Prime Focus

The newsletter of the Tri-Valley Stargazers May 1998.
Translated (roughly) from postscript into HTML for your browsing and downloading pleasure.

TVS presents


Lunar Prospec tor mission upda te


Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.


May 8, 1998
Conversation, 7:00 PM Program begins, 7:30 PM

Who: You and your family

Alan Binder, principal investigator

IN THI S ISSUE May general meeting
Club news and notes
What's Up
Comet Comme nts
JPL epheme rides

Has the tiny low-budget spacecraft Lunar Prospector really found water-ice at the Moon's poles? "Would I bet my house? The answer is, \221yes! ' We are certain that water is there. The uncerta inty we have is how much." Alan Binder, speaker at the TVS May general meeting, is positi ve that somewhere between 10 and 300 million tons of water-ice ri me craters of the lunar poles.

At this early point in the mission and its data analysis, this range may be in error by as much as an order of magnitude, because Luna r Prospector is the first interplanetary mission to employ a neutron spectroscopy tool to measure water. No previous precis e models exis t to describe exactly how neutrons behave on the lunar surface. Binder believes that, "the answer is in the data... it's just a matter of finding out what it is."

Lunar Prospector's overall mission places scientific exploration of the Moon as its highest priority. Researchers expect that the mission will contribute major new understandings of the origin, evolution, and current state of the Moon. Join us at the May meeting to hear the latest from the project's pri ncipal investigator.

The Lunar Prospect or "footprint," or mapping area at each pole is out lined in white. The footp rint is roughly 150 km by 175 km. Scatt ered water-ice has been ident ifie d insid e the craters at bot h poles. (Lunar Prospect or, NASA)

Fremont Pea k appeal In the April issue of SJAA Ep hemeris , the San Jose
Astronomical Association revealed that damage to Frmont Peak's 30-inch Challenger Telescope is estimated to be approximately $10,000. This estimate was made by the Fremont Peak Observatory Association (FPOA), following a series of winter storms. FPOA has opened a repair fund and seeks donations from local amateur astronomers. Contact


Attention, astrophoto graphers

TVS webmaster Chuck Grant announces that the club has recently acquired access to an Internet server with about a gigabyte of dis k space and no bandwidth limits. He believes that astrophotos taken by club members can be posted to the page.

Photos of other club activities, such as star parties at White Mountains or Glacier Point, public service astronomy at schools and parks, and snapshots taken at meetings, can also be put on the Web.

If you are interested in putting astrophotos or club pictures on the site, contact Chuck at 925 /449-1500.

Ba lancing the boo ks
Club librari an Chris Cody asks members to check their astronomical collections for any TVS lending library materials that may be overdue. Circulating materials are borrowed from one general meeting to the next, unless the member has made special arrangements with Chris to keep an item for a longer period.

If you are holding delinquent books, tapes, or videos, please return them to the May general meeting. Those who

cannot attend the May meeting are asked to call Chris at (707) 747-6550.

Springtime skies
Now that El Nino is diss ipating, maybe we can catch a glimpse of the beautiful springtime galaxies. The portable club scopes and binoculars make observing easy and fun, even for beginners.

In his role as TVS loaner scope czar, Chuck Grant matches members with telescopes. Our array of light buckets
is available for rent from one general meeting to the next. For only $15 per month ($5/ month for student members), you can enjoy big aperature at a small pri ce.

In fact, your scope rental can be free if you share your loaner gear at an public or school star party. Remember that the club collects a refundable $50 deposit for each scope rented. Your check will be returned uncashed when the scope comes back.

