Prime Focus

Tri-Valley Stargazers June 1998


TVS presents
Club news and notes
What's Up
Comet Comments

TVS presents

What: Machismo in the Late 20th Century
Where: Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.
When: June 12, 1998 Conversation, 7:00 PM Program begins, 7:30 PM
Who: You and your family, Dennis Zaritsky, Ph.D.

Among the seven research projects currently taking Dennis Zaritsky's telescope time is The Magellanic Cloud Photometric Survey. The project is surveying the central regions of the Large and Small Megellanic Clouds, using drift-scanning instruments with CCDs.

According to Dr. Zaritsky, the "principal scientific aims for the project are to: study the star formation history of the Clouds, in stellar clusters and in the field; compare the spatially resolved and integrated properties of the Clouds; and study the interaction between massive stars and the interstellar medium." Project researchers intend to complete their work within five years, and then release their data as an atlas accompanied by astronomical images.

The Magellanic Clouds are signigicant because they provide an intermediate point between gallactic research, in which individual stars can be observed but their aggregate effect cannot be, and extragalactic investigations that yield information about the aggregate at the expense of individual stars.

The Magellanic Cloud Photometric Survey will catalogue central structures within the Large and Small Clouds, down to a limiting magnatude of V=21. This U-band image captures a portion of an emission line region. (UCO/Lick Observatory, MCPS)

TVS members respond

During the two most recent planning meetings, the board has devoted most of its time to discussions about our dark sky site, and the use of club assets to improve our telescope and observatory. We wish to thank the following members who have written cogent opinions about the club, the observatory, and public service astronomy: Lawrence Brown, Gert Gottschalk, Chuck Grant, Robert Shelton, Dave Sworin, and Chuck Vaughn.

Mark your calendar now for the August 14 summer barbecue and all-club meeting. The board will present its proposals for general discussion and a club vote. Each member will have the opportunity to vote on every issue involving club funds and observatory improvements. We will also select the new observatory name at this meeting.

New member update
The hope of spying spring galaxies brings the following new memebers to TVS: Gene Cross, the Ed and Allison Clark Family, Robert Brauer, Chris Johnson, Morris Jones, Jim Alves, and Jess Squires.

Cash count
A glance at the ledger reveals our accounts to contain:
Checking $4,376.44
CD #1 $3,301.20
CD #2 $2,558.50
CD #3 $2,023.53

We thank Conrad Stolarski for his generous donation to the club. In addition, an anonymous donor has presented 18 name badges for use at start parties and other public functions. The badges are engraved with the names of board members and committee chairs. These name tags look very professional, and the club gratefully acknowledges this gift.

Our annual non-profit tax statement has been filed with all appropriate agencies. A $30 non-profit domestic corporation statement was completed in May, per state requirements.

At the May planning meeting, the board approved the purchase of a comprehensive package of slide sets to be used at school and public star parties. This purchase totaled $221.65. Many of these slides will be shown at future general meetings.

Board positions open
Club secretary Bill Burnap is unable to complete his term, so members are invited to apply for this position. The secretary is a voting board member who attends planning meetings and keeps formal minutes of the business transacted there.

The time committment for a typical month is about six hours, including attendance at the general and planning meetings, and transcription and copying of the monthly minutes.

Membership: 193

Phil Waide, our school star party coordinator, is scheduling school star parties thoughout this month. Interested members should contact Phil at (925) 455-6039.

Public star parties are arranged by Jim McIntire, who announces the following events:
June 20, Sycamore Grove Park in Livermore
June 26-28, Camp Shelly at Lake Tahoe
July 18, Sycamore Grove Park in Livermore
August 15, Sycamore Grove Park in Livermore
August 21-23 , Camp Shelly at Lake Tahoe
September 4-6, Glacier Point at Yosemite
September 26, Sycamore Grove Park in Livermore

To reach Jim, e-mail him at or call (209) 836-3836.

