Prime Focus

Tri-Valley Stargazers March 1998

Supernova 1987A shows a brightening knot in its aparent ring. This collision site marks the meeting of a blast wave and the inner part of the circumstellar ring. The collision heats the gases, causing brightening. As new ejecta hits the ring, SN 1987A is expected to become a powerful emitter in the X-ray and radio frequencies. (Credit: Hubble Space Telescope, STScI-PRC98-08, 2/10/98)

IN THIS ISSUE TVS presents What: Through the looking glass: all about eyepieces
Where: Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.
When: March 13, 1998 Conversation, 7:00 PM Program begins, 7:30 PM
Who: You and your family, Rich Combs

Everything you ever wanted to know about eyepieces, both practical and theoretical, will be explained by Rich Combs at the March general meeting. Experienced observers are invited to ask Rich specific questions about the best eyepieces for observing at the Sky Shack and elsewhere. Beginners will find that the evening is an excellent and friendly introduction to the complexities of telescope optics. Club loaner scopes will be available, if you wish to test drive an eyepiece with Rich's help.

1998 ATM workshop Flush with the success of his most recent group, Rich is willing to teach another amateur telescope makers' workshop. Jim and Heather Nunes have again graciously volunteered the use of their facility. Amat eur scope makers should plan to meet twice a week for three to four months to complete a Dobsonian under Rich's direction. He estimates that the total cost of an ATM scope is $350-400. For class information, you may call Rich at 510 846-1906; or e-mail him at

TVS ponders Sky Shack uses and investments

More than 50 members shared pizza and astronomy stories at the February general meeting; and about 30 even stayed to debate the highest and best use of our leased dark sky site and observatory. As you may already know, our 17.5-inch club telescope currently suffers from excessive vibration when in use.

This problem can be solved in a variety of specific ways, with particular implications for members who use the scope for different purposes. Solutions have prompted broader discussions about the entire site, and its potential for greater use by more members of the club. Please read carefully this month's articles regarding the dark sky site and the telescope. An opinion poll/ballot is printed below. Your candor and imagination are equally valuable to the club discussions on this subject.

Observatory director Chuck Grant has recapped the telescope's problems in the article that follows. On page 6, some of the broader concerns about the observing hill and its uses - both current and potential - are noted. The Sky Shack and its scope will be on the agendas at future general meetings and planning meetings. As always, you are actively encouraged to attend both. Members who cannot attend the meetings may participate by e-mail to:

President Dave Anderson
Editor Alane Alchorn

or any board member with whom you correspond.

Observatory director's thoughts on the telescope mount problem

by Chuck Grant

The primary problem with the existing mount is vibration. With its massive aluminum tube assembly and rather thin drive shafts, the telescope is not unlike a giant tuning fork. Repositioning the scope, focusing, or the slightest breeze sets it shaking to a very unsatisfactory degree. It is not a very heavy-dut y mount, and it never was completely satisfactory on that telescope. The problems were compounded when the aluminum tube was installed, mostly due to its additional weight. The old cardboard tube also may have actually absorbed some of the vibration, while the aluminum tube is quite springy. The aluminum tube is also longer, adding to the weight and vibration.

The current mount, a Meade DS-16, was the largest mount available at the time, without going into the several-thousand-dollar range. Now that the club is in a different financial state, perhaps spending a few thousand dollars on a suitable mount and producing a truly fine instrument is the way to go. One mount under consideration, made by Opticraft Machining, is about $3,500. This mount has 3.5-inch diameter solid steel shafts. The present DS-16 mount has 1-inch diameter solid steel shafts, so the newer design would clearly be a substantial improvement. The board wanted to know the sense of the membership on this issue, and on the observatory/dark site in general, so a discussion was held at the last general meeting. Thirty-two members were present during the discussion, but the board wants to hear from all the members on this subject, especially Patron Members, and others who use the telescope or the dark sky site regularly.