Reve nue recap
Pending improvements to our dark sky site and capital investments in club equipment, our financial status (Continued on page 5)

President Dave Anderson 510 /661-4249 Vice President Chuck Grant (925) 449-1500 Secretary Bill Burnap (925) 449-4552 Treasurer Gene Nassar (925) 462-7843

Board Alane Alchorn Dennis Beckley Rich Combs Rich Green Kathleen Kelley Russ Kirk Dave Rodrigu es Debbie Scherrer Jim Zum stein

Observatory Director Chuck Grant grant@

Editor Alane Alchorn
925 / 455-9464 fax: 925 / 455-9466 circlewing@

Chris Cody (707) 747-6550

Eyes on the Skies Mike Rushford

http://www. hooked. net/~tvs/

Meeting Location Unitarian Universalist Church in Livermore

1893 N. Vasco Rd. 3/4 mil e north of I-580

E-mai l tvs@hook

Tri-Valley Stargazers

P.O. Box 2467 Livermore, CA 9455 1
Membership: 193

Phil Waide, our school star party coordinator, has received requests for May star parties. Members interested in public service atronomy in the schools should contact Phil at (510) 455-6039.

Public star parties are coordinated by Jim McIntire, who announc es the following events:

June 20
, Sycamore Grove Park in
June 26-2 8,
Camp Shelly at Lake
July 18
, Sycamore Grove Park in
August 15
, Sycamore Grove Park
in Livermore
August 21 -23
, Camp Shelly at
Lake Tahoe
September 4-6
, Glacier Point at
September 26
, Sycamore Grove
Park in Livermore To reach Jim, e-mail him at jim911 @pac or call (209) 836-3836.

The White Mountains club star party is set for

Thursday, July 23
through Sunday, July 26.
Acc limation at Grand View Campgrounds is planned for the first evening. Dave Rodrigues will announc e deadlines and costs at a future meeting.

Club News and Notes Star Parties

2 Sat Astronomy Day.
3 Sun First Quarter Moon 3:04 AM PDT.
4 Mon Mercury at greatest western elongation (27 ° ) in morning sky.
8 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). 9 Sat Iota Virgi nis (mag. 4.8) occulted by Moon 12:54 AM
10 Sun Mother's Day.
11 Mon Full Moon 7:29 AM
14 Thu TVS Planning Meeting 7:00 PM Round Table Pizza, 1540 First St., Livermore
(in Orchard Supply/Longs/Safeway shopping center). 16 Sat Open House at the Sky Shack. Meet at the corner of Mines and Tesla Roads, Livermore, at 6:00 PM
Good weekend for observing: no moon until 12:40 AM 18 Mon Last Quarter Moon 9:35 PM
20 Wed Jupiter 0.4° north of Moon (occulted in Australia).
22 Fri Venus 1.7° north of Moon.
Riverside Telescope Makers Conference begins. (Info: (909) 948-2205 or m.) 23 Sat Excellent weekend for observing.Sat urn 1.7° north of Moon.
25 Mon Memorial Day. New Moon 12:32 PM
27 Wed Pluto at opposition (mag. 13.7 ).
28 Thu Venus 0.3° north of Saturn.
31 Sun Regulus 1° north of Moon (occulted in New Zealan d). Galileo flyby of Europa.

1 Mon First Quarter Moon 6:45 PM PDT.
6 Sat Asteroid 6 Hebe (mag. 9.4) at opposition.

Some Deep Sky Objects

M81 & M82 Two fine galaxies in Ursa Maj or. The first a fine spiral; the second irregular,
elongated with a dark band running through it. M97 & M108 The Owl nebula and a nearby galaxy. M97 is a large, somewhat faint planetary in Ursa Maj or.
M65 & M66 Two nice galaxies in Leo with the large, fainter, edge-on spiral NGC 3628 in the same field.
M95, M96 & M105 A triplet of galaxies less than a degree apart in Leo.
M51 The Whirlpool galaxy in Canes Venatici. One of the best galaxies in all the sky. Peculiar appendage NGC 5195.
M3 A fine globular cluster in Canes Venatici.
NGC 324 2 The Ghost of Jupiter in Hydra. A nice planetary.
M104 The Sombrero galaxy in southern Virgo.
M58, M59, M60, M84, M86, M87, M89, M90, etc. The Virgo cluster! A swarm of mostly fairly faint galaxies of all sorts.
For an excellent star-hopping tour of the heart of the cluster, see Alan M. Mac Robert, "Mastering the Virgo Cluster," Sky & Telescope, May 199 4, p. 42-47. 3C273 The brightest (and fi rst-discovered) quasar. In Virgo. Diffi cult, at mag. 12-13. (Red shift 0.158 ).
M13 The Great Hercules Cluster! Look for the mag. 12 galaxy NGC 6207 in the same field.
M92 Another fine globular cluster in Hercules, often overlooked.

