April 2020 OBSERVER

Home , 37 Tauri, 56 Sagittarii, Beta Capricorni, Epsilon Tauri, Iota Capricorni, Kappa Tauri

THE OBSERVER OF THE TWIN CITY AMATEUR ASTRONOMERS

Volume 45, Number 4 April 2020

INSIDE THIS ISSUE:

1«Editor’s Choice: Image of the Month – NGC 1893 2«President’s Note 2«Who Wants to Get Together on ZOOM? 3«Calendar of Celestial Events – April 2020 3«New & Renewing Members/Dues Blues/E-Mail List 4«This Month’s Phases of the Moon 4«This Month’s Solar Phenomena 4«TCAA Calendar of Events for 2020 5«Minutes of the March 10, 2020 BoD Meeting 6«Updated TCAA 5-Year Plan (2020-2024) 7«AstroBits – News from Around the TCAA 8«April 2020 with Jeffrey L. Hunt 15«TCAA Image Gallery 15«Renewing Your TCAA Membership 15«Crater Wargentin and Mira 17«Public Viewing Sessions for 2020 17«Did You Know? 18«TCAA Treasurer’s Report as of March 29, 2020 18«TCAA Active on Facebook

The TCAA is an affiliate of the Astronomical League as well as its North Central Region. For more information about the TCAA, be EDITOR’S CHOICE: IMAGE OF THE MONTH – NGC 1893 certain to visit the TCAA website at tcaa.us/ This image of NGC 1893 was taken by Scott Wade using the new filter wheel and filters on the QHY 600 camera mounted the Visit Astroleague.org for additional 17” PlaneWave at PSO. The image consists of four 600-second information about the League and its subs in three spectral regions: Hα, OIII, and SII. The images were numerous membership benefits, taken on the evening of March 24th. As flats have no yet been including observing programs. prepared, the illumination across the field is somewhat irregular. NGC 1893 is an open cluster of about 4,600 stars in the constellation Auriga. It is about 12,400 light years away. The star Also, visit the NCRAL website at cluster is embedded in the HII region IC 410. ncral.wordpress.com for information Paraphrased from Wikipedia, the cloud of glowing hydrogen about our North Central Region. Find gas is over 100 light-years across, sculpted by stellar winds and out about our next Regional radiation from the embedded star cluster. The interstellar convention during May 2020. cloud was formed a mere 4 million years ago. Notable near the 11 o'clock position in this wide, detailed view are two relatively dense streamers – potentially sites of ongoing star formation. These so- called cosmic tadpole shapes are about 10 light-years long.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

PRESIDENT’S NOTE The OBSERVER Our dreary skies have continued is the monthly electronic newsletter of Twin through the equinox and on into the City Amateur Astronomers, Inc., a registered 501(c)(3) non-profit educational spring season. It’s all made drearier by organization of amateur astronomers inter- the current Shelter-in-Place situation. ested in studying astronomy and sharing However, astronomers have a leg up in their hobby with the public. this “lockdown” climate. We have

equipment to maintain, observing logs TCAA OFFICERS & CHAIRPERSONS to straighten up, planning to do for a

President, Director, & Property Manager future cloud-free evening, and reading Tim Stone 309-531-2401 to catch up on the latest astronomical [email protected] news. I, for one, have been working

Vice President & Director/Membership Coord. with my solar spectrum data, and have Tom Willmitch 309-846-2423 even had time to write an article for President Tim Stone [email protected] The OBSERVER.

Treasurer & Director/Registered Agent You might not consider yourself to be much of a writer, but I assure you, you Dave Osenga 309-287-0789 can write an email and send it to Carl Wenning, our newsletter editor. Tell us about [email protected] your observing goals for 2020, a memorable observation you’ve made, or anything 4th Director/Assistant Property Manager like that. We’d love to hear from our members in this slow time, and now you don’t Scott Wade 309-310-2464 have “I don’t have time” as an excuse! Come on! [email protected] Like the rest of the world, the club’s activities have been impacted by the 5th Director current pandemic. We have already cancelled our Public Viewing Session for April, Sunil Chebolu 678-896-5967 and we will evaluate when we should resume as things progress. If you haven’t [email protected] subscribed to our new email list, you should do so to receive the latest club Secretary/Historian/Editor information. Subscription is simple. Visit https://groups.io/g/tcaa to do so. Carl J. Wenning 309-830-4085 In closing, let me just say please, stay safe and well. This virus is serious, and [email protected] nothing to be trifled with. We will get through this and, when we do, the stars will Astronomical League Correspondent still be there. We want you to be there, too. Robert Finnigan 309-846-9533 [email protected] Still yearning for clear skies, Technology Coordinator Tim Stone, President Justin Meyer 630-649-0611 [email protected]

Webmaster Lee Green 309-454-7349 WHO WANTS TO GET TOGETHER ON ZOOM? [email protected] Teachers of online courses regularly make use of a free application called Lighting Educ. & AL Observing Club Coordinator Lisa Wentzel unlisted number ZOOM to converse “face-to-face” as it were with their students using computers, [email protected] tablets, and smartphones. You can download a free copy of ZOOM (https://zoom.us/download) and join a TCAA conversation. The OBSERVER Following a notification on Groups.Io (see next page to Carl J. Wenning, Editor learn how to subscribe), the first such online meeting was Submission deadline two days before held on the evening of March 28th. Participating in the event the end of each month. were Dave Osenga, Sunil Chebolu, Deva Chatrathi, and Carl Wenning. In an hour-long meeting, they discussed a variety MEMBERSHIP DUES of things as diverse as astronomy, photography of birds, Individual Adult/Family $40 and mathematics. Full-time Student/Senior $25 Using ZOOM is as easy as clicking on a hyperlink, so watch for these notices. (Senior status equals ages 60+) Additional online events using ZOOM will be schedule from time to time. To receive To join, send your name, contact info, and your notifications, be certain you are a registered with Groups.Io. dues payment to Dave Osenga, TCAA Treasurer, 1109 N. Linden St., Normal, IL 61761-1471.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

CALENDAR OF CELESTIAL EVENTS – APRIL 2020 NEW & RENEWING MEMBERS

MORNING PLANETS (4/15): Mercury (☿), Mars (♂), Jupiter (♃), The following individuals have paid dues for new or Saturn (♄), and Neptune (♆) renewed memberships as of March 29, 2020. (Others who paid after that date will appear in the April 2020 EVENING PLANETS (4/15): Venus (♀) and Uranus (⛢) issue of The OBSERVER.)

The following table gives the date and time (24-hour clock) of Welcome! Welcome! Welcome! Welcome! Welcome! important astronomical events for this month. All events are given in Central Standard Time. New: None

Renewing: Roy Lawry Day Time Event Welcome! Welcome! Welcome! Welcome! Welcome!

01 04:21 FIRST QUARTER MOON 02 01:59 Pollux 4.9°N of Moon DUES BLUES

03 00:25 Beehive 1.3°S of Moon If you have received a “your dues are due” statement along with the email that brought you this 03 08:36 Venus 0.3°S of Pleiades issue of The OBSERVER, please remit your dues to Mr. 04 12:45 Regulus 3.9°S of Moon Dave Osenga, TCAA Treasurer, 1109 N. Linden St., 07 12:08 Moon at Perigee: 356909 km Normal, IL 61761-1471. Dues are currently $25 for seniors (60 years of age and over) and $40 regular. 07 20:35 FULL MOON 12 20:58 Moon at Descending Node SUBSCRIBING TO THE TCAA EMAIL LIST 14 16:56 LAST QUARTER MOON Welcome to the [email protected] group at Groups.io. 14 17:04 Jupiter 2.0°N of Moon This is a free, easy-to-use group email service set up for 15 03:26 Saturn 2.5°N of Moon the TCAA’s communication purposes. You can subscribe, visit your group, start reading and posting messages 15 22:33 Mars 2.0°N of Moon here: https://groups.io/g/tcaa 20 13:01 Moon at Apogee: 406463 km The email address for this group is [email protected]. After you successfully subscribe, please add this email 22 00 Lyrid Meteor Shower address to your safe sender list in your email client's 22 20:26 NEW MOON contacts, so emails from this list do not end up getting 25 21:34 Aldebaran 3.8°S of Moon classified as junk mail. Once subscribed, you can set your subscription 26 04 Uranus in Conjunction with Sun settings here: https://groups.io/g/tcaa/editsub. You can 27 11:54 Moon at Ascending Node opt to receive all messages in individual emails, collections of messages in a digest, a daily summary, or 29 08:19 Pollux 4.7°N of Moon only special notices. If you do not wish to belong to this 30 07:18 Beehive 1.6°S of Moon group, you may unsubscribe by sending an email 30 14:38 FIRST QUARTER MOON to [email protected]

If you have general questions about the group, check email [email protected]. For questions not answered http://www.astropixels.com/ephemeris/astrocal/astrocal2020cst.html there, contact the moderators of this group (Deva C., Tim EVENING SKY MAP S., and Carl W.) by emailing [email protected].

