Prime Focus

The newsletter of the Tri-Valley Stargazers December 1996.
Translated (roughly) from postscript into HTML for your browsing and downloading pleasure.
The Clementine Mission released news of possible water ice preserved in permanent shadows at the lunar south pole. This polar view was created from 1,500 Clementine images shot in 1994. Credits: Clementine, BMDO, NRL, LLNL.


Holiday potluck
Club news notes
What's Up in December
Winter 's deep-sky
Comet Comments
Member's questionnaire
Membership application

TVS presents

What: Holiday potluck and celebration
When: December 20: Conversation: 7:30 PM, Dinner: 8 pm
Who: You and your family
Where: Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.

Come celebrate the solstice with your astronomy club, on December 20, the third Friday of the month. TVS will provide delicious roast turkey and baked ham, cooked to perfection by club chefs Rich and Barbara Green. By popular request, this year's "assignments" have been changed! Please see the list below for your contribution to the potluck. The first letter of your last name determines the dish you should bring. Please prepare enough to feed eight to ten hungry astronomers.

A through G Dessert
H through R Vegetable or Salad
S through Z Rice or Potatoes or Dinner Rolls and Butter/Spread
The club will furnish all the necessary disposable dinnerware. Coffee, tea, and punch will be available; bring your own soft drinks.

After dinner we'll swap observing tips and pass along good ideas for stocking-stuffer gadgets.

Club News Notes

Changes in store for 1997

Elections were held at the last general meeting, and a somewhat new board will lead TVS for the coming year. Dave Anderson was re-elected to another term as president. (Thanks, Dave, for your willingness to do it all for another year.) Our new vice-president is board veteran Chuck Grant. Gene Nassar returns as club treasurer. Earl Mack will serve as secretary until a new volunteer can be found for the position.

Others elected or re-elected to board positions are: Alane Alchorn, Dennis Beckley, Rich Combs, Russ Kirk, Dave Rodrigues, Debbie Scherrer, Al Smith, Dave Sworin, and Jim Zumstein. Rich Green continues in his ex-oficio position as past-president.

These new and familiar faces can be seen monthly at a new time. The General Meeting night now moves to the third Friday of each month. Dates for 1997 are: January 17, February 21, March 21, April 18, May 16, June 20, July 18, August 15, September 19, October 17, November 21, December 19.

Dues are due
Welcome to winter, that wonderful time of year when everyone is asking for your money. Add TVS to the lis t, too. Annual membership expires on December 31, so please plan to bring your checkbook to the holiday potluck.

The membership/renewal application form on page 6 has been reformatted to include a hold-harmless statement and electronic options for those of us with Web and cyberspace connections. If you wish to be notified by e-mail when the newsletter becomes available on the Website each month, please put an "X" on the appropriate line on page 6. Likewise, mark the corresponding line if you do not wish to receive Prime Focus by mail any longer.

Discounted subscriptions to Astronomy , and Sky & Telescope . are available at $20 and $27 respectively. Please mark these lines if you want to be included in the club order. It will be submitted the Monday following February 's general meeting. Subscription fees should be added to your annual dues on a single check, payable to Tri-Valley Stargazers.

Patron membership is available after one year of general membership in good standing, subject to the approval of the board of directors. Patrons pay an additional $40 annually, over and above their general dues. They have access to the 17.5-inch telescope and the Sky Shack observatory. Patron membership is limited, with first priority given to active Patrons wishing to renew. For details, call vice-president Chuck Grant at (510) 449-1500 (yes, this really is his home number).

Feeling flush?
Just in case you are not spending your last dime on renewals and subscriptions, the board asks you to remember that TVS is a tax exempt 501 (c)(3) corporation. Any donation you wish to make is tax-deductible in the year given.

If your employer provides matching funds for charitable donations, the club benefits twice from your donation, no matter how modest it is. A line for TVS contributions has been provided on the revamped application form on the last page.

You, and your employer if applicable, will receive an acknowledgment of the donation, suitable for proving to the IRS that you are all-around good guys and deserve a tax break accordingly.

Two new members joined at the November general meeting: Curt Lauma nn and George Takahashi. The holiday potluck is a great time to meet new members and renew old acquaintances. Be sure to add Curt and George to your list of folks to greet. Help them get to know all of us.