A variety of interesting ideas was suggested, and some of the constraints limiting them were discussed. The major topics are highlighted below.

What about a fork mount? Some very large and sturdy amateur-constructed fork mounts currently enjoy a high degree of popularity.

Constraints: A fork mount does not allow the telescope to "fold over" like the German equat orial mount we have. Thus, the telescope would have to be mounted lower in the observatory, reducing the amount of visible sky. A fork mount would also move the pivot of the tube closer to the base, causing the eyepiece end of the tube to swing in a wider circle (nearly twice as wide). The fork-mounted telescope probably would not even fit inside the existing observatory building. In addition, there is much to be said for simply buying something and getting it working quickly, rather than keeping the scope out of commission for a long time during an extended major construction project.

What about geting an easy-to-use scope, such as a 12-inch LX200?

Constraints: The LX200 is fork-mounted, so it would have to be mounted low in the observatory. This mount/scope combination is ideal for a small dome; and costs about $5,000. It is a significantly smaller scope, just 12 inches at this price point. At 17.5 inches, the club scope is likely to be bigger than any equatorially-mounted telescope owned by most members. The question of getting good optics is also an important one, as the refigured primary on the TVS 17.5-inch is very good.

What about a computerized altazimuth mount such as a Mel Bartel's mount or the Bradford Robotic Telescope?

Constraints: The club telescope is used by many different people. There is a lot to be said for the simplicity of just turning it on and starting to observe. These complex designs require lots of parts that are subject to breakage or failure. Keep in mind, we do not have electrical service at the observatory, and therefore we don 't have the electricity to run very much computer equipment from there. Alt-az mounts suffer from the same low-position, limited visibility, and wide-swing faults as fork mounts, making them equally unsuitable for our building.

What about reinstalling a cardboard tube, or substituting a truss or a composite tube?

Constraints: The mount never really was strong enough, even with the cardboard tube; but we just lived with it. A cardboard (Sono) tube also flexes, causing its own set of problems. Keeping the focuser perpendicular while using a big Nagler on a 4-inch extension is a real problem for a cardboard tube. A truss tube would be a major engineering project. It would require a true Serrier truss, not the simplified one-section assembly found on large Dobs. A composite tube is an interesting idea, however we probably would still need a new mount.

What about a new building? A dome perhaps?

Constraints: We are building a dome! for a 16-inch scope (I think we are two years into the project and we haven't broken ground yet). Changing the existing building would be a major project and would take the scope out of commision for a long time. Probably even more difficult, is the question of what kind of new building to erect. Answering this first requires defining the types of observing, equipment, and astronomers for the future, and desiging a building to meet these needs. The 17.5-inch on a German equatorial mount housed in our sliding roof observatory has served the club very well for a long time -- for visual astronomy, astrophotography, and as a focus of star parties. The advantages of going to something else are probably small compared to the work and expense involved.

I have not mentioned the issues about other possible uses for the site -- its utility as an educational site, a more open observatory, or a public star party location. Nor have I addressed the issues of private lockers, setting more piers, or placing the loaner scopes out there. I think the primary constraint for our dark sky site is that it is a long way away, and is not very suitable for most people. It is a long, hard drive home after they are tired from being up past a regular bed time. Additional constraints are concerns about security, and the importance of maintaining our good relationship with ranch management.

All of these items deserve and will receive broad discussion at club meetings. We can build or install lockers, if members would use them (assuming we could make them theft-proof and weather-resistant). We could even place one or more of the loaner scopes out there, but how many people without scopes will have keys?

Be sure to look below for renaming suggestions for the dark sky site. Mark your favorite(s), so that the board can select a popular new name that still protects the observatory 's location.

Other observatory issues

by Alane Alchorn

At the February general meeting, broader issues of site use and wider club involvement were discussed. These topics, bulletted below, will be added to each upcoming general and planning meeting agenda.