What's Up in May Dave Anderson

C/1997 J2 (Meuni er-Dupouy)
Date (00 UT) R.A. (2000)DecElSkyMag 05-02 22h19.5m +30° 55 60° M 11.6
05-07 22h22.5m +30° 49 63° M 11.6
05-12 22h25.1m +30° 41' 66° M 11.6 05-17 22h27.3m +30° 33' 69° M 11.6 05-22 22h28.9m +30° 22' 73° M 11.5 05-27 22h30.1m +30° 10' 76° M 11.5 06-01 22h30.8m +29° 55 80° M 11.5
06-06 22h31.0m +29° 37' 84° M 11.5
C/1995 O1 (Hal e-Bopp)
Date (00 UT) R.A. (2000)DecElSkyMag 05-02 05h23.8m -50° 26' 75° E 9.7 05-07 05h28.1m -50° 10' 75° E 9.8 05-12 05h32.6m -49° 57' 75° E 9.9 05-17 05h37.2m -49° 48' 74° E 9.9 05-22 05h41.9m -49° 42' 74° E 10.0 05-27 05h46.7m -49° 39' 74° E 10.1 06-01 05h51.5m -49° 39' 74° E 10.1 06-06 05h56.5m -49° 42' 74° E 10.2 The Solar Heliosp heric Observatory (SOHO) satellite has detected three more comets, while a faint one was discovered during an asteroid search. This object, Comet C/199 8 G1 (Linear) has a nuclear magnitude of 18 and is not expected to brighten.

The Hubble Space Telescope has determined that the nucleus of Comet Tempel-Tuttle is only about two miles across. This comet is responsible for the Leonid Meteor Shower each November.

Comet activity remains low this month. Comet Hale-Bopp rides deep in the southern sky, about 450 million miles from Earth. Comet Meunier-Dupouy, a bit closer, is in our morning sky.

COMET HUNTING NOTES: The SOHO satellite, which is in solar orbit and monitors the sun, has discovered 44 comets. Forty-two of these are sungrazers; they go very close to the sun. SOHO generally images them for only about a day or two, and then the comets merge into the sun, never to be seen again. They have not been observed from Earth. This satellite is presently our most active comet discoverer, finding about 20 new comets per year.

Ephemerides Orbital Elemen ts

Object: Hale-Bopp
Peri. Date: 1997 04 01.1 347
Peri. Dist (AU): 0.9140 08 AU
Arg/Peri (2000): 130.57 87 deg.
Asc. Node (2000): 282.46 53 deg.
Incl (2000): 089.42 68 deg.
Eccen: 0.9950 85
Orbital Period: ~2500 years
Ref: MPC 3073 8
Epoch: 1997 120 18
Absol. Mag/"n": -1.0/4.0

Object: Meunier-Du pouy
Peri. Date: 1998 03 10.4 365
Peri. Dist (AU): 3.0510 15 AU
Arg/Peri (2000): 122.67 55 deg.
Asc. Node (2000): 148.84 29 deg.
Incl (2000): 091.27 31 deg.
Eccen: 1.0007 60
Orbital Period: Long Period
Ref: MPC 3073 8
Epoch: 1998 03 08
Absol. Mag/"n": 4.0/4.0

Comet Comments Don Mac hhol z Sky Shack name change delayed one month Due to the early deadline of this month's Prime Focus , the new name for our dark sky site
and observatory will be announced in next month's newsletter. We apologize for the timing; however, this edition was prepared before the April planning meeting was held.