Click on the icon found here to access a current evening sky map along with a more detailed celestial events calendar.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

THIS MONTH’S PHASES OF THE MOON

First Quarter Full Moon Last Quarter New Moon Wed, April 1 & Thu, April 30 Tuesday, April 7 Tuesday, April 14 Wednesday, April 22

All moon phase dates are Central Standard Time. Moon phases for the 2020 calendar year can be found by clicking here. Images provided by J. K. Howell of the Champaign-Urbana Astronomical Society & used with permission.

THIS MONTH’S SOLAR PHENOMENA

In the table below, you will find times of sunrise and sunset along with rising and setting azimuths (Az), length of the day including the change from the previous day, start and end times of astronomical twilight, and the time of solar noon along with the elevation (El) of the midday sun. These data come from https://www.timeanddate.com/sun/usa/bloomington

2020 Sunrise/Sunset Day Length Astronomical Twilight Solar Noon Solar Dist.

April Sunrise (Az) Sunset (Az) Length Diff. Start End Time (El) MIL. MILES 1 6:38 AM (83°) 7:21 PM (277°) 12:42:23 +2:39 5:05 AM 8:55 PM 12:59 AM (54.5°) 92.908 11 6:22 AM (78°) 7:31 PM (282°) 13:08:40 +2:35 4:45 AM 9:08 PM 12:56 PM (58.2°) 93.173 21 6:07 AM (73°) 7:41 PM (287°) 13:34:01 +2:28 4:27 AM 9:22 PM 12:54 PM (61.7°) 93.438

TCAA CALENDAR OF EVENTS FOR 2020

Date Event Speaker/Coordinator(s) Location Times April ??? TCAA Social Tom Willmitch CANCELED* April 25 Public Viewing Session Carl Wenning CANCELED* May 1-2 NCRAL 2020 Northern Cross Science Fdn. CANCELED* May 2 Astronomy Day (Spring) Tom Willmitch TBD TBD May 23 Public Viewing Session SPEAKER NEEDED SGNC 8:45-10:45 PM June 20 Public Viewing Session Sunil Chebolu SGNC 9:00-11:00 PM July ?? TCAA Summer Picnic TBD In-town Park? TBD July 18 Public Viewing Session SPEAKER NEEDED SGNC 9:00-11:00 PM August 22 Public Viewing Session Mark Cabaj SGNC 8:15-10:15PM September 19 Public Viewing Session Sandullah Epsicokhan SGNC 7:30-9:30 PM September 26 Astronomy Day (Autumn) Tom Willmitch TBD TBD October ?? TCAA Social Tom Willmitch? ISU Planetarium? TBD October 17 Public Viewing Session Lee Green SGNC 7:00-9:00 PM

* CANCELED: COVID-19, the Coronavirus, continues to take its toll, and now on amateur astronomy. Numerous public events have been canceled both locally and across the nation as a result of this serious health risk. Under the best medical advice available and following the recommendations of the Center for Disease Control (CDC), the TCAA supports “social distancing” in an effort to prevent the spread of COVID-19. Stay tuned to media and this newsletter for updates and details.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

MINUTES OF THE MARCH 10, 2020 BOD MEETING

President Tim Stone called the meeting to order at the We are looking forward to several possible State Farm Wenning residence at 6:30 PM. In attendance were Tom donations of $500 for volunteer work by employees – most Willmitch, Scott Wade, Sunil Chebolu, Bob Finnigan, and Carl notably Dave Osenga, Lee Green, and Scott Wade – who Wenning. Dave Osenga arrived 10 minutes after the start of complete 40 hours of service in a calendar year. Dave further the meeting. Absent were Lisa Wentzel, Justin Meyer, and noted that our bank recently sent the club’s new credit card Lee Green. A quorum was present. Attention was first turned to an incorrect address and that a new one will be issued. to officer and chair reports. The following matters of Old Business were then As president, Tim noted how well the Annual Meeting had addressed: gone and gave accolades to all who participated in its • Carl has plenty of 2020 PVS brochures that need to be planning and presentation. As property manager, Tim noted distributed. Please contact him if willing to help with the that the observatories are doing well, but that in order to distribution process. The ISU Planetarium and SGNC are align the 24” at WO, clear skies are needed – something that fully stocked at this time. has been infrequent of late. Bob noted that a new filter • wheel and filters are being acquired for work with the QHY Deva Chatrathi was not able to be present at the meeting 600 color camera at PSO as the current system is vignetting to talk about how progress with the new TCAA website is with the full-frame camera. V.P and Member Coordinator going. Carl assured everyone that Deva is making progress Tom noted that there are new programs at the ISU and will have something to share soon.

Planetarium, and that something will be arranged for the • There was a brief discussion about recent use of the club’s membership social during April. Groups.Io email system and some weird machination with Carl as Editor/Historian/Editor had nothing of significance the old email group having been subscribed. This is to report other than to remind the Board that he will be disallowed and the link was removed by Tim as one of three moderators. We are no longer using Yahoo.Groups. “retiring” from his positions at the end of any current term. Bob, as ALCor, noted that we had recently received a The following matters of New Business were then communication from the AL national office that was addressed: forwarded to the leadership and important elements will be included in the newsletter. With Lisa Wentzel and Justin • The need for three chair positions were reviewed with the Meyer absent, there were no reports for AL Observing Clubs conclusion that all positions should remain, and that chairs or Technology Coordinator. should be replaced on an as needed basis. A new name Though absent, Webmaster Lee reported through an was proposed for one position and Sunil will contact this email communication that he will try his best to assist Deva individual to see if interested. Carl will provide the contact Chatrathi to get the new club website up and running. He information to Sunil. also provided a sequence of steps that needs to be • Officers and chairs were then appointed for 2020-2021 with the following results: completed to make a transition to the new site. These recommendations were forwarded to Deva. Lee further o President/Property Manager: Tim Stone noted the need to retain the ability for interested parties to o Vice President/Membership Coordinator: Tom Willmitch request outreach events for the community. Lee will o Secretary/Historian/Newsletter Editor: Carl Wenning maintain the current site for a period of time so that others o Treasurer/Registered Agent: Dave Osenga who might visit our “former” web pages can be forwarded to o A.L. Correspondent: Scott Wade the new web pages. Lee will gladly continue to serve as o A.L. Observing Clubs Coordinator: Lisa Wentzel website administrator until a new administrator – o Technology Coordinator: TBA (Sandullah Epsicokhan) presumably Deva – is named by the Board. o Webmaster: Lee Green Arriving at this time, Dave Osenga, gave a detailed • The club’s 5-Year Plan was reviewed and slightly revised Treasurers Report noting the following balances – checking with two important additions. The updated document will $1,017.14, savings $2,017.96, total $3,035.10. He noted that be published in next newsletter. expenses for the Annual Meeting exceeded income by about • $170 which was expected. He displayed draft letterhead for Carl brought up the idea of declaring the Meade 12” OTA the 2020-2021 term of the new Board and asked for “unwanted equipment.” Following a brief discussion, it corrections. He showed business cards that can be produced was agreed to exchange the OTA for a $500 donation to for those who want/need them. He has completed one of the club. Carl will promote this exchange with two the tax reports for the club, with another two in the offing.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

