JANUARY 2018

March 2020

March Meeting Details March Presentation

DATE: Tuesday, March 10th

MEETING TIME: 7:00 PM

PLACE: La Posada Recreation Center

MEETING SCHEDULE:

7:00 Meeting Intro and Welcome

7:10 Organizational Announcements

7:30 Featured Presentation

~8:15 Club Activities/Business

~8:30 Door Prizes Drawing?

~8:45 Outside Activities/Snack at

Denny’s

Join us after the meeting at the local Denny’s restaurant for a snack, dessert, or whatever so we can get to know each other better and talk more astronomy .

Next Member Star Parties

DATE: Thursday, March 26th

TIME: 6:00 PM Setup

PLACE: Canoa Preserve Park

DATE: Thursday, April 23rd

TIME: 6:45 PM Setup

PLACE: Canoa Preserve Park

DATE: Thursday, May 21st

TIME: 7:00 PM Setup

PLACE: Canoa Preserve Park

To get directions and up-to-date infor-mation on the status of a star party in case a weather issue develops.

If you have a telescope that you don ’t

know how to use, or are looking to buy

a telescope and want to compare differ-

ent telescopes, join us at a star party

and we can give you some help.

WHO: Dr. Knut Olsen

TITLE: A Tale of Two Galaxies

ABSTRACT: Dr. Olsen will present a

personal story of how a chance observing run

kicked off more than a decade of exploration of

and discovery in the Magellanic Clouds, two of

our most prominent neighbor galaxies. The

Magellanic Clouds have been key to

establishing the extragalactic distance scale,

played a seminal role in the discovery of Dark

Energy, and are causing us to adjust our view of

the Milky Way.

ABOUT THE SPEAKER: Dr. Knut Olsen is a

staff astronomer at the National Science

Foundation’s Optical-Infrared Astronomy

Research Laboratory, based in Tucson. Born

in Norway, he moved to the U.S. at a young age

and quickly developed a fascination for

astronomy. He worked on the Magellanic

Clouds as part of his Ph.D. thesis, and

continued his exploration of them while living

and working in La Serena, Chile, where the

Clouds are naked eye objects. He moved to

Tucson in 2007.

SONORAN STARRY NIGHTS

March 2020 2 Volume XII Issue 7

UPCOMING EVENTS

NEXT MEETING

DATE: April 14th

TIME: 7:00 P.M.

SPEAKER: TBD

PRESIDENT’S NOTES

Greetings everyone,

Another club star party was wiped out in February along with two public star parties. One school star party did make it and one solar party made it half way.

We had two public star parties scheduled for last month. One was at Historic Canoa Ranch, the second was at Tumacocori. Both were wiped out by clouds or rain. We participated in two school star parties. The first was at Calabasas School in Rio Rico in coordination with their STEAM event. We had an excellent night except that it was a little windy. The following day we participated in the Sahuarita Middle School STEMtacular event. This event brings into the Sahuarita Middle School gym students from all Sahuarita middle school grades to an event which hopes to get them enthusiastic about science, technology, engineering, and math. A number of companies had displays showing different types of information in those areas. Our speaker from last month (Cassandra Lejoly) was there representing the Lunar Planetary Lab with a meteorite display. We participated in the solar party outside the gym. The sky was fine in the morning but shortly after noon the clouds rolled in and wiped out the rest of the event. February was not a great month for observing.

John Dwyer, President SAS

PUBLIC STAR PARTIES

DATE: March 20th

TIME: 6:00 PM Setup PLACE: Historic Canoa Ranch 6:30 – 7:30 PM Whipple Observatory Presentation/Lecture DATE: March 24

th

TIME: 6:30 PM Setup PLACE: Tumacocori National Historical Park DATE: April 24

th

TIME: 6:45 PM Setup PLACE: Historic Canoa Ranch DATE: May 22

nd

TIME: 7:30 PM Setup PLACE: Historic Canoa Ranch

CLUB EQUIPMENT FOR LOAN OUT

TELESCOPES:

2 - 8” Celestron Schmidt Cassegrain telescopes

1 – 4” Refractor telescope

1 – 1” Refractor telescope

Note: Instruction may be required for some telescopes. Contact one of the club officers for information and availability.

