mercury is tiny in comparison to Venus, and much farther away. As a result, it will be very difficult to see the little planet without the use of a telescope. In addition, due to the intense brightness of the sun, special solar filters will be necessary to view this event safely. I first attempted to observe a transit of Mercury back in November 1973. I looked for the planet using solar filters but without telescopic aid. I never saw the planet and therefor missed its transit. Transits of Mercury will occur only two times between now and 2032, if you miss observing this transit you will have to wait until November 2019 to view the next one. Fortunately, the 2016 event will last over 7 hours, staring shortly after sunrise and continuing into early afternoon as seen from Central Illinois. Plans for a possible TCAA public observing session have yet to be work out. Stay tuned to this "channel" to learn more about this rare event and how you might join us to view it. This is the time – right now – to purchase the necessary solar filter for your telescope if you do not have one. You’ll need one that fits over the front of your telescope. Avoid eyepiece solar filters as they absorb the heat of the sun and can shatter explosively subjecting the eye to the intense rays of the sun. On the day of the transit, the sun will rise at 5:45 AM. First contact will occur only a few minutes later, at 6:11 AM. Mid transit will occur at 9:57 AM. Due to daylight saving time, the sun will transit the meridian at 12:52 PM. Final contact will take place at 1:42 PM. The duration of the transit will be 7 hours, 31 minutes. More information about the transit of Mercury will appear in the May issue of The OBSERVER. Also, we should at that time have detailed information for you about when and where the TCAA will host its observing session for the general public.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

ASTROBITS (Continued from page 8.)

 Mark Boulware and Carl Wenning met with 4H leaders on March 24th to set up a special interest group for Skynet Junior Scholars. See the accompanying article about their workshop at Yerkes Observatory in Wisconsin March 17-20.  Thanks to hard work by Bob Finnigan, NCRAL 2016 now has several corporate sponsors: Woodland Hills Camera & Telescope, Santa Barbara Instrument Group, and Astro-Physics, Inc. The owners of whiteboardsUSA.com also will contribute additional support.  On March 24th and 25th work resumed on remodeling the “welcome center” on the ground floor of Sugar Grove Observatory with mudding and taping of the newly installed wall panels. We now have a working white light in the dome. Thanks to Bob Finnigan for supervising the work.  A spontaneous “star party” occurred at SGNC on Friday, March 25th. Bob Finnigan, Tim Stone, Justin Meyer, and Tony Cellini busied themselves with imaging in PSO. Brian Barling and Carl Wenning busied themselves with visual observations in SGO. Pete, Daniel, and John Kates visited both locations and spent a bit of time with Carl learning to use the 8” Coulter Odyssey loaner scope from the parking lot. Tim managed to get in three 5-minute shots of the cometary companion P/2016 BA14 PANSTARRS as it streaked by Earth at 15.8 magnitude. It is shown here in three composite images taken at irregular intervals. The comet was moving at a rate of about 19.6”/minute. Each five- minute streak is therefore about 98 arc seconds long. The images were taken with the 16” f/3.9 AG Optical telescope. Bob was imaging on the evening of March 25th as well. He used the 20” f/6.8 CDK PlaneWave telescope to photograph the Eskimo Nebula in Gemini (NGC 2392). The image shown to the left is a single 900-second Hα channel shot. The image was taken with the new SBIG 16803 camera and includes flats and darks.  Pope Benedict XVI, in his 2012 Easter vigil homily, made reference to deleterious effects of light pollution. While he goes on to make a religious point, his use of the analogy of light pollution is interesting. Quoting, “Today we can illuminate our cities so brightly that the stars of the sky are no longer visible. Is this not an image of the problems caused by our version of enlightenment? With regard to material things, our knowledge and our technical accomplishments are legion, but what reaches beyond, the things of God and the question of good, we can no longer identify.” The editor thanks Fr. Timothy Sauppé of Westville, IL, for pointing out this quote. Fr. Sauppé, you might recall, is the head of the Dark Vermillion Skies initiative.  Tim Stone continued re-wiring the 17” on March 26th. It is now fully operational. He was diligently taking pictures with the telescope on the evening of March 28th and took the club’s first images of M67 using Johnson B and V filters to allow Carl Wenning to do accurate photographic photometry.  Carl Wenning did a complete polar re-alignment on the mount of the SGO 11” telescope on March 28th. He got the telescope operating with absolute precision in the western sky. Upon rolling over to the eastern sky (German equatorial mount) he found that the telescope has a substantial “orthogonality” error. This occurs when the telescope’s optical axis is not parallel to the telescope’s declination plane. This error will be remedied only with shims properly placed between the telescope and the mount. Work will resume when the sky clears.  On March 28th, Bob Finnigan got SGO’s locks rekeyed in preparation for the Introduction to Amateur Astronomy course to start some time in May. The cost of doing so was over $100. The sub master key holder fees will be used to pay for this update. The update allows “master” key holders access to both observatories whereas the sub master key to be given to those successfully completing telescope user certification will open only SGO.  Tim Stone snagged this image of Comet 252P (shown to right) on April 1st at about 2:30 am. This image consists of two 600-second green light sub images stacked. The short tail is clearly visible. The coma is about 0.5 degree in diameter. © 2016 TCAA 11 All rights reserved.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