potentially interested persons, and later in the newsletter Planetarium. Carl, working with Tom, will spearhead this if the initial attempts are unsuccessful. effort. • Those assembled discussed the possibility of nominating a • The next meeting of the Board of Directors will take place TCAA member for the NCRAL Region Award. A member on Tuesday, May 5th, starting at 6:45 PM which is 15 was named, his activities discussed, and nomination minutes later than usual. This is because the host teaches recommended. The Board will pursue approval of the an evening class and that will delay the start of the person in question and will work with that person to meeting. provide the best possible nomination letter. Tim will Carl reminded members of the NCRAL Vision 2020 forward the nomination to NCRAL by the March 31st meeting May 1-2 in Port Washington, Wisconsin. Three deadline. TCAAers will be attending to the best of his knowledge. Carl • Those assembled discussed the possibility of applying for a also encouraged officers and chairs to review their job $250 NCRAL Affiliate Recruitment Grant. Attention was descriptions provided earlier. (NB. The event was later focused on the fledgling ISU Astronomy Club. Board canceled due to COVID-19.) representatives will work with ISU club president to forge The meeting was adjourned at 7:49 PM. a mentoring relationship with the goal of assisting members to become an observing club focusing on Respectfully submitted, “sidewalk astronomy” using the resources of the ISU Carl J. Wenning, Secretary

UPDATED TCAA 5-YEAR PLAN (2020-2024)

(As amended by the Board of Directors on March 10, 2020. New items appear in italic.)

Change the TCAA image from merely “amateur” to more professional: • Host higher profile events to which we invite high-caliber public speakers. • Provide training for professional observing programs (e.g., photometry, spectroscopy, search for supernovas and asteroids, color-magnitude diagrams, etc.).

Maintain our visibility with the general public: • Produce “press releases” for interesting astronomical events and assist the public with their observations. • Maintain our current efforts with social media. • Create a year-long calendar of events at the start of each year.

Increase our outreach to youth: • Continue with our photographic program for youth during public observing sessions. • Maintain our current level of presentations to schools and social groups. • Work with the ISU Planetarium to increase educational opportunities for families.

Improve membership services with the goal of increasing membership and participation: • Meet regularly in an informal setting to improve camaraderie. • Present classroom and laboratory-based astronomy courses with foci on observation and photography. • Increase efforts to grow membership to include greater diversity.

Interface with other astronomy-related organizations: • Work closely with the ISU Planetarium on activities of mutual interest and benefit. • Maintain our relationships with Astronomical League, International Dark Sky Association, Night Sky Network, etc. • Seek to establish a mentorship with the ISU Astronomy Club, including the use of an NCRAL Affiliate Recruitment Grant. • Prepare to host NCRAL 2023 with emphasis on “stars” including the April 2024 total solar eclipse.

Sustain our observatories: • Generate income (e.g., release of unwanted equipment, development of an “observatory endowment,” etc.) to pay for the long-term upkeep of club observatories.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

ASTROBITS – NEWS FROM AROUND THE TCAA

ó On Leap Year’s Day evening, February 29th, SGNC saw a bevy of activity involving amateur astronomers. The first clear and “warm” night in a long time (30°F) brought out four intrepid observers. While Deva Chatrathi and Carl Wenning busied themselves with telescope practice on Carl’s 8” CPC and Messier observing, Bob Finnigan and Scott Wade busied themselves with making sky flats and working with the QSY 600 photographic system. Unfortunately, the sky began to cloud over at about 8PM and the night drew quickly to a close. Deva was unable to complete the NCRAL Messier Marathon for winter, having fallen 7 objects short of the goal. He will try again. ó On March 6th, Tim Stone noted, “I acquired a new spectrum of Betelgeuse tonight, to compare with my prior spectrum of 12/21. Coincidentally, it was almost exactly the same altitude both nights. The spectrum tonight shows Betelgeuse as somewhat redder, which is not likely due to atmospheric effects given the same altitude. The quality of the two nights was similar in terms of transparency and seeing. Betelgeuse is definitely brightening, according to the AAVSO. This probably means it is expanding again, its increased surface area accounting for the increase in luminosity. Expansion would also cool the star, which would result in higher red-end and lower blue-end luminosity, which is what we see here. While I can't prove this is the cause of the difference, it's at least plausible to me. The red profile is 3/6/20 and the blue one is 12/21/19.”

ó Lisa Wentzel, writing from Europe on March 12th, drew attention to the following statement from Rockland Astronomical Society, hosts of NEAF: “Due to the Coronavirus COVID-19 pandemic, Rockland Community College, the location of the annual Northeast Astronomy Forum (NEAF) announced new restrictions today limiting public campus gatherings to no more than 50 people until further notice. Because of this development, the 2020 Northeast Astronomy Forum will be held virtually online instead of at Rockland Community College where it has been traditionally held for 29 years. NEAF The Virtual Experience will be held one day only on April 4th, attendees to this historic virtual online event will experience product demonstrations, door prizes, and amazing speakers that have made the Northeast Astronomy Forum legendary. Additionally, the Rockland Astronomy Club will reschedule NEAF at Rockland Community College later this year and NEAIC at the Crowne Plaza in conjunction with NEAF.” Stay tuned at https://www.neafexpo.com/ ó By action of the Board of Directors of the Twin City Amateur Astronomers, the TCAA has nominated member Lee Green for the 2020 NCRAL Region Award. The nomination was put forward by President Tim Stone just before the March 31st deadline. If Lee wins the award, it will be presented at the NCRAL Vision 2020 convention in Port Washington, Wisconsin on Saturday, May 2nd. Regardless of whether or not Lee wins this prestigious recognition, Lee is a winner in the club’s eyes already – as are all those who benefit from his dedicated efforts within the club! Congratulations Lee! ó As noted in the minutes from the March TCAA Board of Directors’ meeting, the club’s Meade 12” ACF optical telescope assembly (OTA) has been declared “unwanted property.” This is an exceptionally high-quality visual instrument, though tends to have a problem retaining focus as the temperate drops. This, however, would not be a problem for visual

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

observers who very frequently move from object to object and then refocus. None of those previously contact is interest in the instrument. It is available for a suggested donation of $500. Contact [email protected] if interested. ó On Monday, March 16, NCRAL announced the cancellation of NCRAL 2020 with the following statement from convention host Jeff Setzer:

Due to the COVID-19 pandemic and the social gathering bans that are in place, as well as our desire to keep our NCRAL friends safe, the Northern Cross Science Foundation regrets to announce the NCRAL VISION 2020 is now canceled. Refunds will be made in the coming weeks.

On the other hand, the Northern Cross Science Foundation is pleased to announce that we volunteer to host the NCRAL 2022 convention. Dates and information will be forthcoming should that offer be accepted by the NCRAL officers.

In the meantime, as we socially isolate to slow the scourge of the Coronavirus, we all look forward to attending the NCRAL 2021 convention in Green Bay, WI. ó Due to changes in schedules and plans, two openings for speakers have opened up in the May and July public viewing program schedule. Tim Stone will be unable to deliver his May 23rd talk Galaxies of the Spring Sky and Mark Boulware will be unable to deliver his July 18th talk Jupiter & Saturn. Replacement speakers are urgently needed. Please contact editor at [email protected] if you are willing and able to present either or both of these talks. Thus far, following repeated appeals through Groups.Io, no volunteers have stepped forward. ó The Wennings and Sharon MacDonald have been making regular observations of the International Space Station recently. Both have been posting notices on Groups.Io, with Carl posting detailed information regularly on the TCAA’s Facebook page. His posts also deal with the locations and motions of the moon and planets. Be sure to subscribe so you don’t miss anything. ó The TCAA has submitted an application for the NCRAL 2020 Affiliate Recruitment grant approved in concept by the club, the ISU Planetarium, and the ISU Astronomy Club. If granted, $250 will be set aside for the TCAA to spend helping the ISU Club members come up to speed as amateur astronomers, with the primary goal of helping them become active sidewalk amateur astronomers. They will start using planetarium telescopes to assist passersby with observations of celestial objects visible from campus. A full set of activities will begin next autumn assuming the TCAA is funded. ó Recent observations by some TCAAers have shown that the star Betelgeuse in Orion appears to have returned to its usual brightness by around the third week of March. Back in October, the start began to dim considerably and no one is quite sure why. While the star is a known variable, the degree of dimming was unprecedented leading many people to think that the star was about to go supernova. ó On the evening of March 29th, Carl Wenning viewed Venus in the daytime sky. Using the nearby moon and the moon-sun line as a guide, he was able to see Venus at 6:59 PM, 19 minutes prior to sunset. He might have seen it earlier were in not for the passing a small cloud bank.