CLUB BOOK/CD/DVD LOAN LIBRARY

BOOKS:

The following books are available for check out:

1. Guide to the Stars (16”) by David H. Levy

2. The Next Step: Finding and Viewing Messier’s Objects by Ken Graun

3. Touring the Universe: A Practical Guide to Exploring the Cosmos through 2017 by Ken Graun (2 copies)

4. What’s Out Tonight? Celestial Almanac & Astronomy Field Guide 2000 to 2050 by Ken Graun (2 copies)

5. Sky Atlas 2000.0 Companion by Robert A. Strong (donated by Paul Anderson)

Please see the club treasurer or secretary for availability. Our thanks to Ken Graun for his generous donations. CDs/DVDs:

We have “Understanding the Universe: An Introduction to Astronomy”. This is a 16 DVD set of 96 lectures (30 min per lecture) by Dr Alex Filippenko of UC Berkeley and CalTech. This is a nontechnical introductory college-level course on astronomy. More information about this course can be found at http://www.teach12.com/ttcx/coursedesclong2.aspx?cid=1810. Please see the club treasurer at the next meeting for availability.

SONORAN STARRY NIGHTS

March 2020 3 Volume XII Issue 7

THE MARCH SKY

Venus is still the primary evening sky object shining brilliantly at mag -4+ all month high in the western sky. It will reach greatest eastern elongation (46°) from the Sun on the 24th and will be about 60% illuminated. Jupiter is visible in the morning sky, rising about 3 hours before the Sun. Saturn, now also in the morning sky, rises about a half hour after Jupiter. Mars, in the eastern morning sky as well, is appearing to move east in the sky as the Earth is slowly catching up to it. Mars will be moving back towards Jupiter and Saturn and will catch up with Jupiter on the 20th and Saturn on the 31st and will be within 1° of each on those dates. Mercury returns to the morning sky for this month and will reach greatest western elongation (28°) from the Sun on the 24th, but will be better positioned for viewing in the Southern Hemisphere. Uranus, in Aries, is in the southwest evening sky at sunset, but will be becoming more difficult to view this month. It will be very near Venus early in the month. Neptune will be lost in the Sun this month.

There is still only one comet that is currently visible. Comet C/2017 T2 (PanSTARRS) is around 9th magnitude. It will be in Cassiopeia as the month goes on. It is not an easy target as it is rather faint and small. It is predicted to reach 8th magnitude next summer. It will be well positioned for Northern Hemisphere observers up to that time.

Still keep a look out in the evening for the Zodiacal Light this month in the two weeks after the full Moon.

MARCH MOON/SUN TIMES

WANT TO VIEW SATELLITES? WANT CURRENT COMET INFORMATION?

To find out information on when you can view satellites,

such as the International Space Station (ISS), or satellite

related events, such as Iridium Flares, go to www.heavens

-above.com. Under “Configuration”, use “select from

map” to enter your specific location (precision can make a

difference for Iridium Flares), and choose what satellite’s

information you want to view. Also, information on comets,

planets, and other objects are available.

Go to “The Weekly Information about Bright Comets” site

at http://www.aerith.net/comet/weekly/current.html.

Comets are listed in brightest to least bright order.

