Prime Focus

Newsletter of the Tri-Valley Stargazers March 1997
Comet Hale-Bopp was an obvious unaided-eye object in the eastern sky at sunrise in late February. This shot was taken from a site west of Williston, NC. (NASA: T. Forrest, J. Wolfe, and M. Norris)


March general meeting
Club news notes
What's Up in March
Comet Comments
Hale-Bopp chart
Observing variables
Membership renewal

TVS presents

What: Comets, particularly Hale-Bopp
When: March 21, 1997
Conversation, 7:00 PM
Business meeting, 7:30 PM
Who: Don Machholz
Where: Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.

Don Machholz began his comet hunting on January 1, 1975. After some 1,700 hours of searching he found his first comet on September 12, 1978. His second find took an additional 1,742 hours. Now, with more than 6,100 hours spent in search of comets, Don has a total of nine that bear his name. He stands in second place among the world's living visual comet discoverers, and is first in both the northern and western hemispheres.

A resident of Colfax, Don shares his comet hunting hobby with fellow amateurs in Placer County. He currently observes at a rate of about 250 hours (150 nights) per year. Each summer he holds astronomy classes at the Placer Nature Center. He also writes astronomy articles for local newspapers and radio stations.

Since 1978, Don has produced a monthly column entitled "Comet Comments". Prime Focus is just one of the many astronomy newsletters that features "Comet Comments". Don has also authored two books on comets and one on the Messier Marathon. For information about his publications call 916 346-8963.

Club News Notes

Comets and Crashes

On Saturday, March 22, the Lawrence Hall of Science and the Astronomical Association of Northern California will jointly present a workshop on all aspects of cometary observation.

"Comets and Crashes" will include speakers like Scott Sanford of NASA's Project STARDUST; Bruce Fouke of UC Berkeley; Jose Olivarez of Chabot Observatory and Alan Gould from the Lawrence Hall of Science.

Website information on the workshop schedule and keynote speaker are available at: AANC information is also available by dialing (510) 642-5132; press 1, then press 7.

Registration is $20 prior to March 12, and $25 at the door. An optional lunch costs $6 additional. Weather permitting, comet viewing will be held on the LHS plaza in the early evening.

Well, if you tried to join the board at February's planning meeting, you probably noticed that Round Table Pizza was full of the Apocalypse Riders motorcycle club, and not TVS.

Through a little mixup, "our" meeting room was given to the bik e club. Our board met at Boston Market, and we apologize to anyone who could not find us. Congratulations to the stalwarts who recognized TVS cars and joined us anyway.

For the March 24 planning meeting, we should be back at Round Table, 154 0 First Street, Livermore.

Big banks, little banks
In the continuing saga of bank mergers and consolidations, Community First National Bank, the TVS depository, will become part of U.S. Bank.

New statements had not been prepared by the Prime Focus deadline.
The checking account now holds approximately $521 9, with subscriptions paid to Sky & Telescope ,
but not yet sent to Astronomy. The CD and money market accounts are essentially unchanged.

Meeting dates
General Meeting nights are now the third Friday of each month: March 21, April 18, May 16, June 20, July 18, August 15, September 19, October 17, November 21, and the holiday potluck on December 19.

A special Comet Hale-Bopp viewing evening will be held at the Church on March 28. Yes, this is Good Friday, however, the TVS activities will not interfere with any church events.

Telescopes are welcome, and binoculars are encouraged. You may arrive before dark in time to set up your scope using daylight. The club will provide warm beverages and refreshments, but no program is scheduled.

Sky Shack notes
Chuck Grant reports that he has mounted the pier extension on the club scope. It is now 12 inches higher, and the drive should be repaired and the scope rebalanced by the time you receive this newsletter. Patron members with questions about the scope improvements should call Chuck at (510) 449-1500.
Paging Starbucks!
A few members have asked whether the club provides an alterna tive to the small Styrofoam cups used for coffee and tea at general meetings. No, but we do have a solution for you java junkies who need just a little bit more.

Feel free to bring your own mug of any size. Since we do have kitchen privileges, you can wash it out before you take it home. If you want to leave a mug in our hospitality box, tell Linda Cody, and she will pack it away with our supplies until the next meeting.

TVS supporters honored
The board wishes to thank members Dave Scimeca, Marilyn Hallberg, and the Chris Kitting family for their special donations to the club. Their gifts will be used toward the purchase of audio visual equipment to enhance our general meeting and star party presentations.

Kudos also go to the ever-dedicated Rich Green. A past president, Rich has taken up the mantle of school star party coordinator. If you would like to participate in bringing astronomy to the schools, contact Rich at 510 449-2190.

Light pollution update

In last month's Prime Focus, club member Robert Hoyle informed us about the sky glow problems seen from Fremont Peak. A Website for color photos of the Soledad Prison light pollution problem has been finalized as:

Robert notes that these photos are "powerfully persuasive".

Project ASTRO wants you

The Astronomical Society of the Pacific is seeking amateur and professional astronomers as well as advanced astronomy students to participate in Project ASTRO. This innovative program matches astronomers with 4th-9th grade teachers in Bay Area schools and community centers.