APRIL 2020: MORNING PLANET PARADE AND VENUS WITH THE PLEIADES ~ by Jeffrey L. Hunt ~

At the beginning of twilight as April opens (about 5 a.m. twilight and the beginning of morning twilight – is about 8 CDT), the Bright Outer Planets (BOP)s shine from the hours long. In the evening sky, brilliant Venus is near the southeast. Mars is near Saturn and Jupiter is nearby. Bright Pleiades, at the end of evening twilight (about 9 p.m. CDT). Antares is low in the south, just west of the meridian. Sirius and Venus have nearly the same altitude in the Farther west, Spica is low in the southwest, at an altitude western sky. The Winter Congregation begins to make its last lower than Antares. Arcturus is higher in the sky in the west- stand in the west, as daylight lengthens and the weather southwest. The haunches and tail (Denebola) of the Lion warms. Sirius, Orion’s belt, and Aldebaran are nearly the remain above the western horizon. The Big Dipper is now same height above the western horizon. Procyon, Pollux, tilted down toward the horizon in the northwest, with its Castor, and Capella make an arc higher in the sky. The Pointers reliably pointing northward toward Polaris. slightly gibbous moon is below Pollux on April 1. Farther Cassiopeia is low in the northeast. The Summer Triangle is east, Leo continues to climb into the sky. It is high in the higher in the east, Vega over two-thirds of the way up in the southeast. Arcturus is about one-fourth of the way up in the sky. During the daytime, the sun reigns for about 12.75 east with the Big Dipper higher in the sky in the northeast. hours. Darkness – the interval between the end of evening Spica is low in the east-southeast.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

This is another busy month for planet activity. Mars southeast. Jupiter, nearly 19° up in the southeast, is 6.1° quickly moves away from Saturn and Jupiter, as Jupiter to the upper right of Saturn. Mars, 1.4° to the lower left of inches toward Saturn. In the evening sky, Venus quickly Saturn, is 7.3° to the lower left of Jupiter. In the starfield, moves past the Pleiades early in the month and farther into Jupiter is 1.6° to the lower right of 56 Sagittarii. One hour Taurus. after sunset, Venus is 0.9° below Alcyone. The gibbous moon (9.7d, 67%) is over 11° to the lower left of Pollux in dim Cancer. With a binocular notice that the moon is 3.4° to the upper right of the Beehive Cluster (M44, NGC 2632). In a week or so, when the absence of the moon’s brightness provides a darker sky during early evening hours, return to inspect the cluster. The moon returns to this part of the sky at month’s end. • April 3: One hour before sunrise, bright Jupiter (m = −2.2) is over 19° in altitude in the southeast. Mars, 1.9° to the lower left of Saturn, is 7.8° to the lower left of Jupiter. Saturn is 6.1° to the lower left of Jupiter. In the starfield, Jupiter is 1.5° to the lower right of 56 Sagittarii. One hour after sunset, Venus, 30° up in the west, is 0.3° to the lower left of Alcyone. Use a binocular to see this spectacular appearance of the brilliant planet with the prominent star cluster. Farther east, the moon (10.7d, 78%) is over 60° up in the southeast, over 12° to the upper right of Regulus (α Leo, m = 1.3). • April 4: One hour before sunrise, bright Jupiter is over 19° up in the southeast. The Giant Planet is 0.7° to the upper The Bright Outer Planets span 6.2° at the start of April. One left of Pluto (m = 14.3) for the first conjunction of three day after its conjunction with Saturn, Mars has passed both during this apparition of Jupiter. Because of the low bright giant planets. The three planets will not be this close altitude of both planets (Yes, Pluto is a planet in a historic again until 2040. sense), you’ll need a very large aperture telescope and a • April 1: One hour before sunrise, Jupiter (m = −2.1) is good finder chart to locate this most-distant world. Saturn nearly 19° up in the southeast. Saturn (m = 0.7) and Mars is 6.0° to the lower left of Jupiter. Mars (m = 0.7), 2.5° to (m = 0.8) are to the lower left of Jupiter, one day past their the lower left of Saturn, is 8.4° to the lower left of Jupiter. conjunction. Mars is 1.0° to the lower left of Saturn and The Red Planet is now the same brightness as Saturn, and the Ringed Wonder is 6.2° to the lower left of Jupiter. The it continues its eastward march. In the starfield, Jupiter is planetary trio spans 6.7°. Watch the span grow about 0.6° 1.5° to the lower right of 56 Sagittarii. One hour after each day. To view the trio this close, you’ll have to wait 20 sunset, Venus, over 30° up in the west, is 0.9° to the upper years. By month’s end the BOPs span over 24° as Mars left of Alcyone. This evening and for the next few evenings marches eastward. In the starfield, Jupiter is 1.6° to the Venus and Sirius (α CMa, m = −1.5) are at nearly the same lower right of 56 Sagittarii (56 Sgr, m = 4.8). Watch Jupiter altitude in the west at the end of evening twilight (about sneak past the star during the next several days. Use a 105 minutes after sunset). While Venus and Sirius are too binocular to see Jupiter in the starfield. The moon reaches far apart for technical comparisons of their brightness its First Quarter phase at 5:21 a.m. CDT. One hour after difference, the brightest star and the brightest planet are sunset, Venus closes in on the Pleiades. This bright planet the same altitude in the western sky. Sirius, Orion’s belt, is over 30° up in the west, 1.8° to the lower right of Aldebaran, and Venus are nearly in a horizontal line above Alcyone (η Tau, m = 2.8), the brightest star in the cluster. the western horizon. Farther east, the gibbous moon Through a telescope, Venus is nearly 26” across and 47% (11.7d, 87%), over 50° up in the southeast, is 4.6° to the illuminated, a thick evening crescent. The moon (8.7 days left of Regulus. past the New Moon phase, 57% illuminated), nearly 70° in • April 5: One hour before sunrise, Jupiter is over 19° in altitude in the south-southwest, is 6.3° to the lower right altitude in the southeast. It is 6.0° to the upper right of of Pollux (β Gem, m = 1.2). Saturn. Mars, 3.1° to the lower left of Saturn, is 9.0° from • April 2: Saturn rises 3 hours before sunrise. One hour Jupiter. In the starfield, Jupiter is 1.5° to the lower right of before sunrise, the planet parade continues in the 56 Sagittarii. Use a binocular to see the planet with the