Remember, to see a comet without any optical aid, it must

be approximately 4th magnitude or brighter. With binocu-

lars, the comet would most likely need to be at least 8th

magnitude. Comets below 11th magnitude might be

difficult to pick up with other than a large aperture

telescope. Visibility can also depend on how diffuse the

DATE M-Rise M-Set M-Phase Sun-set Star Party

Sun 03/01 10:51 ----- 18:22

Mon 03/02 11:31 0:50 1st Qtr 18:23

Tue 03/03 12:15 1:48 18:23

Wed 03/04 13:07 2:47 18:24

Thu 03/05 14:06 3:45 18:25

Fri 03/06 15:12 4:39 18:26

Sat 03/07 16:21 5:29 18:26

Sun 03/08 17:33 6:15 18:27

Mon 03/09 18:43 6:56 Full 18:28

Tue 03/10 19:54 7:36 18:29 SAS Meeting

Wed 03/11 21:03 8:13 18:29

Thu 03/12 22:12 8:51 18:30

Fri 03/13 23:20 9:31 18:31

Sat 03/14 ----- 10:12 18:31

Sun 03/15 0:25 10:58 18:32

Mon 03/16 1:28 11:48 3rd Qtr 18:33

Tue 03/17 2:25 12:40 18:33

Wed 03/18 3:18 13:36 18:34

Thu 03/19 4:03 14:32 18:35 Dsrt Shdw MS

Fri 03/20 4:44 15:29 18:36 Canoa Rch

Sat 03/21 5:20 16:24 18:36

Sun 03/22 5:52 17:19 18:37

Mon 03/23 6:22 18:12 18:38

Tue 03/24 6:51 19:05 New 18:38 Tumacacori SP

Wed 03/25 7:19 19:59 18:39

Thu 03/26 7:48 20:52 18:40 SAS SP

Fri 03/27 8:18 21:48 18:40

Sat 03/28 8:51 22:43 18:41

Sun 03/29 9:28 23:41 18:42

Mon 03/30 10:10 ----- 18:42

Tue 03/31 10:58 0:38 18:43

(S)=Solar

SONORAN STARRY NIGHTS

March 2020 4 Volume XII Issue 7

THE STARGAZER’S CORNER: Dim Delights in Cancer

Cancer the Crab is a dim constellation, yet it contains one of the most beautiful and easy-to-spot star clusters in our sky: the Beehive Cluster. Cancer also possesses one of the most studied exoplanets: the superhot super-Earth, 55 Cancri e.

Find Cancer’s dim stars by looking in between the brighter neighboring constellations of Gemini and Leo. Don’t get frustrated if you can’t find it at first, since Cancer isn’t easily visible from moderately light polluted areas. Once you find Cancer, look for its most famous deep-sky object: the Beehive Cluster! It’s a large open cluster of young stars, three times larger than our Moon in the sky. The Beehive is visible to unaided eyes under good sky conditions as a faint cloudy patch, but is stunning when viewed through binoculars or a wide-field telescope. It was one of the earliest deep-sky objects noticed by ancient astronomers, and so the Beehive has many other names, including Praesepe, Nubilum, M44, the Ghost, and Jishi qi. Take a look at it on a clear night through binoculars. Do these stars look like a hive of buzzing bees? Or do you see something else? There’s no wrong answer, since this large star cluster has intrigued imaginative observers for thousands of years.

55 Cancri is a nearby binary star system, about 41 light years from us and faintly visible under excellent dark sky conditions. The larger star is orbited by at least five planets including 55 Cancri e, (a.k.a. Janssen, named after one of the first telescope makers). Janssen is a “super-earth,” a large rocky world 8 times the mass of our Earth, and orbits its star every 18 hours, giving it one of the shortest years of all known planets! Janssen was the first exoplanet to have its atmosphere successfully analyzed. Both the Hubble and recently-retired Spitzer space telescopes confirmed that the hot world is enveloped by an atmosphere of helium and hydrogen with traces of hydrogen cyanide: not a likely place to find life, especially since the surface is probably scorching hot rock. The NASA Exoplanet Catalog has more details about this and many other exoplanets at bit.ly/nasa55cancrie.