Likewis e, members who joined TVS between the March and April general meetings will be introduced to you in our next edition. Please remember that the June newsletter also carries an early deadline. Submissions must be received no later than May 9, 5:00 PM You may send e-mail or faxes per the information in the box on page 2. Typed copy must be delivered to Circle Wing, 184 Airway Blvd., Livermore, CA 945 50.

Fremont Pea k appea l
Denni Medlock, FPOA treasurer, at her e-mail address epoch@maj Her telephone number is 510 /339-9224.

Work parties to restore the observatory are also planned once the rains stop. Donat ions of your cash or time and energy are equ ally appreciated.

More club news and notes (Continued from page 2) remains essentially unchange d from last month. Club funds are divi ded between the checking account and three certificates of deposit as follows.

Checking account: $4,279.33
CD #1: $3,276.27
CD #2: $2,519.67
CD #3: $2,023.53

At the May general meeting, club officers will present potential investment plans for the balance of this year.

Public service astronomy seed money offere d

Rich Combs, our Amate ur Telescope Makers Workshop wi zard, sends the following announcem ent regarding funds available to encourage public service astronomy.

The V.M. Slipher Committee offers up to $4,500 as an award for projects that enhance public understanding of astronomy. Grants will fund projects that:

1. request seed money for programs that will continue beyond the funding period; or,

2. provide programs/service to more than a single group (no requests for equipment to serve a single classroom or school building, please).

Applications must be post marked by May 22, 1998. Notifi cation of grants will be made around July 31.

For full guideli nes contact: Dennis Scha tz, chairman, V.M. Slipher Committee Pacifi c Science Center, 200 Second Ave. North Seattle, WA 9810 9, or call 206 /443-2001.

What's up in May (Continued from page 3)


Mercury Nearly lost in morning twilight early in the month. Venus Low in east before sunris e.
Mars Behind the Sun.
Jupiter Low in east before sunris e.
Saturn Lost in morning twilight.
Uranus Ris es near midnight; south-southeast in morning
sky. Neptune Rises near midnight; south-southea st in morning sky. Pluto At opposition; up all night.

Messier and Caldwell objects

UMa M101 (Pinwheel Galaxy)
CVn M3 (globular cluster), M51 (Whirlpool Galaxy),
M63 (Sunflower Galaxy), C29 (galaxy) Com M53 (globular cluster), C35 (galaxy)
Boo C45 (galaxy)
Hya M83 (galaxy), C66 (globular cluster)
Cen C77 (Centaurus A galaxy),
C80 (Omega Centauri)

Astro events calen dar In addition to the scheduled TVS events, you may enjoy particip ating in these other stellar happenings.

May 2
Eastbay Astronomical Society Astronomy Day,
Chabot Observatory, Oakland. 1-5 PM and 7-11 PM

May 20-2 2
IAPPP Anual Meeting, Mile High Lake
Arrowhead Resort. Call Bob Bell, (909) 337-5080.

May 22-2 5
Riverside Telescope Makers Conference,
Camp Oakes, Big Bear. Call 909 /948-2205.

May 29-3 0
Clever Planetarium Summer Astronomy
Program, San Joaqu in Delta College, Stockt on. Call 209 /954-5110.

June 25-July 1
Astronomical Society of the Pacifi c
110th Annual Meeting, Albuquerque, NM. See page 6 for more details.

ASP and Proje ct ASTRO News and Notes The Astronomical Society of the Pacifi c is an international scientific and educational membership society for astronomers, educators and the public. ASP publishes a scientific journal, a popular magaz ine, and newsletter for teachers, holds meetings and workshops, runs a mail-order catalog service for educational materials in astronomy, develops educational materials, and works with the media and the public. The Society is headquartered in its own building in San Francisco, near San Francisco State University, and has a staff of approximately 20.