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

star. Mars is 5.1° to the lower right of Beta Capricorni (β Cap, m = 3.0). One hour after sunset, Venus, over 30° up in the west, is 1.8° to the upper left of Alcyone. Through a telescope, Venus is an evening crescent, 46% illuminated and 27” across. In the east-southeast, the moon (12.7d, 94%) is nearly 9° to the upper right of Denebola (β Leo, m = 2.1). • April 6: One hour before sunrise, Jupiter, nearly 20° up in the southeast, is 5.9° to the upper right of Saturn. Mars, 3.7° to the lower left of Saturn, is 9.6° to the lower left of Jupiter. In the starfield, Jupiter is 1.5° to the lower right of 56 Sagittarii, while Mars is 1.7° to the lower right of Omicron Capricorni (ο Cap, m = 6.0). Use a binocular to track the movement of the planets as they pass the dimmer stars. Farther west, the moon (13.0d, 95%), nearly 60° up in the west, is 8.2° to the lower left of Denebola. One hour after sunset, Venus is over 30° up in the west and 2.7° to the upper left of Alcyone. Farther east, over 25° in altitude, the moon (13.7d, 98%) is over 7° above Gamma Virginis (γ Vir, m = 3.4). • April 7: One hour before sunrise, the moon (14.0d, 99%), The morning planets are equally spaced along the ecliptic over 10° up in the west, is 2.7° to the right of Gamma with Saturn midway between bright Jupiter and Mars, 5.7° Virginis (γ Vir, m = 3.4). Farther east, Jupiter is nearly 20° from each planet. up in the south-southeast. Saturn is 5.9° to the lower left • April 9: One hour before sunrise, Jupiter is over 20° up in of Jupiter. Mars is 4.3° to the lower left of Saturn and 10.2° the south-southeast. This morning, as Mars moves farther to the lower left of Jupiter. In the star field, Jupiter is 1.4° eastward, the three planets are equally spaced along the to the lower right of 56 Sagittarii. Mars is 2.1° to the lower ecliptic. Saturn is 5.7° from Jupiter and Mars. In the right of Omicron Capricorni. The moon is at perigee at 1:09 starfield. Jupiter is 1.5° below 56 Sagittarii. Mars is 1.9° to p.m. CDT, when it is at 221,771 miles away. One hour after the lower left of Omicron Sagittarii and 1.8° to the lower sunset, Venus, over 30° up in the west is 3.5° to the upper right of Upsilon Capricorni (υ Cap, m = 5.1). Use a left of Alcyone and 2.8° to the upper right of 37 Tauri (37 binocular to track the planets with their sidereal Tau, m = 4.3). From this evening until its inferior backgrounds. In the southwest, the moon (16.0d, 97%) is conjunction, Venus sets, on average, over 4.3 minutes 7.3° to the right of Zubenelgenubi (α Lib, m = 2.8). One earlier each evening. The difference starts slowly, but the hour after sunset, Venus, over 30° up in the west, is just pace picks up at the end of the apparition. Ninety minutes below a line that extends from Aldebaran (α Tau, m = 0.8) after sunset, the moon (14.7d, 100%), nearly 18° up in the through Epsilon Tauri (ε Tau, m = 3.5). Three hours after east-southeast, is over 8° to the upper left of Spica (α Vir, sunset, the moon (16.8d, 93%), nearly 7° up in the east- m = 1.0). The moon reaches its Full Moon phase at 9:35 southeast, is nearly 6° to the lower left of Zubenelgenubi. p.m. CDT. • April 10: One hour before sunrise, Jupiter is over 20° up in • April 8: One hour before sunrise, Jupiter is 20° up in the the south-southeast. The BOPs span 11.9°. The planet south-southeast. The BOPs span 10.8°. The other gaps: J – gaps: J – S, 5.7°; S (m = 0.6) – M, 6.2°. Saturn (m = 0.6), S, 5.8°; S – M, 5.0°. In the starfield, Jupiter is 1.4° to the again, is brighter than Mars, but likely not much of a lower right of 56 Sagittarii, while Mars is 1.6° below difference to our eyes. As Mars moves farther eastward Omicron Capricorni. Continue to follow the planets’ and Earth closes in, Mars brightens rapidly in the motions compared to the starry background with a upcoming months. In the starfield, Jupiter is 1.5° below 56 binocular. The bright full moon (15.0d, 100%), 17° up in Sagittarii, and Mars is 1.5° to the lower right of Upsilon the west-southwest, is 5.8° to the upper right of Spica. In Capricorni. The moon (17.0d, 92%) is 8.3° to the upper left the evening sky, Venus continues its trek through Taurus. of Zubenelgenubi. One hour after sunset, brilliant Venus, One hour after sunset, Venus, over 30° up in the west, is over 30° up in the west, is above a line that starts at 3.0° to the upper right of 37 Tauri. Two hours after sunset, Aldebaran and extends through Epsilon Tauri. The planet the moon (15.7d, 98%), about 10° up in the east-southeast, is 4.2° to the right of Kappa Tauri (κ Tau, m = 4.2). Through is over 12° to the lower left of Spica.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

a telescope, Venus is 29” across and shows a thick evening • April 12: One hour before sunrise, Jupiter, over 20° in crescent phase, 41% illuminated. Four hours after sunset, altitude in the south-southeast, is 5.6° to the upper right the moon (17.8d, 86%) is nearly 5° up in the east- of Saturn and 13.1° to the upper right of Mars. In the southeast. starfield, Jupiter is 1.5° below 56 Sagittarii and Mars is 1.6° • April 11: One hour before sunrise, bright Jupiter is over to the lower left of Upsilon Capricorni. Use a binocular to 20° up in the south-southeast. Saturn is 5.6° to the lower spot the stars near the brighter planets. The moon (19.0d, left of Jupiter and 6.9° to the upper right of Mars. The 76%) is 1.8° to the upper left of Theta Ophiuchi (θ Oph, m three planets span 12.5° along the ecliptic. In the starfield, = 3.2). In the evening, Venus passes 6.8° to the upper right use a binocular to see Jupiter 1.5° below 56 Sagittarii and of Epsilon Tauri. Kappa Tauri is nearly between Venus and Mars 1.4° below Upsilon Capricorni. The moon (18.0d, Epsilon Tauri. 85%) is 6.0° to the upper right of Antares (α Sco, m = 1.0). • April 13: One hour before sunrise, Jupiter is 21° up in the One hour after sunset, brilliant Venus, over 30° up in the south-southeast. The BOPs span 13.7°. The other gaps: J – west, is 3.9° to the upper right of Kappa Tauri. With the S, 5.5°; S – M (m = 0.6), 8.2°. In the starfield, Jupiter is 1.6° bright moon away from the evening sky, look for the deep below 56 Sagittarii, while Mars is 2.2° to the lower left of sky objects M81 (NGC 3031) and M82 (NGC 3034). Upsilon Capricorni. The moon (20.0d, 66%) is 1.2° to the Separated by 0.6°, these two galaxies can be found about upper right of Kaus Borealis (λ Sgr, m = 2.8), the star at the 60° up and a few degrees east of the meridian in the north. top of the lid of the Teapot of Sagittarius. In the evening They are observable simultaneously at low power and can sky, Venus (m = −4.7) reaches its maximum brightness appear in a 50mm finder. They are about 10° northwest of until May 10. The midpoint is April 27. While the planet Alpha Ursa Majoris (α UMa, m =1.8) – the Northern may grow brighter, as measured photometrically, our eyes Pointer in the Big Dipper – and 2.0° east of 24 Ursa Majoris likely cannot perceive the minute difference in brightness (24 UMa, m = 4.5). In his Celestial Handbook, Burnham during this duration. The planet reaches its latest setting recounts J.E. Bode’s observation notes of the galaxy; time 11:33 p.m. CDT, 243 minutes after sunset. This “[M81 is a] nebulous patch, more or less round, with a setting time continues until April 18. The planet continues dense nucleus in the middle” (p. 1985). The galaxy is a its travels through Taurus. barred spiral, classified Sb, with apparent dimensions that • April 14: One hour before sunrise, the moon (21.0d, 55%) are 21’ x 10’. Sometimes this galaxy has the moniker is over 20° up in the south-southeast. It is nearly midway “Bode’s Galaxy,” for he is the first recorded observer of from Nunki (σ Sgr, m = 2.0), in the handle of the Teapot of this object. In the Messier Album, Mallas describes the Sagittarius, to Jupiter. Jupiter is 5.5° to the upper right of observing characteristics of the galaxy, “In a 4-inch Saturn. Mars, about 16° up in the southeast in central refractor a beautiful object. As seen in that telescope, M81 Capricornus, is 8.8° to the lower left of Saturn. In the has the most strongly granular central region of any galaxy. starfield, Jupiter is 1.6° to the lower left of 56 Sagittarii. The outer parts are mottled and uneven in brightness and Mars is 4.0° to the right of Theta Capricorni (θ Cap, m = texture” (pp. 154-155). Walter Scott Houston, in Deep Sky 4.1). Use a binocular to track the planets’ motions relative Wonders, adds that the catalogued diameter of a deep sky to the stars. One hour after sunset, Venus, over 30° up in object is often misleading. “This implies that [M81 is] the west, passes 9.9° to the upper right of Aldebaran. nearly a Moon’s width-across, but the catalog • April 15: One hour before sunrise, the thick crescent moon measurements include faint extensions of the spiral arms (22.0d, 45%) is 3.3° below Saturn, 20° up in the southeast. that are not visible in amateur telescopes. Thus, observers This morning Jupiter is 5.5° to the upper right of Saturn will see an object that appears only about half as large. and 14.9° to the upper right of Mars. In the starfield, M81’s arms are wrapped tightly around its large core” (p. Jupiter is 1.8° to the lower left of 56 Sagittarii, while Mars 80). M81 is a fine example of a magnificent spiral. More is 3.3° to the right of Theta Capricorni. In the evening sky, features of the spiral structure are revealed with brilliant Venus gleams from the stars of Taurus. One hour increasing telescopic apertures. On the other hand, M82 is after sunset, it is over 30° up in the west, 4.3° to the right not sharply defined. Houston describes it as, “A spindle of of Tau Tauri (τ Tau, m = 4.3). Through a telescope, Venus is light 10’ long and relatively bright” (p. 81). If you’ve not 31” across and 37% illuminated, an evening crescent. (See observed through a telescope recently, now is the time to corresponding image next page.) shrug off the winter observing hiatus. Get outside to enjoy the larger galaxy show that is displayed this time of year now that the Milky Way and its treasures are lower in the sky.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