Project ASTRO astronomers form an ongoing partnership with a teacher. Astronomers agree to make at least four visits to their partner school or community center during daytime hours, working with the same teacher and students over time.

Astronomers with an interest in education and some experience working with children or teens, or in presenting astronomy to the public, are encouraged to apply. Applicants are required to attend a summer training workshop, where they will be paired with a teacher. Astronomers should also have time to plan lessens with their teachers between the school-time visits. ASP can provide verification letters for the astronomers' employers upon request.

Project ASTRO provides training that helps astronomers become effective resources for their teachers. Many hands-on activities are detailed in the workbook. During the school year, visiting astronomers can help with activities,

assist the teachers in astronomy lessen planning, organize evening observing sessions, create a school astronomy club, or otherwise enhance the school's science teaching endeavors.

The 1997 -98 training workshop is set for Friday, August 8 and Saturday, August 9 at the Lawrence Hall of Science in Berkeley. Participating astronomers are required to attend the workshop. Classroom visits will begin with the fall 1997 school year.

Preferred placement deadline is April 11, 1997, although applications will be accepted after that date. To request an application, call 415 /337-9210 ; or e-mail For specific information contact Nicole Taddune, Project ASTRO Bay Area coordinator, at ASP (415) 337-1100. Project ASTRO is funded by the National Science Foundation and NASA.

New Project ASTRO sites added

ASP has selected three new sites for the national expansion of Project ASTRO. They are: The Space Center in Alamagordo, NM; the astronomy department at Wesleyan University in Middletown, CT; and the department of astronomy for the University of Washington in Seattle, WA. These sites join the Adler Planetarium, Chicago, the National Optical Astronomy Observatories, Tucson, AZ, and the ASP in offering local programs.

Hale-Bopp Observing Chart

Comet Hale-Bopp Observing Chart TVS observatory director Chuck Grant generated this sky map of Comet Hale-Bopp's progress through the spring sky.

The two lines with double arrows indicate the periods when the comet should be best for visual astronomy. By the time you receive this newsletter, it should be approximately m0.5.

On March 28, the club will sponsor a public observing session at the Unitarian Universalist Church in Livermore. Members are invited to bring friends and family. On that date the comet is expected to be very bright in the western sky.

For more info try:

President Dave Anderson (510) 661-4249
Secretary Earl Mack (510 ) 828-1414
Vice President Chuck Grant (510) 449-1500
Treasurer Gene Nassar (510) 462-7843
Observatory Director Chuck Grant (510) 449-1500
Librarian Chris Cody (707) 747-6550
Eyes on the Skies BBS Mike Rushford
Web Site
Editor Alane Alchorn (510) 455-9464 (510) 455-9466 fax
Meeting Location Unitarian Universalist Church in Livermore 1893 N. Vasco Rd. 3/4 mile north of I-580
Membership: 185

Alane Alchorn
Dennis Beckley
Rich Combs
Rich Green
Russ Kirk
Dave Rodrigues
Debbie Scherrer
Al Smith
Dave Sworin
Jim Zumstein

Tri-Valley Stargazers
P.O. Box 2467
Livermore, CA 94551

Comet Comments


C/1995 O1 (Hale-Bopp)
Date (00 UT) R.A. (2000) Dec El Sky Mag
03-03 21h34.1m +34° 57' 46° M -0.4
03-08 22h06.8m +38° 40' 46° M -0.6
03-13 22h45.8m +41° 58' 46° M -0.9
03-18 23h30.8m +44° 28' 46° M -1.0
03-23 00h20.2m +45° 46' 45° E -1.1
03-28 01h10.4m +45° 38' 44° E -1.2
04-02 01h57.5m +44° 11' 42° E -1.1
04-07 02h38.9m +41° 43' 41° E -1.0

46P/ Wirtanen
Date (00 UT) R.A. (2000) Dec El Sky Mag
03-03 01h40.9m +07° 59' 44° E 10.4
03-08 01h59.2m +10° 32' 44° E 10.4
03-13 02h18.3m +13° 04' 44° E 10.3
03-18 02h38.1m +15° 32' 45° E 10.3
03-23 02h58.6m +17° 55' 45° E 10.3
03-28 03h19.9m +20° 10' 46° E 10.4
04-02 03h41.9m +22° 16' 46° E 10.5
04-07 04h04.5m +24° 10' 47° E 10.6

81P/ Wild 2
Date (00 UT) R.A. (2000) Dec El Sky Mag
03-03 07h47.1m +21° 37' 132 ° E 10.2
03-08 07h49.0m +21° 49' 128 ° E 10.2
03-13 07h52.1m +21° 57' 123 ° E 10.1
03-18 07h56.3m +22° 00' 119 ° E 10.1
03-23 08h01.7m +21° 59' 115 ° E 10.1
03-28 08h08.2m +21° 54' 112 ° E 10.1
04-02 08h15.6m +21° 43' 109 ° E 10.1
04-07 08h23.9m +21° 28' 106 ° E 10.1

by Don Machholtz

This year's first three comet discoveries have taken place. Comet C/1997 A1 (NEAT) was found by automated equipment in Hawaii on Jan. 10, it will remain faint. Periodic Comet P/1997 B1 (Kobayashi ) was found on Jan. 30. It was at first believed to be an asteroid, but has been showing cometary features. It orbits the sun every 26 years and always stays fainter than magnitude 16. Finally, Comet C/1997 C1 (Gehrels) was found by Tom Gehrels visually with the Spacewatch 36" telescope on Kitt Peak on Feb. 1. The comet was at magnitude 17 when found, but may reach magnitude 10 early next year.