IMAGE OF THE MONTH (Continued from page 1.)

The view from any of these galaxies toward their neighbors must be breathtaking. Simply calculating the angular separation between M66 and NGC 3628 and applying trigonometry yields a distance between them of somewhere around 330,000 light years. That's about twice the distance from us to the Magellanic Clouds. It's amazing to consider what astronomers in these galaxies must be able to see. On the other hand, it's quite possible that encounters like this make conditions for life extremely rare. The starburst activity that's clearly present in M66, with its subsequent supernova barrage, may sterilize virtually the entire galaxy. A multitude of background galaxies are also visible in this image. Galaxies perhaps as faint as 21st magnitude pepper the image, beckoning to us from vast distances. These galaxies are part of a complex of clusters and superclusters (clusters of clusters) that form the filamentary structure of the universe itself. These galaxies have garnered at least as much attention as the nearby bright galaxies in our immediate neighborhood.

TCAA GUIDES COMING

With the approval of the Board of Directors, the club is now producing a number of member guides for the TCAA membership. This is in response to both the club’s 5-year plan and requests of the membership during last summer’s club survey. Five of the six guides have been fully drafted and are currently under review and revision. A sixth guide is under development. Additional guides will be developed as warranted. All guides will be available for download through the club website once they are finished. The names of the guides are as follows:

 Guide #1 – INTRODUCTION TO AMATEUR ASTRONOMY (50+ pages) – This guide addresses the basics that everyone needs to know in order to become as amateur astronomy. It deals with the use of eyes, binoculars, and telescopes to view the night sky. It should not be mistaken as a textbook in astronomy. This will serve as a handbook for the upcoming course by the same name. Recently, several sections were added for using SGO and its telescopes.  Guide #2 – MEMBERSHIP AND BENEFITS (14 pages) – Even long-time members do not knew everything they need to know about membership in this club. Many benefits are overlooked and this publication does what it can to clearly illustrate the benefits of membership.  Guide #3 – ASTRONOMY AS A HOBBY (9 pages) – Why is it that we don’t attract as many amateur astronomers as we would like? Our club has lots of great benefits, and it’s more the just lack of knowledge of benefits. Part of the problem today stems from the fact that many people don’t understand the meaning of a hobby and the benefits derived from it.  Guide #4 – THE ART OF SKY INTERPRETATION (14 pages) – Interpreting the sky requires more than just standing in front of a group of people and talking. If it were that easy, there would be many more speakers in our club! There is an art of sky interpretation, and this guide describes it. Even if one doesn't intend to give public talks, this guide provides a wealth of information about what can be seen in the sky with the unaided eye.  Guide #5 – COORDINATING OBSERVING SESSIONS (3 pages) – While coordinating observing sessions might appear to be an easy task to those who attend them, there is considerable background work associated with both public and members- only sessions. Consider hosting an observing session and use this guide to assist.  Guide #6 – INTRODUCTORY ASTROPHOTOGRAPHY (under development) – With the arrival of the new Introduction to Amateur Astronomy course (see below), it is likely that a number of our members will want to learn how to use the club’s specially modified digital single-lens reflex (DSLR) camera to image objects in the night sky using the SGO observatory’s Celestron 11” HD telescope.