• April 17: One hour before sunrise, bright Jupiter is nearly 22° up in the south-southeast. It is 16.1° to the upper right of Mars and 5.4° to the upper right of Saturn. Among the stars, Jupiter is 1.7° to the lower left of 56 Sagittarii, while Mars is 2.0° to the right of Theta Capricorni. The crescent moon (24.0d, 26%), nearly 9° up in the east-southeast, is 3.2° to the lower right of Delta Capricorni (δ Cap, m = 2.8). One hour after sunset, brilliant Venus is 3.9° to the upper right of Tau Tauri. • April 18: One hour before sunrise, Jupiter (m = −2.3) is over 22° up in the south-southeast. The BOPs span 16.7°. The other gaps: J – S, 5.3°; S – M, 11.4°. In the starfield, Jupiter is 1.8° to the lower left of 56 Sagittarii. Mars is 1.4° to the lower right of Theta Capricorni. At this hour find a clear horizon to locate the crescent moon (25.0d, 19%), 5° up in the east-southeast. In the evening, one hour after sunset, Venus – nearly 30° in altitude in the west, is 3.9° to the upper right of Tau Tauri. • April 19: One hour before sunrise, Jupiter is over 20° up The moon joins the morning planet parade when it is 3.3° in the south-southeast. Saturn is 5.3° to the lower left of below Saturn. Jupiter. Mars is 12.1° to the lower left of Saturn. In the starfield, Jupiter is 1.8° to the lower left of 56 Sagittarii, At midmonth, the crescent moon joins the planet while Mars is 0.9° to the lower right of Theta Capricorni. parade in the southeastern sky as morning twilight begins Thirty minutes later, the moon (26.0d, 12%) is 5° up in (about 4:30 a.m. CDT). Reddish Antares is about 10° west of the east-southeast. A binocular will assist you in finding the meridian. The Teapot of Sagittarius is between Scorpius the planets in the starfield and the moon near the and the planetary activity in the southeast. Farther west, horizon. One hour after sunset, Venus, nearly 30° up in Spica is approaching the horizon in the west-southwest with the west, is 9.8° to the lower right of Elnath (β Tau, m = Arcturus over 30° to Spica’s upper right. The Summer 1.6), the Northern Horn of Taurus. Star maps frequently Triangle is well-placed in the eastern sky. Vega is over 70° in show the star shared with Auriga. In that constellation it altitude. Daylight now lasts nearly 13 hours, 30 minutes, and is cataloged as Gamma Aurigae. Watch Venus approach darkness has receded to 7 hours, 15 minutes. At the end of the star. evening twilight (about 9:15 p.m. CDT), brilliant Venus • April 20: One hour before sunrise, Mars, nearly 17° up in gleams in the western sky to the upper right of Aldebaran. the southeast, is 0.8° below Theta Capricorni. In the Orion and Sirius are farther south along the horizon. The arc brightening sky, use a binocular to see the star with Mars. of Procyon, Pollux, Castor, and Cappella stands higher in the Bright Jupiter is 18.0° to the upper right of Mars. Saturn is western sky. Farther east, the Sickle of Leo is at the meridian closer, 12.7° to the upper right of the Red Planet. Jupiter, and Spica is low in the southeast. Arcturus is about one-third in the starfield, is 1.8° to the lower left of 56 Sagittarii. of the way up in the sky above the east mark. The bowl of The moon is at apogee at 2 p.m. CDT, 252,564 miles away. the Big Dipper is approaching its highest point as it nears the In the evening, Venus, less than 30° up in the west, is 9.1° meridian from high in the northeast. Its Pointers reliably to the lower right of Elnath. Through a telescope, Venus pointing northward. Following the Pointers in the reverse is an evening crescent that is 33% illuminated and 33” direction takes you to Leo. across. • April 21: One hour before sunrise, bright Jupiter is nearly • April 16: One hour before sunrise, Mars is 10.1° to the 23° up in the south-southeast. This morning the BOPs lower left of Saturn. Mars, over 16° up in the southeast, is span 18.6°. Saturn is 5.2° to the lower left of Jupiter and 3.8° to the upper right of the crescent moon (23.0d, 36%). Mars (m = 0.5) is 13.4° to the lower left of the Ringed This morning the BOPs span 15.1°. The Jupiter – Saturn Wonder. Mars is again brighter than Saturn. In the gap is 5.4°. In the starfield, Jupiter is 1.7° to the lower left starfield Jupiter is 1.9° to the lower left of 56 Sagittarii, of 56 Sagittarii, and Mars is 2.6° to the right of Theta while Mars is 1.2° to the lower left of Theta Capricorni. Capricorni. In the evening sky, brilliant Venus, over 30° up One hour after sunset, brilliant Venus, less than 30° in in the west, is 4.1° to the upper right of Tau Tauri. altitude, is in the west. It is 8.5° to the lower right of Beta

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

Tauri. Venus sets at its northern most setting azimuth (309°). It sets here until May 14. • April 22: Jupiter rises at 2:00 a.m. CDT, 4 hours before sunrise. One hour before sunrise, Jupiter is nearly 23° in altitude in the south-southeast, 5.2° to the upper right of Saturn. Mars is in Capricornus, near Theta Capricorni, 14.0° to the lower left of Saturn. In the evening, one hour after sunset, Venus is about 28° in altitude in the west. This brilliant planet is 7.8° to the lower right of Elnath. Notice that Venus and Betelgeuse (α Ori, m = 0.4) – 25° to the left of the planet – have nearly the same altitude. • April 23: One hour before sunrise, bright Jupiter is 23° up in the south-southeast. The BOPs span 19.9°. Mars is 14.7° to the lower left of Saturn, that is 5.1° to the lower left of Jupiter. In the starfield, Jupiter is 2.0° to the lower left of 56 Sagittarii. Mars continues its eastward march among the stars of Capricornus. This morning it is 1.5° to the upper right of Iota Capricorni (ι Cap, m = 4.2). Use a binocular to locate Mars and Jupiter near these stars.