Comet Hale-Bopp is putting on a fine show in the morning sky. Look for numerous jets near the center of the coma and a tail several degrees long. Joining the comet in the sky is a total solar eclipse on March 9 (from Siberia) and a partial lunar eclipse on March 23 (over most of the USA). Throughout the month of March, the comet's visibility in the evening western sky improves, while in the morning eastern sky the comet gets more difficult to see. As we reach perihelion (April 1) Comet Hale-Bopp will be a bright spectacular comet in the western sky as darkness falls each evening. Get out to see it, and show your friends, you are not likely to see a comet this large for a long, long time.

Orbital Elements
Object : Hale-Bopp P/Wirtanen P/Wild 2
Peri. Date: 1997 04 01.13453 1997 03 14.14299 1997 05 06.62789
Peri. Dist (AU): 0.9141030 AU 1.0637469 AU 1.5826156 AU
Arg/Peri (2000): 130.59083 deg. 356.34322 deg. 041.77000 deg.
Asc. Node (2000): 282.47069 deg. 082.20387 deg. 136.15458 deg.
Incl (2000): 089.42936 deg. 011.72255 deg. 003.24276 deg.
Eccen: 0.9950969 0.6567490 0.5402220
Orbital Period: ~4700 years 5.46 years 6.39 years
Ref: MPC 28052 MPC 27080 MPC 28272
Epoch: 1997 03 13 1997 03 13 1997 04 22
Absol. Mag/"n": -1.5/4.0 9.0/6.0 7.0/6.0

How Is Variable Star Observing Different From Deep Sky Observing?

by Dave Sworin

Variable stars are usually much more difficult to find than deep sky objects because most stars look alike. You must know the exact location of the variable with respect to the stars around it. This requires charts which show more stars on them and a very careful and exacting star hop.

It is not uncommon for beginning variable star observers not find a single variable on their first night. For example, some Mira variable stars vary between magnitude 9 and 14 over a period of a year. If the star is at magnitude 12 when you try to make your observations, Uranometria is not nearly detailed enough to find the variable.

The first time you see a deep sky object is frequently the greatest thrill. Deep sky observers are always seeking out new objects and new thrills. Of course deep sky observers have their favorites, but you can only look at M82 so long for so many times before you want to see something else. In contrast, the first time you see a variable star, it is the least impressive and interesting observation you will ever make of that star. It looks just like a star, like most any other star.

Now when you go back a week later and find it has changed in brightness, now it starts to get more interesting. The more you observe it, the more changes you see. The more familar you are with the variable, the more differences from other variables you notice and the more irregularities you discover. A variable star is more interesting the more you observe it.

Deep sky observing is an experience in space. The vast reaches of our universe unfold before your eye and stretch your imagination to comprehend the size and relationship of where we are in the universe. The time element is hidden in the eons of time it takes for changes in deep sky objects to unfold. With variable stars, time not space is the dimension of interest. This is difficult to feel until you are into variable star observing for more than a year, for like the seasons of the constellations, variable stars have their own rhythm.

Vision is the key discriminator of space, but time is in your breathing and the beating of your heart. Variable star observers use their eyes to find the stars and make the magnitude estimates surely, but the joy is in the experience of changes with time, in the dynamics of our universe.

Aperture fever is common among all amateurs, but it is particularly strong in deep sky observers because what you can see increases dramatically with aperture. In variable star observing however, you do not need a big scope to see time, it is right there on your wrist watch, in plain sight.

There are many unaided-eye variables and many more binocular variables. A small telescope puts thousands of variables within your reach. Telescope aperture is not as important.

Light pollution is very detrimental to deep sky observing. The difference is so amazing that many amateurs only observe at dark sky sites, away from their home. In contrast, variable stars are not bothered as much by light pollution. For amateur telescopes, a variable star is just a point of light, high magnification darkens the sky background allowing you to see the variable. Many, if not most, variable star observers observe from their back yards.

You can not do variable star observing very well by yourself. You need an organization. You need people around the globe. Deep sky observatories can congregate in one location, like Chile or Hawaii, where the best observing conditions are located. Not so with variable star observing.

Time waits for no man, you've heard it said, and neither do the clouds nor the Sun. You will miss many observations important to following the behavior of your variable stars, but luckily, variable star organizations exist around the world and cooperate internationally in a wonderful way. When you are sleeping, someone is Hungary is making an observation of SS Cygni as it starts to go into outburst, jumping from magnitude 12 to magnitude 8 in one day.

TVS Membership Application

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