The author is now seeking your assistance in reviewing these publications. Tom Weiland, Allan Saaf, and Ken Kashian have already risen to the occasion having reviewed several of the draft publications. You need not be an expert in the subject matter areas to serve as a reviewer. We are looking for everything from errors to incomplete information to unanswered questions to unclear statements. If you are interested in participating in this review process, please contact the author directly at [email protected].

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

INTRODUCTION TO AMATEUR ASTRONOMY

In response to comments in last summer’s online membership survey and a good experience with Universe Sampler during the autumn, Carl Wenning will be teaching Introduction to Amateur Astronomy beginning during June. Formerly called Universe Sampler II, this new course will be a 3-class series meeting on a weekly basis. Classes will run from 7-9 p.m. on Saturdays with observing afterward weather permitting. Supplemental telescope training sessions will be added as necessary. If ever you have been hoping and waiting for the TCAA leadership to provide the necessary training and support to assist YOU in becoming an amateur astronomer, your wait is over. Take advantage of this course now. You need not have participated in last autumn’s Universe Sampler course to participate in this new course.

It’s time for the TCAA’s non-observing members to get out of their armchairs and become practicing amateur astronomers!

Participants will receive a binder with the recently created 50- page TCAA Guide #1 – Introduction to Amateur Astronomy – as part of the course. Attendees will learn about some 35 different topics including types of telescopes, eyepieces, finder scopes, mounts, finding objects in the sky, magnification, field of view, focal ratios, focal lengths, eye relief, light-gathering power, seeing and transparency, limiting magnitude, observing practices, polar alignments, telescope collimation, and much more. Participants will learn how to independently operate the club’s Celestron 11” HD “goto” telescope housed under the dome of Sugar Grove Observatory (SGO). Qualifying participants also will receive a key to SGO providing unlimited access. Registration will be limited to only 6-7 adult TCAA members in good standing (18 years and older with dues paid). This is so because much of the telescope training will be done using SGO – a privilege of membership. Also, there is limited viewing space in SGO that precludes a larger class enrollment. Parents wishing to help their children learn how to use the SGO’s telescope should plan on learning the procedures first, and then teaching their children afterward. If the course does not fill to capacity by the announced deadline, older children will be admitted along with at least one fully participating parent or adult guardian. This course is not advisable for children under 12 years of age due to the sophistication of much of the subject matter. Individuals participating in the course (will have to pay the full registration fee of $25; other members from the same household must pay a partial $15 fee. There will be only one set of course materials per household. The fees will provide for course materials and payment for use of the nature center building at SGNC where classes will be taught. Admission will be on a first-come, first-served basis for qualified applicants. Those qualifying for the use of the SGO’s Celestron 11” HD telescope will need to pay an additional one-time $10 key holder fee. This fee will be used to offset the cost of rekeying the SGO door with sub master locks and keys. To register for this course, complete the online application as soon as possible but not later than April 15th. Again, enrollment is on a first-come, first-served basis for qualifying applicants. You may access the online application by visiting this case-sensitive URL: https://goo.gl/gwUUfh Your instructor will be Dr. Carl J. Wenning who holds degrees in astronomy, and is an Astronomical League Master Observer with more than 50 years of viewing experience. He has been a member of the TCAA for 37 years, and is a well- known astronomy popularizer and author. He directed the ISU Planetarium from 1978 – 2001. Please note that this is the first time this course will be offered and hopefully not the last. Whether it is offered a second time will depend upon demand this time around. Do not delay in taking this course now if at all interested.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