One hour after sunset, brilliant Venus, nearly 28° up in The crescent moon makes a pretty triangle with Venus and the west and heading for its quasi-conjunction with Elnath (Beta Tauri). Elnath, is 7.2° to the lower right of that star. The moon reaches its New Moon phase at 9:26 p.m. CDT. • April 26: One hour before sunrise, bright Jupiter is nearly • April 24: One hour before sunrise, bright Jupiter is over 24° up in the south-southeast. It is 5.0° to the upper right 23° in altitude in the south-southeast. It is 5.1° to the of Saturn that is 16.7° to the upper right of Mars. The upper right of Saturn. The Ringed Wonder is 15.4° to the planetary trio spans 21.6°. In the starfield, Jupiter is 2.1° upper right of Mars. The three planets span 20.5°. With a to the lower left of 56 Sagittarii, while Mars is 0.5° to the binocular notice that Jupiter is 2.0° to the lower left of 56 lower left of Iota Capricorni. One hour after sunset, Sagittarii and Mars is 0.8° to the upper right of Iota Venus, the crescent moon (4.0d, 14%), and Elnath, make Capricorni. In the evening, look for the young crescent a nice triangle. Venus, over 25° up in the west-northwest, moon (2.0d, 3%) about 30 minutes after sunset, over 10° is 7.1° to the right of the moon and 5.6° to the lower right up in the west. A binocular will help. The crescent is over of Beta Tauri. The moon is 6.7° to the lower left of Taurus’ 20° below brilliant Venus. As the sky darkens further, Northern Horn. Also notice that the moon is 5.0° to the look for Venus 6.7° to the lower right of Elnath. lower right of Zeta Tauri (ζ Tau, m = 3.0), the Southern • April 25: One hour before sunrise, Mars, over 17° up in Horn of Taurus. the southeast, is 0.2° to the lower right of Iota Capricorni. • April 27: One hour before sunrise, Jupiter is nearly 24° up Optical assistance helps see Mars’ close proximity to the in the south-southeast. The BOPs span 22.4°. The other star. Mars is 16.0° to the lower left of Saturn and 21.1° to gaps: J – S, 5.0°; S – M, 17.4°. Use a binocular to observe the lower left of Jupiter. The Jupiter – Saturn gap is now that Jupiter is 2.1° to the lower left of 56 Sagittarii, and 5.0°. Jupiter continues to inch closer to the Ringed faster moving Mars is 1.2° to the lower left of Iota Wonder. In the starfield, Jupiter is 2.1° to the lower left Capricorni. In the evening sky, the waxing crescent moon of 56 Sagittarii. In the evening, about one hour after (5.0d, 22%) is over 17° to the upper left of Venus and 0.8° sunset, Brilliant Venus, 27° up in the west-northwest, to the upper right of Eta Geminorum (η Gem, m = 3.3). sparkles from among the stars of Taurus. It is 6.1° to the Venus continues to close the gap with Elnath. This lower right of Elnath. Through a telescope, Venus is an evening the separation is 5.1°. The planet has an evening crescent, 36.0” across and 30% illuminated. The elongation of 40°, and it is midway between its greatest crescent moon (3.0d, 8%) is nearly 11° below the planet. elongation and inferior conjunction. Venus is at its With a binocular, notice that the moon is 0.2° to the right greatest illuminated extent. The illuminated portion of of Epsilon Tauri, the star at the top right of the “V” of the planet covers the largest area of the sky. (For a more Taurus. technical explanation of greatest illuminated extent, see https://tinyurl.com/venus-greatest-illuminated.) Visually,

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

Venus is mid-way through its interval of greatest • April 30: One hour before sunrise, Jupiter – over 24° up brightness. in the south-southeast – is 4.9° to the right of Saturn. The • April 28: One hour before sunrise, bright Jupiter, nearly Ringed Wonder is 19.4° to the upper right of Mars. The 24° in altitude in the south-southeast, is 4.9° to the upper BOPs span 24.3° along the ecliptic. In the starfield, Jupiter right of Saturn, that is 18.0° to the upper right of Mars. is 2.3° to the lower left of 56 Sagittarii. Mars is 1.2° to the The three planets span 23.0°. In the starfield, Jupiter is upper right of Gamma Capricorni. The moon reaches its 2.2° to the lower left of 56 Sagittarii. Speedier Mars is First Quarter phase at 3:38 p.m. CDT. In the evening sky, 1.9° to the lower left of Iota Capricorni and 2.4° to the brilliant Venus continues its trek toward Beta Tauri. This upper right of Gamma Capricorni (γ Cap, m = 3.5). In the evening the gap is 3.7°. Through a telescope Venus evening sky, brilliant Venus is over 25° in altitude in the displays an evening crescent, 25% illuminated, and 39” west-northwest, about 1 hour after sunset. It is 4.6° to across. The moon (8.0d), 52%), over 60° in altitude in the the lower right of Beta Tauri. The waxing crescent moon southwest, is midway from Pollux to Regulus. It is 6.5° to (6.0d, 31%), over 45° up in the west, is 8.7° below Pollux. the upper left of the Beehive Cluster. The moon was in • April 29: Saturn rises at 1:50 a.m. CDT, 4 hours before this region earlier in the month. Did you observe the star sunrise. One hour before sunrise, Jupiter is over 24° in cluster after the moon moved away? altitude in the south-southeast, 4.9° to the upper right of Saturn. Mars (m = 0.4) continues to move through As twilight begins at month’s end (4 a.m. CDT), the three Capricornus. This morning it is over 18° to the lower left Bright Outer Planets span over 24° in the southeastern sky. of Saturn, 1.8° to the upper right of Gamma Capricorni Farther west, Antares is low in the south-southwest and and 2.5° to the lower left of Iota Capricorni. Jupiter is 2.2° Spica is half Antares altitude in the west-southwest. Rusty to the lower left of 56 Sagittarii. In the evening, about Arcturus stands nearly half-way up in the west. In the east, one hour after sunset, brilliant Venus is over 25° up in the the Summer Triangle is high in the eastern sky. Bright Vega is west-northwest and 4.1° to the lower right of Beta Tauri. nearly 80° above the eastern horizon. Daylight now lasts Venus reaches its most northern celestial latitude, 4.8°, over 14 hours and darkness is reduced to about 6 hours, 30 continuing to set at its most northerly azimuth, 309°, minutes. Twilight lasts nearly 3 hours, 30 minutes, divided until May 14. Higher in the western sky, the moon (7.0d, equally between evening and morning. As evening twilight 41%) is nearly 8° to the upper left of Pollux. ends (about 9:30 p.m.), the First Quarter moon is in Cancer between Leo and the Gemini Twins. Brilliant Venus is low in the west-northwest, near Elnath – the Northern Horn of Taurus. Venus approaches the star next month before the planet plunges toward its inferior conjunction. The bright winter stars are beginning to disappear into the glow of twilight. At this hour, Sirius is less than 5° in altitude in the west-southwest. Appearing low in the west-northwest, Aldebaran has about the same altitude as Sirius. Betelgeuse, above the west mark, is about twice as high as Sirius. The arc of Procyon, the Gemini Twins, and Capella is above the trio of descending stars. Farther east, The Sickle of Leo is west of the meridian, but the tail – Denebola – is less than 10° east of the line that divides the rising stars from the setting stars. Spica, about one-third of the way up in the southeast, is to the lower left of the celestial lion, while Arcturus hangs nearly halfway up in the east-southeast. The classical pincers of the Scorpion – Zubenelgenubi and Zubeneschamali – are about 15° up in the southeast. Watch the celestial arachnid climb into the evening sky during the next month. On May 6, the bright moon appears to be captured in the creature’s The Bright Outer Planets span over 20° in the morning sky. claws. Deneb and Vega are low in the northeast at this hour.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

TCAA IMAGE GALLERY

M42/M43 BY PAC’S AL SHEIDLER – TCAAers might remember that several years ago PAC member Al Sheidler purchased a unwanted 10” LX 200 from the TCAA. He repaired the telescope’s electronics and has been using it successfully ever since. On March 1st he reported, “Last night a group of us got together at the Paul Castle Memorial Observatory to take advantage of relatively clear skies for an observing session... The astrophotograph [of M42/M43 shown here] was…taken with a Nikon D7500 camera with 400mm zoom lens piggy-backed on a 10" Meade LX200 telescope. My images were taken at ISO 6400, f/6.3 and with exposure times of 15-30 seconds. The sky glow from the crescent moon did not present any problem but by 8:30 pm a thin veil of clouds was presenting a challenge.” Well done Al!