How do astronomers find planets around other star systems? The Night Sky Network’s “How We Find Planets” activity helps demonstrate both the transit and wobble methods of exoplanet detection: bit.ly/findplanets. Notably, 55 Cancri e was discovered via the wobble method in 2004, and then the transit method confirmed the planet’s orbital period in 2011!

Want to learn more about exoplanets? Get the latest NASA news about worlds beyond our solar system at nasa.gov.

SONORAN STARRY NIGHTS

March 2020 5 Volume XII Issue 7

OFFICE/POSITION NAME PHONE NO.

Chairman of the Board Open

President John Dwyer (520) 393-3680

Secretary Michael Moraghan (520) 399-3352

Treasurer John McGee (520) 207-6188

Star party Coordinator Duane Johnson (520) 303-6920

Newsletter Editor John Christensen (520) 869-8983

Webmaster Joe Castor (620) 584-4454

ALCOR* Burley Packwood (520) 396-3576

NSN** Representative Duane Johnson (520) 303-6920

Past President Emeritus Dan F. Case (520) 207-6833

*Astronomical League Coordinator

**Night Sky Network

S.A.S CLUB OFFICERS

SAS STATISTICS & FINANCES

Lifetime Members: 0 Bank Balance as of End of Jan: $2930.20

Individual & Family Members: 163 Deposits / (W/Ds): $225.00/($51.99)

Total Membership: 163 Bank Balance as of End of Jan: $3103.21

WHY JOIN SAS CLUB DUES

SAS WEB SITE

1. SAS Family Membership Fee is only $15.00 per year.

2. SAS monthly newsletter “The Sonoran Starry Nights.”

3. Top-quality astronomy lectures by local astronomers!

4. SAS Discount for Astronomy Magazine $34.00 for 1yr

or $60.00 for 2 yr renewed through our treasurer.

5. SAS Discount subscription rate for Sky & Telescope

Magazine $32.95 for 1-year self-renewed.

6. RASC Observer’s Handbook at a discount, $30.00.

7. SAS T-Shirts for sale for $10.00—M, L, XL.

8. Member of International Dark-sky Association (IDA)

and The Astronomical League.

9. SAS Discount for Astronomy 2020 Calendar $10.00

10. SAS monthly Member Star Parties.

11. SAS Telescope and astronomy book loan programs.

12. SAS outreach to astronomy education in schools.

13. SAS fellowship with other amateur astronomers!

Dues (family or individual) are $15 annually, payable each

year in the month you initially joined the club. You will

receive a reminder in the monthly newsletter e-mail of your

due date. You can either pay at the club meeting or mail it

to the club’s address (S.A.S., P.O. Box 1081, Green

Valley, AZ, 85622).

If you want to keep up-to-date with club activities, such as

star parties, etc., check out our website at:

sonoraastronomicalsociety.org

SONORAN STARRY NIGHTS

March 2020 6 Volume XII Issue 7

LOCAL ASTRO-IMAGING GROUP: Sonoran Desert Astro Imagers (SDAI) (Larry Phillips, Coordinator)

Are you interested in Astrophotography or are you currently involved in imaging the skies?

Please plan to join our monthly meeting of the Sonoran Desert Astro Imagers group. Our meetings

focus on improving our skills, helping each other, workshops, and field trips. Please send your Name

and E-mail address to my address below and we’ll include you in the emailing notices of monthly

meetings; “the when and where meeting notice.” Do you have any questions? If so, call me (Larry

Phillips) at (520) 777-8027 or email to llp41astro@cox.net.

Clear Skies! Larry Phillips

SAS IS A MEMBER OF THE ASTRONOMICAL LEAGUE SAS IS A MEMBER OF IDA

OUR SPONSORS

S T A R I Z O N A

ADVENTURES IN ASTRONOMY AND NATURE

5757 N. Oracle Rd www.starizona.com

Tucson, AZ 85704 (520) 292-5010

Stellar-Vision Astronomy & Science

Since 1986

New Address:

3721 E 37TH ST

TUCSON AZ 85713

(520) 571-0877

http://www.stellarvisiontucson.com

Since SAS is a member of the Astronomical League, any SAS member may join the Astronomical League for a nominal fee of $7.50. What are the advantages to you of joining the AL?