* From $5-6,000 of club assets can be used to resolve these problems, without injuring our solvency or disrupting other long-term goals.

* Possibly conflicting uses for the scope and site include: astrophotography, educational/public star parties, member-only easy observing, deep sky observing, research/professional observing runs, and automated or robotic applications.

* Some members have requested that additional piers, stands, and pads be poured, so that they can more easily use their own instruments at the site. Likewise, lockable storage units would be helpful for some members.

* Sanitary, more useable lavatory facilities have been requested from time to time.

* The Patron Member system has been questioned and is being reviewed for its benefits to the entire club. This is a sensitive issue that the board wishes to study, first with the Patrons themselves, and then with the general membership.

Club News Notes

Phil Waide is new school star party chair

At the last general meeting, Phil Waide let us know that he is assuming school star party resonsibilities, effective immediately. In February, Phil worked with Rich Green to collect the names and e-mail addresses of interested club members.

The list below contains the requests Phil had received by February 14. You may reach him at:, of by phone at 510 455-6039, if you are interested in helping with school star parties. Thanks, Phil, for taking over this important club outreach program.

Star parties

Phil Waide, our new school star party coordinator, has received the following requests from teachers.

Karen Woodward, science teacher at Marylin Avenue Elementary School, would like to schedule a star party.

Anne Dutton, tech coordinator at Idaho School, is looking for astronomy-related activities for children in grades K-4.

Lisa Burkhart, a teacher at Leo R. Croce Elementary School, would like a star party.

Pat Boyle would like a slide show or star party.

Georganne Nuger and Mary Cunningham at Arroyo Mocho School would lika a star party. Georganne has been involved in Project ASTRO.

Susan Schatz, Kennedy Elementary School in Newark, plans additional star parties.

Ron Wurtz, Jackson Avenue School, also requests a star party.

Victoria Hazard is looking for help with astronomy tours to Hawaii Phone: 800-444-3756

Are you delinquent?

TVS dues became delinquent on February 14, so if you have not paid, your dues are past due. (Dues have not increased this year.)

Renewals and subscriptions may be mailed to our post office box. Magazine subscriptions have been submitted for the year, so it is too late for you to add them to your membership dues.

Delinquent members will also receive a yellow card reminding them to renew.

Fiscal fitness

Club treasurer Gene Nassar reports the following as of February 15:
Checking $4,821.27
CD #1 $3,264.08
CD #2 $2,519.67
CD #3 $2,015.57

Interest rates for the CDs average approximately 4.6%. Only about 50% of the 1997 members had renewed as of February 15, and our 1998 leases to the church and Hilda Moore have not yet been paid. The combined cost of the leases is $800.

Club assets and investments are subject to change, at the direction of the membership as a whole. Please see the newsletter articles regarding the February general meeting and proposed Sky Shack improvements for more information.

Circle these dates

Remaining 1998 general meetings are set for the second Friday of each month as follows:
March 13
April 10
May 8
June 12
July 10
August 14
Sept. 11
Oct. 9
Nov. 13
Dec. 11

Beginning on March 19, monthly planning meetings will change to the Thursday following the general meeting.

AANC Search for Life in the Universe Workshop

Editor 's note: The website referenced in this article could not be accessed on the day we tried. The workshop e-mail notification is reproduced here so that you can attempt to download the flier for yourself.

Astronomical Association of Northern California (AANC) has planned an informative and exciting workshop on April 11, at Lawrence Hall of Science, University of Califor nia, Berkeley.

Contact the AANC workshop website at and click on "Search for Life in the Universe." At the top of the Workshop Web page you will find a link to "Download binhexed Adobe Acrobat Version of this flier" which will allow you to print out an exact duplicate of the flier. You need Adobe Acrobat software to open the flier file. If you do not already have Acrobat on your machine, a link right below the flier link takes you to a page that permits you to download Adobe Acrobat in a version suitable for your particular computer platform.