The White Mountains club star party is set for Thursday, July 23 through Sunday, July 26. Acclimation at Grand View Campgrounds is planned for the first evening. Dave Rodrigues announces that the cost will be $45 per person per night ($135 per person for all three nights).

Comet Commets

Don Machholz


C/1997 J2 (Meunier-Dupouy)
Date (00 UT) R.A.(2000)DecElSkyMag
06-01 22h30.8m +29° 55 80° M 11.5
06-06 22h31.0m +29° 37' 84° M 11.5
06-11 22h30.6m +29° 15' 88° M 11.5
06-16 22h29.7m +28° 49' 92° M 11.4
06-21 22h28.2m +28° 18' 97° M 11.4
06-26 22h26.1m +27° 41' 101 ° M 11.5
07-01 22h23.4m +26° 58' 106 ° M 11.4
C/1998 H1 (Stonehouse)
Date (00 UT) R.A.(2000)DecElSkyMag
06-01 12h39.7m +49° 06' 92° E 12.6
06-04 12h33.8m +49° 34' 89° E 12.7
06-07 12h28.8m +49° 22' 86° E 12.9
06-10 12h24.7m +50° 11' 83° E 13.1
06-13 12h21.3m +50° 23' 81° E 13.2
06-16 12h18.7m +50° 32' 79° E 13.4
C/1995 O1 (Hale-Bopp)
Date (00 UT) R.A.(2000)DecElSkyMag
06-01 05h51.5m -49° 39' 74° E 10.1
06-06 05h56.5m -49° 42' 74° E 10.2
06-11 06h01.4m -49° 48' 74° E 10.2
06-16 06h06.4m -49° 58' 74° E 10.3
06-21 06h11.4m -50° 10' 74° E 10.3
06-26 06h16.4m -50° 26' 74° E 10.4
07-01 06h21.4m -50° 44' 74° M 10.4
C/1998 J1 (SOHO)
Date (00 UT) R.A.(2000)DecElSkyMag
06-01 06h37.4m -13° 47' 47° E 5.5
06-04 06h53.6m -17° 53' 51° E 6.0
06-07 07h08.9m -21° 30' 54° E 6.5
06-10 07h23.4m -24° 41' 57° E 6.9
06-13 07h37.2m -27° 30' 60° E 7.3
06-16 07h50.4m -29° 59' 62° E 7.6
The SOHO satellite found two more comets, one of which should be visible in the evening sky, with Southern Hemisphere observers favored. Positions are given below.

Patrick Stonehouse of Wolverine, MI discovered a comet on April 22, his first such find. He used a 17.5 ", f/4.5 reflector at 62x. C/1998 H1 (Stonehouse) is in a highly-inclined orbit and remains in the northern sky.

COMET HUNTING NOTES: Patrick Stonehouse does not systematically sweep the sky for comets, but does so only occasionally at the end of some of his observing sessions. I suspect there are numerous other amateurs who conduct comet hunting on a casual basis. For Stonehouse the search lasted about 100 hours over 20+ years.

Orbital Elements

Object: Hale-Bopp Meunier-Dupouy Stonehouse SOHO
Peri. Date :1997 04 01.1347 1998 03 10.43651998 04 14.2051998 05 08.837
Peri. Dist (AU): 0.914008 AU 3.051015 AU 1.48678 AU 0.16264 AU
Arg/Peri (2000): 130.5787 deg. 122.6755 deg.001.1 46 deg. 110.666 deg.
Asc. Node (2000): 282.4653 deg. 148.8429 deg.222.1 03 deg. 349.963 deg.
Incl (2000): 089.4268 deg. 091.2731 deg.104.6 68 deg. 58.08 9 deg.
Eccen: 0.995085 1.000760 1.0 1.0
Orbital Period: ~2500 years Long Period Long Period? Long Period
Ref: MPC 3073 8 MPC 30738 IAUC 6887 MPEC 1998-J14
Epoch: 1997 12 18 1998 03 08 1998 04 14 1998 05 09
Absol. Mag/"n": -1.0/4.0 4.0/ 4.0 10.0/ 4.0 7.0/4.0
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