1. You can receive various observing awards by joining an “observing club” and observing the required number of objects. There are all levels of clubs from beginner to advanced, viewing constellations to deep-sky objects and using either your naked eyes, binoculars, or a telescope. Contact our ALCOR rep Burley Packwood for details.

2. You can get a 10% discount on books purchased through the AL Book Service.

3. You will receive the AL’s quarterly “Reflector” magazine which keeps you up to date on all the AL activities.

More info at www.astroleague.org

SAS is proud to be a member of the International Dark-Sky Association, supporting the reduction in light pollution around the U.S. and the world. More info at www.darksky.org

SAS NON-PROFIT STATUS

The Sonora Astronomical Society is a 501 (c) (3) nonprofit charitable organization! SAS has a CERTIFICATE OF GOOD STANDING from the State of Arizona Corporation Commission for 2009-2011!

MAGAZINE SUBSCRIPTIONS

To order or renew your Sky and Telescope Magazine at the Club Rate, you can go directly to www.skyandtelescope.com/clubspecial To order or renew Astronomy Magazine, see the

Treasurer.

SONORAN STARRY NIGHTS

March 2020 7 Volume XII Issue 7

EQUIPMENT FOR SALE (CONT)

3. Orion XT8 Plus Dob.

If you are interested in this scope, contact Robert

Shropshire at rshropshire1@aol.com for more information.

4. Celestron CPC 1100 Computerized

Telescope.

includes:

Starbright XLT optical coating

GPS with SkyAlign for quick & easy alignment

9x50 finder scope & Telrad finder

microfocuser

2” star diagonal with Virtual View swivel adapter

40 mm x 1.25” Celestron Plossl eyepiece

13 mm x 1.25” TeleVue, Nagler IV eyepiece

17 mm x 2” TeleVue, Nagler IV eyepiece

2” 2x Barlow magnifier

hand control with 2 line LCD screen

sturdy tripod with 2” diameter steel legs

compatible with StarSense technology & WiFi

ergonomic carrying handles

12 V cable & 120 V adapter

metal carrying case for accessories, manual, original

packaging

In excellent condition was $4400 new, asking $2850 obo

Please contact Murray Croot, at (520) 372-2383

or mcroot@gmail.com for photos.

EQUIPMENT FOR SALE

One of our club members (John Verderame) is offering a service to sell equipment. Here is John's info:

"If you have astronomy equipment sitting around collecting dust, or just want to get some cash for your equipment, please contact me! I some-times buy equipment outright for cash, or if you would like me to help you sell something larger or more expensive, I can do that for a small com-mission. This is the only way I get new or better equipment, and I did it for the Prescott Astrono-my Club too. I sell mainly on Cloudy Nights and eBay, but also sometimes CraigsList, and have all positive feedback (I go by my actual name on Cloudy Nights if you wish to check me out).

Please call (I don't do texting) 307-250-2728 or email me at: astroitalian@gmail.com.

Thanks! John Verderame

1. Celestron 11” Nexstar GPS (Go-To)Telescope.

Includes:

* Alt-Azimuth Mount

* 1 Eyepiece

* Landing Pad

* Feather Touch Focuser

* Vibration Pads

* Asking $1400

Contact Lyle Kolze at (608) 346-5957 or

lkolze@yahoo.com

2. Orion Skyquest xt10i For Sale.

includes:

The telescope is an Orion Skyquest xt10i which has a

computer that can locate 14000 items in the sky. It is as-

sembled and the mirror and scope have been checked. It

comes with a carrying case. It’s never been used. I decid-

ed that another telescope would be better suited for me.

Original price was $900. Asking $850 which includes the

carrying case, a $120 value. I live in Green Valley .