RENEWING YOUR TCAA MEMBERSHIP

The TCAA works to promote in every way among its members and the public an interest in and knowledge of astronomy and its allied sciences, to advance amateur astronomy and observational techniques, to render assistance to other individuals or organizations working in the same or related fields, and to do everything necessary and proper to further such on a formal or informal basis. The TCAA is a Federally recognized non-profit entity organized exclusively for educational and scientific purposes within the meaning of Section 501(c)(3) of the Internal Revenue Service code. The TCAA currently supports family-friendly public observing sessions at SGNC, public outreach events such as the recent May 9, 2016 transit of Mercury and the August 21, 2017, total solar eclipse field trip, hosting of NCRAL meetings (2010 and 2016), September mini-conferences, and education courses for our membership and the public. The TCAA maintains three observatories, including payment of insurance, and publishes an award-winning club newsletter. We support Sugar Grove Nature Center through its membership program, maintain a loaner telescope program, and provide many other benefits as outlined in TCAA Guide #2 – Membership and Benefits. Your TCAA membership supports education and public outreach in Central Illinois and regions beyond. Membership dues and the generosity of its members are the club’s primary means of financial support. We receive no grants or public funds. We have unmet needs. By renewing your membership when it comes due, you can help to ensure our continuing efforts.

CRATER WARGENTIN AND MIRA ~ by Tim Stone ~

On the evening of March 7, with the promise of clear skies, I set up my telescope with my spectroscope to acquire some stellar spectra. I didn’t really have any targets in mind. I thought I’d just get in some acquisition practice, but unfortunately the clear night didn’t materialize. Instead, a high haze coupled with the waxing gibbous moon drowned out most of the stars and made spectrography a lost cause for the night. So, failing that objective, I decided to take a few images of the moon before I packed up and went home. In the early days of my astrophotography journey, my experience and equipment limited my targets and results. I was a rank beginner, with just my DSLR and my Meade 8” Schmidt/Newtonian the same one I now use for spectrography. The moon was easy enough to find, and so I spent my astrophotography nights attempting to make decent images of it. In September of 2009, I photographed the region around Schickard. I was intrigued by a crater near that landmark that seemed to have a rim, but no crater floor. I looked it up and found its name was Wargentin. My image from that night wasn’t very good, and I always thought I’d like to go back and get a better image of the crater.

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

This night, I was delighted to see the lunar libration had carried Wargentin into very favorable view. The night was windy, and seeing

was poor, but I took the video anyway. I was delighted to see the result reveal crater Wargentin and its surroundings very clearly. Wargentin, seen directly in the center of my image, is a lava bathtub. It seems to have filled to the brim with lava, and then stopped filling. The crater walls are still intact, but had they overflowed with magma, they would have quickly eroded. In some crazy twist of timing, the lava stopped flowing just before the crater collapsed, so we have this plateau-shaped crater, completely filled with cooled lava. Wargentin is named after Peter Wargentin, an eighteenth-century astronomer who observed the brightest recorded maximum of the famous variable star Mira. Coincidentally, I had recorded the spectrum of Mira at its recent maximum in November of 2019, almost exactly ten years after I first recorded crater Wargentin. The connection was as interesting as it was unexpected!

Mira is an M7 star in the process of blowing off its outer atmosphere to create what will undoubtedly become a lovely planetary nebula as it finally fades into a white dwarf. At its distance of 425 light years, it will be an amazing sight for some

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

astronomer a few million years from now. Meanwhile, as it brightens to maximum, its hydrogen envelope already emits light, which we see as the intense spikes at the blue end of the spectrum. Mira has the lowest temperature spectrum of all I’ve recorded so far. So, myself, Peter Wargentin, a crater on the moon, and Mira are all connected, albeit somewhat tenuously I must admit. I guess the real story here is that I’ve realized two objectives: Photographing crater Wargentin and engaging in spectrography. The rest is icing on the cake.

PUBLIC VIEWING SESSIONS FOR 2020

April 25: Mars and the Events of 2020 (CANCELED DUE TO PANDEMIC) 8:15-10:15 PM

Mars makes its closest approach to Earth every 780 days (1.9 years). The next closest approach will occur on October 13th, 2020, when it appears opposite the sun in the sky. Prepare now to observe Mars as it moves rapidly eastward among the stars of the zodiac, brightening all the while, and then suddenly executing an impressive 13-degree-long retrograde zigzag!

May 23: Galaxies of the Spring Sky (SPEAKER NEEDED) 8:45-10:45 PM

In the spring, our line of sight on the sky looks straight out of our galaxy into the vast space beyond, showcasing thousands of bright galaxies and millions of dim ones. We will tour this neighborhood of the universe, highlighting some of the most beautiful galaxies in the heavens.

June 20: Navigating with Stars (Sunil Chebolu) 9:00-11:00 PM

For centuries, navigators have relied on stars to identify directions, compute latitude, and even read local time. We will explore these ideas and also examine the problem of measuring one’s longitude at sea – a fascinating problem that defeated some of the best minds in the world for many years.

July 18: Jupiter & Saturn (SPEAKER NEEDED) 9:00-11:00 PM

Jupiter and Saturn offer stark contrasts when compared to the inner planets. We will review how and why they formed in their current locations and their impact on the formation of the rest of the solar system. We will learn how the two greatest planets are similar yet different.

August 22: Touring the Milky Way (Mark Cabaj) 8:15-10:15 PM

The Milky Way is one of the countless stellar islands floating in a cosmic foam of dark matter, dark energy, and matter. Humanity is trying to find out what our galaxy looks like inside and out using ingenious observing methods and increasingly more sensitive equipment. Take a tour of our “cosmic home” to see what we know so far.

September 19: The ISS: Past, Present, and Future (Sandullah Epsicokhan) 7:30-9:30 PM

The International Space Station (ISS) is humankind’s largest artificial satellite. Given the right time and conditions, it can be easily seen orbiting overhead. We will look at how it was constructed, how it is used, what it is like living in space, and where it is headed in the future.

October 17: Missions to Mars (Lee Green) 7:00-9:00 PM

As we reach our closest approach to Mars for the year, the Red Planet shines brightly throughout the evening. Let’s review the many spacecraft missions we’ve sent there, what they are revealing, and how they are paving the way for a future manned mission to Mars.

DID YOU KNOW?

Are you looking for back issues of The Are you looking for information about Are you looking for the TCAA Guides to OBSERVER? Look no further than here: the history of the TCAA? Find out more amateur astronomy? Visit this page: http://tcaa.us/Observer.aspx here: http://tcaa.us/History.aspx http://tcaa.us/TCAAGuides.aspx

Vol. 45, No. 4 The OBSERVER of the Twin City Amateur Astronomers April 2020

TCAA TREASURER’S REPORT AS OF MARCH 29, 2020

Checking Account Information

Memo Category Amount BALANCE 02/27/2020 1,002.01 Filing Fee Annual Report -10.00 Roy Lawry Dues Received 25.13 Electrical Service Waynesville Observatory (64.37) BALANCE 03/29/2020 952.77

Checking Account Balance – March 29, 2020 $952.77 Savings Account Balance – March 29, 2020 $2,017.98 - Includes $0.02 cents interest as of this date

Total TCAA Funds – March 29, 2020 $2,970.75

All transactions are reconciled with the bank statements as of this date.

Respectfully submitted, Dave Osenga, Treasurer

TCAA ACTIVE ON FACEBOOK

Did you know that the TCAA is very active on Facebook? We currently have nearly 900 followers, and very few of them are TCAA members! We encourage all users of social media to follow the TCAA to see what the club is doing and to learn about nightly events that only require the observer to step outdoors and view with the unaided eye. You can find us on Facebook by searching either TCAA or Twin City Amateur Astronomers. If you haven’t followed TCAA’s Face-book page, you have missed out on a lot of opportunities to view the sky with the unaided eye from town and country. Here we see Venus Passing Through the Pleiades and Viewing Venus During the Daytime. Subscribe now so you don’t miss more.