TVS wants you
Your skills are needed to help the club with its 1997 goals and programs. Two specific committee opportunities are available immediately. Attendance at planning meetings is welcomed but not required for either position.

The board is looking for a Speakers and Programs committee chair. This individual will assist in selecting the program topics for general meetings, and in scheduling and confirming speakers on those topics. Coordination with the board can be accomplished by e-mail and phone, if it is a burden to attend planning meetings.

Even nearer to our hearts (and stomachs) is the Hostitality chair. He or she arranges for beverages and snacks at each general meeting. The club foots the bill for these edibles, but needs someone to fetch them.

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

Eyes on the Skies BBS Mike Rushford (510) 443-6146

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

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 Membership: 185

What's Up in December

by Dave Anderson


16 Mon TVS Planning Meeting 7:00 PM Round Table Pizza, 1540 First St., Livermore (in Orchard Supply/Safeway/Longs shopping center).
17 Tue First Quarter Moon 1:31 AM
Saturn 3° south of Moon.
Algol at minimum 8:02 PM
18 Wed Galileo's first flyby of Europa (69 2 km) 10:54 PM
20 Fri Tri-Valley Stargazers holiday potluck 7:30 PM PST. Unitari an Universalist Church in Livermore, 1893 N. Vasco Road, Livermore. (3/4 mile north of I-580).
21 Sat Winter Solstice 6:06 AM
22 Sun Aldebaran 0.9° south of Moon; occulted in central Canada.
24 Tue Full Moon 12:41 PM
Venus 6° north of Antares.
25 Wed Christmas.
27 Fri Johannes Kepler's 425th birthday.
31 Tue New Year's Eve.
Mars 3° north of Moon.


1 Wed New Year's Day.
Earth at perihelion (nearest to Sun: 0.98 3 AU = 147,0 95,000 km).
Last Quarter Moon 5:45 PM PST.
3 Fri Quadrantid meteor shower peaks around 3 AM
4 Sat Excellent weekend for observing: no Moon until after 2:30 AM
Algol at minimum 12:57 AM
6 Mon Algol at minimum 9:47 PM
7 Tue Venus 5° south of Moon. (Look shortly before sunrise at 7:23 AM)
8 Wed New Moon 8:26 PM
9 Thu Young Moon less than 21 hours old at sunset (5:07 PM).
10 Fri First day of Ramad\342n.
11 Sat Excellent weekend for observing: Moon sets at 8:37 PM
12 Sun Space Shuttle Atlantis (STS-81) launch scheduled 1:17 AM (Mir docking mission.)
Mercury 3° north of Venus.
13 Mon Saturn 2° south of Moon.
asteroid 211 Isolda 8' (mag 11.7) from Crab Nebula (M1). (See January Astronomy, p. 70.)
15 Wed First Quarter Moon 12:02 PM
17 Fri Tri-Valley Stargazers meeting 7:30 PM Unitarian Universalist Church in Livermore, 1893 N. Vasco Road, Livermore. (3/4 mile north of I-580).

Some Winter Deep-Sky Objects

NGC869 & 884 The Double Cluster in Perseus, great in binoculars or telescope.
M1 The Crab Nebula, the remnant of the supernova of 1054 A.D.
NGC7789 A faint but very rich open cluster in Cassiopeia.
M45 The Pleiades in Taurus. Best in binoculars.
M37 Best of Auriga's open clusters.
M42 & M43 The Orion Nebula, a magnificent object.
M35 & NGC2158 Beautiful open cluster in Gemini with a rich, more distant neighbor.
NGC2392 Eskimo Nebula, a pretty planetary in Gemini.
M46 & NGC2438 Rich open cluster in Puppis with a planetary nebula.
NGC2237 & 224 4 Bright but huge Rosette Nebula in Monoceros and associated cluster.