THOUGHTS FROM LIFE AT SEA: PART 2 ~ By Carl Wenning ~

While contemplating the distance to the horizon at sea Columbus knew full well from his travels by ship that Earth last February, over the course of several days of sitting on was spherical. He could see the ships cross over the horizon deck I saw many ships come and go. The way they came and and note that it occurred in every direction (precluding Earth went was of a particular nature. It is not as though they from being, say, a cylinder). There is no other logical approached my ship coming from a point at infinity where I conclusion that could be drawn other than the Earth is could see a whole ship the complete time; rather, ships spherical in shape. always appeared superstructure first and hull second as they There was additional evidence visible to our forefathers came over the horizon toward me. They disappeared over prior to the invention of the telescope to prove that Earth the horizon in reverse order – hull first. This was nowhere was at least roughly spherical in nature. Because this is so, more evident than one day when I watched an empty oil Christopher Columbus was able to get funding from the tanker pass by. Crown of Spain for starting his 1492 trip to Cathay (China) It was riding quite high in the water due to being empty, and Cipango (Japan) “traveling east by going west.” (Recall and the white superstructure was clearly evident (especially that the telescope was not invented until more than a with binoculars) long before the red hull was. This is so century later.) Consider the additional evidence available to because Earth’s surface is curved. As the tanker came Columbus to support his claim of a spherical Earth: Earth’s Shadow – During a total lunar eclipse Earth’s shadow falls upon the full moon. That shadow at the moon’s distance always appears to be a portion of a circular disk. This occurs no matter what time of night the eclipse occurs – from sunset to sunrise. Only a spherical object can produce a shadow that is always in the shape of a disk. There is no other logical conclusion that could be drawn other than the Earth is spherical in shape.

toward me from a point over the horizon, the tanker rose higher into my field of view. It disappeared in reverse order as shown here. Now, how far away was the horizon in my situation? Consider from the first article in this series the refined formula for the distance to the horizon as a function of the height of the observer’s eyes above sea level:

푑푘푚 ≈ 3.86√ℎ푚

I viewed this oil tanker coming and going from a vantage point about 20m above sea level. Ergo, the horizon from my perspective was some 17km distant. While binoculars helped me make this observation, they were not available to the ancients. This limitation is easily overcome however. Changing Elevation of Polaris – The North Star’s If one observes ships crossing the horizon with the eyes elevation in the sky is a function of latitude. The relationship just above sea level, then the horizon is much nearer, and between the two is essentially (but not exactly) the same. ships won’t appear as small when crossing that horizon. The elevation of pole star Polaris is roughly equal to the Standing on a beach with the eyes only 1.7m above sea level, observer’s latitude. As an observer nears the North Pole, the horizon is only 5km (3mi) distant. When this close, the Polaris approaches the zenith; as an observer nears the shape of a ship is still readily discernable. terrestrial equator, Polaris approaches the northern horizon. Large ships with tall sails could easily be seen to cross Indeed, when crossing over the equator going south, Polaris over the horizon hull first in the days before the invention of disappears from the sky entirely, dipping below the northern the telescope. These appearing and disappearing acts horizon. This occurs at all longitudes. There is no other occurred then as now in all directions. Indeed, Christopher © 2016 TCAA 14 All rights reserved.

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logical conclusion that could be augured likewise. The argument is still valid today. There is drawn other than the Earth is no other logical conclusion that could be drawn other than spherical in shape. the Earth is spherical in shape. Opposite Seasons – The Now, there are many other proofs for Earth’s spherical scholar Venerable Bede nature. (Technically it’s an oblate spheroid.) Do you know (672/673 – 735 AD) argued that what they are? Can you explain them? opposite seasons in the Next month I’ll deal with the “dip of the horizon.” Do northern and southern you have any idea what this is? Navigators know, and I’ll use hemisphere indicated a it as an introduction to the art of celestial navigation that is spherical Earth. The differences conducted with the use of a sextant and an accurate in the lengths of day and the timepiece. differing paths of the sun across