Contact Ed Matte at EdMatte@msn.com

SONORAN STARRY NIGHTS

March 2020 8 Volume XII Issue 7

The Speaker: Cassandra Lejoly, Ph.D. Candidate at the UA Lunar & Planetary Laboratory

Subject: Researching Comets: The Forgotten Dust Particles

The speaker at the February 11th meeting was Cassandra Lejoly, Ph.D. Candidate at the U of A’s Lunar & Planetary Laboratory. Her topic was “Researching Comets: The Forgotten Dust Particles”.

Cassandra began by summarizing how planetary systems form from a condensing cloud of gas and dust that becomes denser and denser. She then discussed why comets are important, how she got her data, how she reduced it, some analysis and results, and, finally, why should we care.

During the formation of the solar system, the orbits of Neptune and Uranus crossed, disrupting the orbits of many planetesimals, creating the asteroid belt between Mars and Jupiter and the Kuiper belt further out. The Kuiper belt is the primary source of periodic comets. Even further out is the Oort cloud, which can also be the source of periodic comets, however, the periods are thousands of years long.

Comets are fluffy aggregates, as dense as the dust bunnies that form under our beds. They can clump together to form conglomerates and eventually planetesimals. It is not clearly understood how conglomerates form.

While the existence of comets has been known since ancient times, Edmund Halley was the first to predict the return of one, now known as Comet 1P/Halley. Unfortunately, he did not live to see the predicted return. On its next return, in 2061, it will be close and very bright.

Comet anatomy: nucleus, coma, a gas ion tail, and a dust tail. The ion tail is opposite the direction of the sun, blown by the solar wind, while the dust tail is opposite the comet's direction. Comet imagery show nuclei differ widely in shape but tend to be about 10 miles wide with a dark, porous surface. The coma is a cloud of dust and gas, usually spherical and can be a large as the diameter of Jupiter.

Cassandra just finished a major observing campaign occasioned by the apparition of three Jupiter family comets, i.e., comets with orbits dominated by Jupiter. The comets were 45P/HMP, 41P/TGK, and 46P/Wirtanen. Observations were made with radar, near-infrared and visible light. During spring 2017 and fall 2018 she spent over 100 nights of telescope time.

She observed with the 61-inch Kuiper telescope on Mt. Bigelow, next to Mt. Lemon. It has non-sidereal tracking, useful for following comets. Also, the Bok 90-inch telescope on Kitt Peak. One problem was both telescopes used the same filter, so she had to plan on which telescope to use the filter. Other telescopes she used were the Vatican 1.8-meter telescope on Mt. Graham, the Large Binocular Telescope, also on Mt. Graham, and the Arecibo telescope in Puerto Rico. With the latter, she used its radar capability to determine the shape of the comets. All the scopes had peculiarities. For example, what turned out to be a "ghost" in the LBT optical images caused Cassandra to lose two months of work.

She reduced collected data to produce light curves and brightness overtime looking for periodicity. She also studied jet features and will soon publish a paper about them. They appear as slightly brighter features within the coma. Studying them can help to determine the rotation of the comet, outflow velocities and differences in jets formed by various gases, such as OH and CN.

The gases lift dust off the surface a comet. Contrary to most comet researchers, Cassandra studies that dust. To determine if the dust exhibits a steady-state spherical expansion, Cassandra measured the brightness of the coma at two distances away from the nucleus. She found differences in the radial profiles of the three Jupiter family comets. In addition, there has been disagreement among investigators about the periods of the comets, especially 41P/Wirtanen. Radar data and light curves show different periods while the jet feature studies showed no periodicity. Cassandra wonders if these differences can be explained by the observations having been made at various times, such as pre-perihelion and post-perihelion. The periodicity of comets can change over time due to non-gravitational forces.

More research is required. These studies are important to understand the nature of comets which in turn will help us learn more about how the solar system formed.

JCM

SUMMARY OF THE JANUARY 14TH PRESENTATION