In a separate e-mail communication, AANC sent the following advance information on workshop topics.

Recent discoveries are changing the way we see our place in the universe:
* in Antarctica, discovery of a meteorite from Mars that may contain signs of life;
* current NASA Mars exploration efforts including Pathfinder, the Sojourner robot, and the Surveyor, part of whose missions are to search for evidence of life on Mars; and
* the discovery of more than a dozen planets outside our solar system.

White Mountains and Yosemite Star Parties

Dave Rodrigues confirms that the White Mountains club star party is set for Thursday July 23, through Sunday July 26. New Moon falls on July 23, so the Milky Way should be spectacular from this vantage. More information, including deadlines and costs, will be available in the near future.

TVS has applied for a variety of dates for the Glacier Point public star party and club viewing nights at Yosemite. As of our deadline, we had not received written approval. Club President Dave Anderson will announce the date(s) as soon as they are released. (Late news: we got Labor Day weekend.)

Auction XVIII

The 1998 SJAA/Bay Area Annual Auction and Swap Meet will be held on Saturday April 4 from noon until early evening. Following the usual format, doors will open at 12 noon, or only slightly before. The swap meet will run until about 3:30, when the room will be rearranged for the auction, running from 4 PM to perhaps 6 PM

Sellers at the swap meet are asked to track their sales, and pay the 10% commission before leaving. (There is a cap of $50 commission on any individual item.) Items for the auction must be pre-registered, and this may be done during the swap meet. The same 10 % commission applies to auction items. A $1 donation is requested of sellers and bidders at the auction.

Houge Park is in south San Jose, near Los Gatos. From Hwy.17, take the Camden Avenue exit. Go east 0.4 miles, and turn right at the light, onto Bascom Avenue. At the next light, turn left onto Woodard Road. At the first stop sign, turn right onto Twilight Drive. Go three blocks, cross Sunrise Drive, then turn left into the park.

President Dave Anderson 510 /661-4249
Vice President
Chuck Grant (510) 449-1500
Bill Burnap (510) 449-4552
Gene Nassar (510) 462-7843
Observatory Director Chuck Grant 510 449-1500
Editor Alane Alchorn 510 455-9464 fax: 510 455-9466
Librarian Chris Cody (707) 747-6550
Eyes on the Skies Mike Rushford

Board Alane Alchorn, Dennis Beckley, Rich Combs, Rich Green, Kathleen Kelly, Russ Kirk, Dave Rodrigues, Debbie Scherrer, Jim Zumstein

Meeting Location Unitarian Universalist Church in Livermore 1893 N. Vasco Rd. 3/4 mile north of I-580

Tri-Valley Stargazers

P.O. Box 2467 Livermore, CA 94551

Membership: 132

Comet Comments

by Don Machholtz


C/1997 J2 (Meunier-Dupouy)
Date (00 UT) R.A. (2000)DecElSkyMag
03-03 21h15.5 m +32° 56 46° M 11.7
03-08 21h22.7 m +32° 37' 46° M 11.7
03-13 21h29.5 m +32° 21' 46° M 11.7
03-18 21h36.0 m +32° 07' 46° M 11.7
03-23 21h42.2 m +31° 54' 46° M 11.7
03-28 21h48.0 m +31° 44' 47° M 11.7
04-02 21h53.6 m +31° 35 48° M 11.7
04-07 21h58.8 m +31° 27' 50° M 11.7
C/1995 O1 (Hale-Bopp)
Date (00 UT) R.A. (2000)DecElSkyMag
03-0 3 04h54.7 m -57° 20' 84° E 8.9
03-0 8 04h54.6 m -56° 33' 83° E 9.0
03-1 3 04h55.1 m -55° 48' 82° E 9.0
03-1 8 04h56.2 m -55° 04' 82° E 9.1
03-2 3 04h57.8 m -54° 22' 81° E 9.2
03-2 8 04h59.9 m -53° 43' 80° E 9.3
04-0 2 05h02.4 m -53° 06' 79° E 9.3
04-0 7 05h05.3 m -52° 32' 78° E 9.4

Only a couple of comets remain in our sky this month. Comet Hale-Bopp fades in our southern sky. Comet Meunier-Dupouy travels through our morning northern sky. The only new finds this past month were made by the SOHO satellite, which monitors the solar vicinity. It discovered four more comets, it has now found 40 in less than two years. Like most of the others, these four comets disappeared after going behind the sun.