A VISIT TO JOHNSON SPACE CENTER ~ By Carl Wenning ~

At the end of our Central American cruise this past the moon. I was perhaps a bit dismayed while people February, Carolyn and I stopped at the Johnson Space Center whizzed by the specimens seemingly unaware of their in Houston to take in the historical sights and to see the significance in human history. recently opened Independence Plaza. While seeing a Saturn Much harder to miss was the stack seen in V moon rocket resting on its side is always impressive, what Independence Plaza. Just opened a couple of days before, was even more impressive to me were sights of large moon we were among the first to actually tour a full-blown rocks and the full-scale shuttle trainer – Independence – mockup of the Independence orbiter trainer. It was amazing mounted atop the Boeing 747 that was used to ferry shuttles to see what one would actually encounter sitting in the across the nation after their return from space when they cockpit of the real thing. Everything on board was identical landed in California. to an actual orbiter. The only thing missing were the engines. The Lunar Samples Vault was at the head of the list of Seeing the orbiter and the 747 mated and then being able to best attractions for me. I can remember our moon landings walk around and beneath them will be something that I will very well and have always been attracted to the lunar never forget. samples. I’ve even had sample disks from NASA 2 or 3 times, Unfortunately, we didn’t have the time to make it out to but nothing prepared me for the large specimens we saw – Mission Control, but I suspect that it is rather much like breccia, anorthosite, and basalt. The specimens were huge – mission control at our local Challenger Learning Center. If typically 5-7 inches across, and for once gave me a real you've not been to either of these places, I recommend that impression about what the lunar surface is like. I couldn't you add them both to your list of “must visit” places to go. help but reflect on the years of work and piles of money that were expended to bring these national treasures back from

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

FOR SALE: 17.5” DOBSONIAN TELESCOPE

Rich Tennis of the Peoria Astronomical Society has a large, portable telescope for sale. Rich notes, “The Coulter mirror was evaluated at above average by expert telescope builder Dan Joyce. The focal ratio is f/4.5. The secondary mirror is 4.5” diameter (minor axis). Has a Williams 2” or 1.25” focuser (Crayford style). The case was rebuilt in the style of the Obsession telescope. Wood is Finnish marine quality birch with Teflon bearings. Mirror fan not connected. No dew removal system. Sky Scout included for use as an object locator. Will consider refractor of equal value in trade. Located near Eureka, IL. Asking $2,100.” If interested, phone Rich at (309) 467-3597 or email him at [email protected].

SUN FUNNEL MATERIAL AVAILABLE FOR PURCHASE

Tom Weiland and Dave Osenga will be presenting on how to build a sun funnel at NCRAL 2016. The funnel requires an 8” by 8” piece of rear screen projection material from an online provider. Only a few sections were needed for the presentation from the larger 2’ by 2’ piece (minimum order size) that had to be purchased from the provider. Six unused 8” by 8” pieces of material are available for purchase at the cost of $5 each. All other parts for the funnel can be purchased locally from hardware stores. Contact Tom Weiland at [email protected] if interested.

SGNC WISH LIST

Donating new or gently used items is an excellent way to make an important contribution to Sugar Grove Nature Center. Take a look at their wish list for items and services that will enhance programs, beautify the grounds, or make life a little easier for volunteers and staff. Their full wish list can be found at the following URL:

http://www.sugargrovenaturecenter.org/forms/wish%20list%202015.pdf

SGNC’s current list of urgent needs consists of the following: sugar (for making hummingbird food); grape jelly (all- natural, for the orioles); oranges (for the orioles); 45-gallon trash bags; birdhouses, and garden tools (pruners, loppers, shovels, rakes). Please do consider helping out.

ESTIMATING THE DISTANCE OF MESSIER 67

~ By Carl Wenning ~

On March 22nd I took several 30-second photographs of Cancer the Crab’s Messier 67 using Johnson B and V photometric filters. The images were obtained using Dark Sky Observatory’s remotely controlled 17” telescope in Boone, NC. Using batch processing to do photometry of the two images, I was able to get uncalibrated b and v magnitudes for 148 cluster stars. By using a reference star whose B and V magnitudes are known, I was able to plot the uncalibrated data as shown on the next page. The main sequence is somewhat evident, but would be even more evident were more stars measured in the high color index portion of the spectrum. These late class stars are quite dim, and I plan to work with PSO

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

equipment to obtain better images in the future that include many more faint stars than were observable in the above image. Nonetheless, I didn’t want to waste the opportunity to at least estimate the distance of M67 using main sequence fitting. Consider the apparent magnitude of the cluster’s main sequence at color index value of 1.0 in the color-magnitude diagram below. The apparent magnitude at this color index is about 13.5. If one reads the absolute magnitude at this color index on an H-R diagram, one gets about 6.0. The difference is due entirely to the distance of M67. The difference, m – M, is the distance modulus, and the related equation can be used to determine the distance of the cluster.