Comet Comments

By Don Machholtz


C/1995 O1 (Hale-Bopp)
Date(00UT) R.A.(2000) Dec. El. Sky Mag.
12-18 18h23.4 m +01° 57' 27° E 3.5
12-23 18h29.9 m +02° 53' 27° E 3.3
12-28 18h36.8 m +03° 55' 27° E 3.1
01-02 18h44.0 m +05° 05' 28° M 2.9
01-07 18h51.8 m +06° 23' 29° M 2.7

C/1996 Q1 (Tabur)
Date(00UT) R.A.(2000) Dec. El. Sky Mag.
12-18 16h06.7 m +16° 40' 47° M 11.2
12-23 16h09.5 m +15° 20' 48° M 11.5
12-28 16h11.9 m +14° 08' 50° M 11.8
01-02 16h13.8 m +13° 04' 53° M 12.0
01-07 16h15.4 m +12° 06' 56° M 12.2

Comet Hale-Bopp continues to brighten as it passes north of the Sun and into the morning sky as 1996 draws to a close. Northern hemisphere observers will have difficulty seeing it for a few weeks, while southern hemisphere observers won't see it until May 1997. While Comet Hale-Bopp has developed jets near the nucleus, and a tail a few degrees long. Comet Tabur began to fade rapidly in late October. This was unexpected and it is unusual behavior for a comet. It may now be fainter than the adjusted magnitude estimates listed in the ephemerides below.

Several comets should be easily visible to us in 1997. Comet Hale-Bopp will likely be the brightest, reaching perihelion in late March. Between January and June, Periodic Comet Wild 2 will reach magnitude ten in the northern evening sky. At nearly the same time Periodic Comet Wirtanen will be of similar brightness. Periodic Comet Encke is visible to the southern hemisphere in mid-summer. Toward the end of the year Periodic Comet Hartley 2 may reach binocular visibility in the evening sky, while Periodic Comet Tempel-Tuttle crosses through the north polar region at magnitude nine. In addition to these returning periodic comets, one never knows when and where new comets will be discovered.

Orbital Elements

Object Hale-Bopp Tabur
Peri. Date 1997 03 31.86770 1996 11 03.50419
Peri. Dist (AU) 0.9170703 AU 0.84001480 AU
Arg/Peri (2000): 130.40061 deg. 57.37495 deg.
Asc. Node (2000): 282.46983 deg. 31.41231 deg.
Incl (2000) 89.38442 deg. 73.36167 deg.
Eccen: 0.99674010 1.0
Orbital Period: ~4700 yrs. Long period

Member's Questionnaire

This is the eighth year that a questionnaire will be used to improve the quality of the club programs and activities. The details of your response will be kept confidential. Summary results will be published in the April Issue of Prime Focus. Please answer all questions that apply. Attach an extra sheet of paper if necessary.

How did you learn about the club?_________________
Why did you join?________________________________
Are we meeting your expectations ?____Yes_____No

How long have you been interested in astronomy? __________years.

How long have you been a member?
____<1 year ____1-3 years ____3-5 years ____over 5 years

How often do you attend the monthly meetings?
Almost always____ About half the time____ Occasionally____ Never____

How often do you go to The Dark Site?
Several times a month_____ Once a month_____ Every 2-3 months____ 1-3 times a year______ Never______

Rate the following activities for their importance to you (1=very important, 5=no interest)

_____Monthly meetings/speakers
_____Star parties at The Dark Site
_____Public star parties
_____Field trips to Yosemite, White Mtns, etc.
_____Using the 30" telescope at Fremont Peak
_____Telescope making
_____CCD imaging
_____Astrophotography (film)
_____Deep-sky observing (faint objects)
_____School programs/presentations
_____Computer programs, Internet, bulletin boards

What kind of instrument do you use most for observing?

What program topics would you like us to cover at the meetings?
Do you have a computer? ____Yes ____No
Type:_____Macintosh _____IBM or Clone
Does your computer have a modem?___Yes ___No
Have you ever logged on to the TVS Bulletin Board?____Yes ____No
Do you have access to the Internet?_____Yes _____No
e-mail? _____Yes _____No

Have you visited the TVS web page? _____Yes _____No

Do you use your computer for astronomy related purposes?_____Yes_____No
If so, what?_________________________________________

Have you ever borrowed books from the TVS library? ____Yes ____No
Books you would like us to have:___________________________ ____________________________________
Are you interested in helping with a school program? ____Yes ____No

How is the newsletter format?____________________
How is the newsletter content ?___________________
Are there any activities that you would like us to provide?

Can you suggest any improvements to the club? ____________________________________________________


Tri-Valley Stargazers Membership/Renewal Application
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