Comet hunting notes:

Forty-eight of the last 100 visual comet discoveries were made by amateurs using reflectors ranging in size from 4" to 19.5". The most popular size (16" aperture) was used in 16 finds. Hunters were also efficient, averaging 231 hours per find compared with 391 hours for all visual comet discoveries. All five accidental comet discoveries (Berger, Milon, Hale, Bopp and Tillbrook) were made with reflector telescopes

Orbital Elements

Object: Hale-Bopp Meunier-Dupouy
Peri. Date: 1997 04 01.1347 1998 03 10.4365
Peri. Dist (AU): 0.914008 AU 3.051015 AU
Arg/Peri (2000): 130.5787 deg. 122.6755 deg.
Asc. Node (2000): 282.4653 deg. 148.8429 deg.
Incl (2000): 089.4268 deg. 091.2731 deg.
Eccen: 0.995085 1.000760
Orbital Period: ~2500 years Long Period
Ref: MPC 30738 MPC 30738
Epoch: 1997 12 18 1998 03 08
Absol. Mag/"n": -1.0/4.0 4.0/4.0

Stellar Seller

I'm a telescope in need of a new home. My owner loves me, but doesn't take me out enough. Do you know of anyone looking for nice glass; or, where else I might find some one to take me under the stars? I'm sure my owner wouldn't mind giving me up for less than the usual asking price if he knew I were going to a good home.

These are my specs.: Pocket Scope Design - open truss Newtonian (Sky & Telescope June 1990, p. 665) Galaxy Optic: 14.5 x 2" thick, f/5-ish, Telrad Finder, Tele Vue: Plossl 10.5 mm & 7.4 mm and Barlow 1.8x, Tectron: Ultra-Low rack and pinion focuser, 3- piece collimation tools & book

I would appreciate any help you can offer. I live right next to Mt. Diablo in San Ramon, CA.


Watch this space...

Next month's issue of Prime Focus will contain a feature article on the JPL /NASA on-line ephemeris service HORIZONS. All astronomers, not just comet hunters, will enjoy consulting this service for precise planetary and lunar data. Due to the volume of dark sky site information contained in this edition, we defered the HORIZONS information until it could be presented in full. If you absolutely cannot wait until next month, point your web browser to

Project ASTRO Page

Applications open for Project ASTRO astronomers

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

Project ASTRO helps astronomers form an ongoing partnership with a teacher. Astronomers with an interest in education, and some experience working with children or teens or presenting astronomy to the public, are encouraged to apply. Astronomers attend a two-day summer training workshop with their partner teacher, receive a wide variety of activities and resource materials, work together to plan school year activities and programs and commit to make at least four daytime visits during the school year.

During the school year, visiting astronomers (depending on their interests) can help to lead hands-on activities, serve as a resource for teachers, organize evening observing sessions, create a school astronomy club, present auditorium programs, arrange field trips, or assist with science fair projects. The project's emphasis is on a hands-on, inquiry-based approach that research has shown is most effective in helping students learn the process of science.

The 1998-99 training workshop is scheduled for Friday, August 14 through Saturday, August 15, 1998 at the San Mateo County Office of Education, Redwood City. Participating astronomers are required to attend all or most of the workshop. Classroom visits will begin in fall 1998.