푚 − 푀 = −5 + 5푙표𝑔10푑

푚 − 푀 + 5 = 푙표𝑔 푑 5 10

13.5 − 6 + 5 = 푙표𝑔 푑 5 10

2.5 = 푙표𝑔10푑

푑 = 102.5 = 316 푝푐 = 1030푙푦

This is approach has a number of flaws as the current best estimate is around 800 parsecs. For instance, vignetting is clearly evident in the above image of M67. Neither darks nor flats were used to calibrate the image. This can be a source of the inaccuracy. With our own equipment we can eliminate this problem. Again, not having enough data for the dim stars makes it a bit hard to get a good feel about the best location of the main sequence. And, too, I’m still learning how to use the photometer for measuring brightness (and probably took a few too many short cuts as this is a pilot project). With the equipment we have on hand at Prairie Sky Observatory (including Johnson B and V filters), there is no question in my mind that we can do today the same job as professionals back in the 1970s using the Mount Palomar 200” telescope! I’ve recently started another observing project as well – determining the mass of Jupiter using photographs of the Galilean moons. I was able to do this with my telescope and a stopwatch to determine the separations of the moons and planet several years ago. I got within 3% of today’s accepted value. I should have a write up available about the photographic approach for the May newsletter assuming I don’t run out of time preparing for NCRAL 2016. Photographing the planets (a single 0.1-second image using the prompt5 telescope in Chile is shown above), variable star studies, and the rotation periods of faint asteroids aren’t far behind. I hope to tackle these and other pilot projects this summer as I work to write up procedures for Skynet Junior Scholars.

TCAA ON FACEBOOK AND TWITTER

Did you know that the TCAA is on both Facebook and Twitter? We encourage users of both social networks to follow the TCAA to see what the club is doing. If you have not yet joined us on Facebook, you are missing important reminders about astronomical events posted several times weekly. You can find us on Facebook by searching either TCAA or Twin City Amateur Astronomers. We can be found on Twitter at @TC_Astro. You may access our sites without actually being a member of Facebook or Twitter (though you might need the Facebook cookie). Merely use your browser to search for these terms. If you don’t want to miss out on additional reminders and other club information, be certain to subscribe to both. People are seeing more of our Facebook page due to the numerous weekly posts. To the left is information about recent activity on Facebook, including the number of “reaches” per day (averaging about 238/day) as well as activity by the time of day. Data are from March 6-12. © 2016 TCAA 17 All rights reserved.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

2016’S SECOND PUBLIC OBSERVING SESSION APRIL 2ND

This year’s second public observing session will take place from 8-10 PM on Saturday, April 2nd, at Sugar Grove Nature Center. Bob Hoy will present a talk titled Jupiter and its Moons. First observed by Galileo in 1609, the largest planet in the solar system has an amazing variety of moons. Learn how to observe these moons and their motions. Each public observing session includes the following:

 Lecture about the featured object or topic. This 30-40 min. presentation, held in the SGNC picnic shelter, includes images of and details about the featured sky object or topic as well as information about other interesting objects that might be viewed that evening.  Sky tour using a laser pointer. We step out under the stars to point out the major constellations and planets, and to designate the location of the featured celestial object for the evening if appropriate.  Telescope observing session. We use a wide variety of telescopes at ground level to observe the wonders of the heavens. The Sugar Grove Observatory has an “open house”. Visit to see what’s happening there.