11 0th Annual Meeting information
Expand your universe at the ASP 110 th Annual Meeting, set for June 25 to July 1 in Albuque rque, NM. This year the meeting will be co-hosted by Astronomy magazine and the
University of New Mexico.

The week-long meeting will feature experts on astronomy and astronomy education, a workshop for teachers of students in grades 3-12, symposi a for educators and scientists, a keynote lecture by astronaut and educator Dr. Story Musgrave, and a tour of the Very Large Array Telescope (VLA).

The scientific sympos ium will discuss "Adapt ive Optics and Interferometry in the 21st Century." The educational synposi um topic is, "Teach ing Astronomy to Non-Science Majors." Both symposi a will consis t of invited presentations, contributed posters, and panel discussions.

"Universe \22198: An Astronomy Exposition," co-sponsored by Astronomy magaz ine, consists of two days of talks on
new developments in astronomy, histori cal subjects, hands-on activiti es for children, an exhibi t hall, book signings, a raffle, a si lent auction, and door prizes.

New this year, a "Me et the Astronomers" section, is an informal gathering of the speakers on Sunday afternoon. They will meet in the exhibi t hall to answer general questions on astronomy and their current projects.

Registration fees depend on the number of meeting events you wish to attend. You may download a registration form and fee schedule from the ASP website at For questions regarding the annual meeting, call ASP at (415) 337-1100, ext. 109, between 9:00 AM and 4:00 PM PDT.

Bay Area Project ASTRO Coor dinator
ASP seeks a full-time Bay Area coordinator for Project ASTRO, an innovative project funded by a three-yea r grant from the National Science Foundation and NASA. Project ASTRO links amateur and professional astronomers with educat ors and students in grades 4-9. After being trained with their partner educators, astronomers visit schools and community organizations as volunteers to help improve science education.

Started as a pilot project in California, Project ASTRO is now growing in the Bay Area and has expanded to ten sites nationally.

The Bay Area Project ASTRO coordinator, in collaboration with the Bay Area Project ASTRO director, manages Project ASTRO in the Bay Area and assists with the educational activities of the national Project ASTRO expansion. Posi tion resonsibilities include a variety of collaborative, management, and editori al tasks dedicated to promoting Project ASTRO. Fund raising managemen t is also an assigned responsibility.

Minimum requirements: Bachelor's degree and at least two year's experience in science education or other educat ional project or program; excellent research, writing, and oral communication ski lls; enthusiastic, outgoing, positi ve, and collaborative interpersonal style; organizational skills and strong motivations to work without extensive supervision; Macintosh experience and knowledge of Filemaker Pro and MS Word; and some educat ional background in astronomy (such as a college-le vel astronomy class, weekend extension course, a long-term personal interest, etc.) preferred.

The salary is $27-32,000/ year, plus benefi ts. To apply, send a letter explaining your interests and qua lif ications, a resume and three work references (supervis ors) to:

Shannon Lalor National Project ASTRO coordinator Astronomical Society of the Pacific 390 Ashton Avenue, San Francisco, CA 9411 2

Applications should be postmarked by May 15, 199 8.

NASA'a Jet Propulsion Laboratory (JPL) offers an on-line solar system ephemeris service (HORIZONS) for the benefit of anyone who wishes to know the physical characte ri stics and positions of the solar system bodies. Physical data and position prediction data are available for the 9 planets, 61 natural satellites, and more than 15,00 0 small bodies (comets and asteroids ). Planetary, lunar and small-body positional information (ephemerides) are computed over the interval AD 160 0 through AD 2200. Ephemerides of the natural satellites are available over shorter intervals (from 2 to 50 years) that vary in length in accordance with their orbital accu racy. Recently the JPL planetary and lunar ephemeris files have been extended to the six- millennium interval -300 0 through +300 0, making this HORIZONS system of potential interest to histori ans of astronomy.