The first application deadline (for preferred placement) is April 11, although applications will be accepted after this date. To request an application call (415) 337-1100 ext. 101 or e-mail For more information contact Nicole Taddune, Bay Area Coordinator, at the Astronomical Society of the Pacific: 415 337-1100 ext. 101 or check out our web site at www.asps

You may also contact Nicole S. Taddune, Bay Area Project ASTRO Coordinator, at Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. Project ASTRO is funded by the National Science Foundation.

What happens if a big asteroid hits the Earth? Judging from realistic simulations involving a sledge hammer and a common laboratory frog, we can assume it will be pretty bad .

- Dave Barry

ASP offers summer position: Astronomy education resource book organizer

Project ASTRO (at the non-profit ASP) has a summer 1998 position available for a candidate with background in both astronomy and education and with good organizational skills. The job involves compiling, evaluating, and rewriting a wide range of hands-on astronomy activities (for grades 4-9) for an update edition of the project's Universe at Your Fingertips resource
notebook. (Project ASTRO is an NSF-supported program to link professional and amateur astronomers with local school teachers, and to develop materials such partners can use directly in the classroom.)

The position is expected to require about three months of intense and interesting full-time employment, working with other project staff in the ASP offices in San Francisco. (The exact start and end times are negotiable.) Tasks will include organizing and requesting astronomy education activities from a variety of sources around the country (many are already in hand), learning about the Project ASTRO approach to activities, evaluating the activities (with help from a panel of teachers), doing any necessary rewriting or supplementary writing so that the activities can stand on their own, re-formating activities into a standard style, and obtaining permissions from copyright holders. Some clerical support will be available.

Qualifications include: a degree in astronomy (or equivalent background); some experience teaching science; familiarity with hands-on activities ; good writing skills ; and the ability to work on a complex project in an organized way without constant supervi sion. Salary will be commensurate with experience. (Note that this is a one-time summer position.)

Interested candidates should send a letter describing their interest and qualifications, together with a resume to: Andrew Fraknoi, Director, Project ASTRO, A.S.P., 390 Ashton Ave., San Francisco, CA 94112. For futher information, write to the ASP, call (415) 337-1100 ext. 120, or e-mail: fraknoi

The Consortium for Undergraduate Research and Education in Astronomy will offer a summer program in astronomy and astrophysics, August 12-25. Students will live and work on Mount Wilson near Los Angeles. The application deadline is April 15. Access the website at

Sky Shack name change ballot

After reading the articles regarding our club dark sky site and observatory, please complete the opinion poll and ballot below. If you have not already renewed your 1998 membership, please complete that portion on the reverse side, as well. Family members should photocopy this form as needed. Send your response to the post office address. Results will be published in the May Prime Focus.

The board will select the final name from the top five finishers in this balloting. Protecting the privacy of our leased site is the top priority for TVS.

____ Pine Shack Obs.
____ Hidden Hills Obs.
____ Red Mountain Obs.
____ Cedar Ridge Obs.
____ The Dark Site
____ Lick Obs. East
____ Eastern Mt. Hamilton Obs.
____ San Antone Valley Obs.
____ Mines Road Obs.
____ Jack's Obs.
____ Hot Hill Obs.
____ Keck III
____ Middle of the Ranch Obs.
____ Celestial Temple Obs.
____ Other ________ ____________ ____________ _________

Dark sky site opinion poll

Rank your preferred uses for the club's observatory and dark sky site, with #1 as your highest choice. Please attach a separate sheet if you would like to send detailed comments.

____ Astrophotography, using the club scope
____ Astrophotography, using your own instruments
____ Solar system/planetary observing
____ Comet hunting
____ Open house/star party events
____ Research/professional quality observations
____ Visual astronomy, using the club scope
____ Visual astronomy, using your own instrument
____ Unaided eye/binocular observing
____ Social observing events with other amateurs
____ Other, as noted below ________ ____________ ____________ ____________ _______ ________ ____________ ____________ ____________ _______

Tri-Valley Stargazers Membership/Renewal Application
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