Here is a list of other things to know about our public observing programs:

 Programs will be held even in the event of an overcast sky; active rain, however, will cause a cancellation of the event. On cloudy evenings the presentation will be given and tours of the Sugar Grove and/or Prairie Sky observatories will be available. Additionally, various images taken by TCAA astrophotographers will be shared via computer display in one of the observatories.  Please dress very warmly during cooler months. These are outdoor events; none of the buildings we use are heated.  Please be very careful when driving into and out of the Sugar Grove Nature Center parking lot. At all times there are people, including small children, walking from place to place in the dark. Please park so that your headlights are aimed away from the picnic shelter and telescopes.  You may bring along a flashlight if you wish, but be certain to cover the lens with a red filter so that observers’ dark adaptation isn’t adversely affected. Please aim your flashlight at the ground only. Also, please leave pets at home.

You may download the schedule of 2016 POS events at the following URL: http://www.tcaa.us/Download/POS_2016.pdf

REMAINING PUBLIC OBSERVING SESSIONS FOR 2016

The TCAA Board of Directors has approved the following schedule and topics for the 2016 public observing sessions at SGNC. In addition to the presentations described below, we will conduct a laser-guided sky tour and have telescopes set up for viewing if the sky is clear. These events are now listed on Facebook. Sign up for them if you want to be reminded.

May 07 Galaxies Galore (Carl Wenning) 8:30 – 10:30 PM The best time of year to view galaxies is when the Milky Way is not in view. May is the month without the Milky

Way so now is the best time to look. Learn where to find galaxies galore using a set of binoculars.

Jun 11 Moons of the Solar System (Lee Green) 9:00 – 11:00 PM The variety of the solar system’s many moons is simply astonishing. Join us on a trip around the solar system as we examine the moons of Earth, planets, dwarf planets, and even asteroids.

Jul 02 Mars and Saturn (Lee Green) 9:00 – 11:00 PM Without a doubt, Mars and Saturn are the two planets that most capture the general public’s imagination. Mars –

a potential harbor of life – and Saturn – the ringed wonder – will astonish as you learn more.

Aug 06 Globular Clusters of the Milky Way (Carl Wenning) 8:30 – 10:30 PM Stars of our galaxy come individually, in binary systems, in small groups, in open clusters, and in titanic globular

clusters. Join us as we describe the largest star systems within the Milky Way – some containing 100,000+ stars.

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

Sep 03 The Heart of the Milky Way Galaxy (Dave Osenga) 8:00 – 10:00 PM Recent studies have shown that the heart of our galaxy – like most other galaxies – is a seething, writhing mass of

stars about to meet their doom as they are swallowed by a massive black hole.

Oct 01 Fading Glories of the Summer Triangle (Tim Stone) 7:00 – 9:00 PM Stars live out most of their lives as in rather stable fashion. However, near the ends of their lives they become

unstable. They swell and redden, and eventually end their lives in violent outbursts – some yet visible today.