The HORIZONS system can conduct parametric searches of the comet/asteroid database, matching combinations of up to 40 different parameters. Ris e, transit, and set can be identified to the nearest minute. More than 70 different observational and physical aspect qua ntities can be output at requested intervals for both geocentric and topocentric observing sites. Over 600 Earth stations are on fi le, and users can input their own topocentric coordinates.

Three basic types of ephemerides can be requested: 1. observables (geometric, astrometric and apparent RA/DEC, AZ/EL, physical aspect, angles, illuminati on, etc.); 2. osculating orbital elements; and, 3. Cartesian state vectors (centered at sun or any planet's center). Output is returned to the user via e-mail, FTP, or Kermit protocols and ephemerides can be produced in a format suitable for import into spreadsheets.

Three different techniques allow access the HORIZONS system.

Telne t
(full access, interactive prompt-based interface)
1. Telnet directly to the system (telnet 6775 ). No account or password is required. (There is a space before the port number "6775 "). 2. Specify an object to get a summary data screen. 3. Follow prompts. At any prompt, type "?" or "?!" for short or long explanations. 4. Follow prompts to transmit results to your system by e-mail, FTP, or Kermit.

E-ma il
(full access, batch interface)
1. Send e-mail to horizons@ss with subject "HORIZO NS-BATCH- LONG" 2. An example command file will be e-mailed back to you. 3. Edit this text fi le, then e-mail it back with the subject header "J OB-SUBMITTAL " 4. Results of your request are e-mailed back to you.

(partial access, interactive GUI interface)
1. Point your web browser to: The Web page (http://ss, created by Alan Chamberlin, also gives additional tables on close-Earth approaches of small bodi es (past and future), great comets in his tory, meteor showers, plots of small bodi es in the inner and outer solar system, small-body observation identif ication, asteroid discovery circumstances, etc.

Alth ough the HORIZONS system has been designed with on-line document ation, users guides can be requested by anonymous FTP, e-mail, or a download from the Web.

Anonymo us FTP
(Postscri pt file)
ftp://ss ftp://ss

E-ma il
(Posts cript fi le)
Mail a message to "" with subject "HORIZON S-DOC- PS"
E-ma il
(ASCII text - unformatted)
Mail a message to "" with subject "HORIZON S-DOC- TEXT"

Web downlo ad
(Posts cript fi le)
Web downlo ad
(i ndexed access)

Comments and suggestions for improving the HORIZONS system are welcome, and should be addressed to the HORIZONS creator and system engineer, Jon D. Giorgi ni (jdg@tycho. Simi lar comments and suggestions for the Web page should be addressed to Alan B. Chamberlin (

Need dependa ble ephemerides? JPL can help!

Prime Focus Tri-Valley Stargazers Newsletter P.O. Box 2476 Livermore, CA 945 51

Tri-Valley Stargazers Membership/R enewal Application Member agrees to hold Tri-Valley Stargazers, and any cooperating organizations or landowners, harmle ss from all claims
of liability for any injury or loss sustai ned at a TVS function.

Name______ ____________ ____________ ________Phone_ ____________ ____________ ____e-mail________ __________ ______

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Do not release my: ____address, ____phone, or ____e-m ail information to other TVS members. Membership category:___ _______$40 Patron Member____ ______$25 Family__________$20 Single___________$5 Student
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$__________Tax-deductible contribution to Tri-Valley Stargazers $__________TOTAL Return to: Tri-Valley Stargazers. P.O. Box 2476 Livermore, CA 945 51. Membership informati on: Term is one calendar year, January through December. Student members must be less than 18
years old. Patron membership ($4 0) is in addition to a family or single membership. %%[ Page: 1 ]%% %%[ LastPage ]%%