THE ECLIPSE ~By Jo Lewis ~

He had lugged his telescope to in this clearing – the only suitable In this moment of wonder and the clearing in the woods intent on one he could find within a reasonable awe, he stumbled into his telescope viewing this solar eclipse in solitude. walking distance of his car. and over the precipice it fell. He “For once,” he though, “I want to From this vantage point he could didn’t know what to do – turn his view an eclipse without having to be see the sun rising upward in the blue eyes to the soon-to-be-eclipsed sun bothered by people asking to look eastern sky. The opening in the trees or watch his treasured telescope through my telescope.” Besides, this to the south was assured by the vast careen into the growing darkness eclipse was special; it was a total expanse below him. “What better below. In the distance he could see eclipse of the sun. He had never seen location could I have chosen?” he the leading edge of moon’s umbra an eclipse like this before and asked himself. moving quickly from west to east decided to go it alone. Watching carefully through the across vast expanse before him. It was the 21st of August and he eyepiece he noticed the moon Totality was upon him. He was was supposed to back at the intruding upon the sun. It was 11:54 stunned, almost stupefied. university today for the first day of a.m. when he first noticed it. For the Taking only a moment to grasp classes. He didn’t care; he wanted to next 1 hour and 27 minutes he his now desperate situation, he see this eclipse. He had heard his watched the constant progress of the turned his eyes to the heavens grandfather speak glowingly of an moon across the face of the sun. All knowing that his telescope was gone eclipse that he viewed once in the the while the pair drifted westward forever, but so would be this chance rugged Gapse Peninsula of Canada across the sky. He was waiting to view this total solar eclipse he had back on July 10, 1972. Now, he had impatiently for his 2 minutes and 40 been waiting for since childhood. traveled to Shawnee National Forest seconds in the moon’s umbral Turning his eyes to the heavens in southern Illinois to watch this shadow that would be the source of he saw the hazy glow of the corona important first-in-a-lifetime event. his “story telling” for future beginning to extend outward from This summer wasn’t really all generations. the sun’s limb. A few bright that much unlike the one his As totality approached, the air prominences here and there were grandfather spoke about. It was hot temperature dropped. Still, his hands outlining the solar limb. Each was and humid, and the chatter of insects were wet with perspiration. The seemingly separating the lacy, was in the air. The incessant buzzing, stress of waiting was just killing him. delicate lines that formed the corona. chirping, and clicking in the As darkness descended upon the Despite what had happened, he undergrowth of the woods gave him, earth from the moon’s umbra, the was now lost in a sense of wonder he felt, the same experience his diamond ring was just about to and awe. “Wow, WOW!” was all he grandfather would have had up in occur. He looked up from his could say. He kept repeating himself eastern Canada 45 years earlier. At telescope and looked momentarily at over and over despite the fact that least he didn’t have to deal with the sun with his unprotected eye. The there was no one to hear him. black flies. diamond ring and Bailey’s beads By the time central eclipse had He had positioned his telescope were amazing! He whopped and arrived, at 1:23 p.m., the corona was precariously close to the edge of a howled and flailed about like a mad now visible to its maximum extent. sheer drop off. He had no choice but man. Fortunately, he still had his to place it there. The trees were tall binoculars and turned them to the

Vol. 41, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2016

sky. He saw the corona now how fast 2⅔ minutes could come and Looking into the brightening extending outward nearly a solar go. The diamond ring reappeared this abyss before him, he could now see diameter, and the loops of several time on the other limb of the sun. In his shattered telescope down below. pink prominences were clearly another 1 hour and 25 minutes the It would remain there for years to evident. eclipse would be over, and life on come as silent testimony to his As quickly as it had started, the earth would return to normal. observation of the total solar eclipse. eclipse ended. He was amazed at

HOWTIMEFLIES

The Twin City Amateur Astronomers was founded in 1960 through the efforts of John & Bertha Kieviet. Over the years, newsletter editors David B. Williams, G. Weldon Schuette, Garry Skinner, Jim Moncher, Mike Rogers & and Jean Memken, Rebecca Wenning, and Erin Estabrook (as well as other contributors) documented the efforts of the club. Now, TCAA Editor and Historian Carl Wenning continues that effort and provides monthly updates about the history of the club going back in intervals of 40, 25, and 10 years. Details about all mentioned events will be found in either the publication Twin City Amateur Astronomers: 1960-2010 or in the archive of The OBSERVER found on the TCAA website.

40 Years Ago: April 1976 – TCAAers have been enthralled with the two-tailed appearance of Comet West in the eastern morning sky. It is now departing the inner solar system. The club continues with official Messier observing sessions at Bob Finnigan’s observatory in Downs, IL.

25 Years Ago: April 1991 – The club hosts an Astronomy Day event in the Central Court of College Hills Mall. This display was described as “very professional looking” according to a local newscaster. The TCAA is sponsoring StarDate twice daily on ISU’s WGLT-FM radio thanks to the generosity of Mike Rogers & Jean Memken.

10 Years Ago: April 2006 – TCAAers Roy & Barb Ostberg, Sharon MacDonald, and Carl Wenning return from their expedition to view the March 29th total solar eclipse in the Mediterranean Sea. They observed the eclipse just east of Crete. Duane Yockey and Carl attend the 2006 NCRAL meeting in Appleton, WI.

TCAA TREASURER’S REPORT – APRIL 2016

The April 2016 Treasurer’s Report was not available as of April 4th when this publication was finalized. It is expected that two reports will be included in next month’s issue of The OBSERVER. The delay was caused by the transition to a new club treasurer, the first such transition in nearly two decades.