Prime Focus

The newsletter of the Tri-Valley Stargazers February 1997.
Translated (roughly) from postscript into HTML for your browsing and downloading pleasure.
The dark spot on Jupiter's clouds is the shadow of Io, as Io orbited on July 24, 1996. The shadow is roughly 3,640 kilometers (2,262 miles) in diameter. Bright patches on Io highlight sulfur dioxide frost regions. (J. Spencer (Lowell Observatory), NASA, HST)


February general meeting
Club news notes
What's Up in February
Comet Comments
Light pollution warning
Membership renewal/application form

TVS presents

What: Extrasolar planets
When: February 21, 1997 Conversation, 7:00 PM Business meeting, 7:30 PM
Who: Paul Butler, Ph.D.
Where: Unitarian Universalist Church in Livermore, 1893 N. Vasco Rd.

Dr. Butler and Geoff Marcy, Ph.D. have spent the last ten years searching for planets orbiting suns beyond this solar system. They use a technique that measures the Doppler shift in starlight caused by an orbiting planet.

Since 1987, they have monitored 120 stars in an attempt to indirectly detect planetary companions of those suns. At the telescope, Butler and Marcy measure the change in wavelength of the light coming from a specific star over a course of days, months, or years. The wavelength change is the Doppler light shift resulting from the influence of the mass of the companion planet. For example, our sun wobbles in space due to the effect of Jupiter's orbit by about 12 meters per second.

On October 6, 1995, the first identified companion was announced by Swiss astronomers Michel Mayor and Didier Queloz. It was located at the star 51 Pegasi. Butler and Marcy independently confirmed the Swiss discovery, making this the first verified planet ever found orbiting a solar-type star. Since then they have located another six planetary companions.

Club News Notes

LARPD thanks TVS

Bob Braddy, former club vice-president, received this letter thanking the club for its work with the Livermore Area Recreation and Park District (LARPD).

Dear Bob: I thought that the start of the new year was a good time to drop you a line to thank you and all of the Tri-Valley Stargazers for the wonderful presentations you made up at Camp Shelly this summer.

Every campground visitor I talked to that weekend was full of praise for the efforts of your group to make a mysterious world seem just a little bit closer to our own earthbound lives.

Your slide presentations and your generosity in allowing our campers to use your telescopes really gave them an "up close and personal" look at the heavens. Our goal at the campground is to provide families and visitors with an enriching camping and recreational experience. Your efforts really made a difference to a great number of people up at Camp Shelly this year, and we hope to see you folks up at the campground this summer.

Once again, thanks to all of the Tri-Valley Stargazers and their families for all of your efforts, and best wishes for the new year.

Pat Sotelo Park Ranger

New members joining the club during January are: James Jardin, Stephen DiZio, and the Brad Johnson family. At the next general meeting introduce yourself, and help make these newcomers feel at home.

Meeting dates
General Meeting nights are now the third Friday of each month: February 21, March 21, April 18, May 16, June 20, July 18, Aug. 15, Sept. 19, October 17, November 21, December 19.

Fiscal fitness
It's time to limber up your check-writing hand if you have not already paid 1997 club dues. Please see the renewal application on page 8 and also complete the Member's Questionnaire on page 7.

January's financial statement looks so strong because it reflects dues received year to date, while our annual rental obligations are not yet payable.
Checking account $6,233.47
Money Market $1,202.24
CD $3,111.97
Sky Shack key deposits are retained in the CD, and represent refundable-on-demand financial liabilities.

We appreicate the help!

Two club members have stepped forward to help run our organization. Thank you to Chuck Grant and Linda Cody. Chuck, who is already serving as our vice-president, updates the Web Site monthly. The new pointers are really useful. Thanks, Chuck.

Linda Cody will keep us well-fed at the general meetings. As the new hospitality chair, she will be supplying us with plenty of cookies and coffee during meeting breaks. Be sure to thank her personally in February.

Volunteers needed
OK, so the pay is lousy; but think how good you'll feel helping TVS. The club needs three stalwart members willing to chair committees for 1997.

The school star party committee should be in place by next month. This chair coordinates requests from Tri-Valley teachers using astronomy in their science modules. The chair need not attend school parties in person, but arranges for members and scopes as requested.

Earl Mack will be retiring as the club's recording secretary. By the March planning meeting, the board would like to have a new secretary to keep minutes. This chore involves eating pizza and drinking soda once a month, while recording board businesss.

Finally, TVS is in real need of a programs/speakers chair. This is a terrific opportunity to talk with astronomy researchers about their current work. The program chair selects topics for general meetings, and confirms the speaker's availability.

If you can assist with any of these jobs, contact President Dave Anderson at 510 /661-4249; or see any board officer as soon as it is convenient.

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
(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

Comet Comments

by Don Machholtz


C/1995 O1 (Hale-Bopp)
Date (00 UT) R.A. (2000) Dec El Sky Mag
02-06 19h53.4m +18° 01' 40° M 1.1
02-11 20h07.8m +20° 50' 41° M 0.7
02-16 20h24.8m +24° 05' 43° M 0.5
02-21 20h44.1m +27° 31' 44° M 0.0
02-26 21h06.9m +31° 10' 45° M -0.1
03-03 21h34.1m +34° 57' 46° M -0.4
03-08 22h06.8m +38° 40' 46° M -0.6

46P/ Wirtanen
Date (00 UT) R.A. (2000) Dec El Sky Mag
02-06 00h18.7m -04° 13' 46° E 11.1
02-11 00h34.0m -01° 54' 45° E 10.9
02-16 00h49.8m +00° 29' 44° E 10.7
02-21 01h06.2m +02° 56' 44° E 10.6
02-26 01h23.2m +05° 27' 44° E 10.5
03-03 01h40.9m +07° 59' 44° E 10.4
03-08 01h59.2m +10° 32' 44° E 10.4

81P/ Wild 2
Date (00 UT) R.A. (2000) Dec El Sky Mag
02-06 07h54.3m +19° 49' 159° E 10.5
02-11 07h51.1m +20° 16' 154° E 10.4
02-16 07h48.5m +20° 40' 148° E 10.4
02-21 07h47.0m +21° 02' 142° E 10.3
02-26 07h46.5m +21° 21' 137° E 10.2
03-03 07h47.1m +21° 37' 132° E 10.2
03-08 07h49.0m +21° 49' 128° E 10.2

Comet Hale-Bopp continues to brighten in the morning sky. It is an easy unaided-eye object for early risers. You might want to start planning now on holding public star parties to show Comet Hale-Bopp. In February and early March the comet is visible in the morning eastern sky. Go ahead, schedule a morning star party! As March progresses the comet is better visible in the evening western sky. On the evening of Sunday March 23 a partial lunar occurs for the US, and Saturday April 12 is Astronomy Day. These nights, and those in-between, are good ones on which to show the comet. Then, from after Full Moon (Apri l 22) until the comet moves too far south to be easily visible (the first week of May), you'll have your last opportunities to show Comet Hale-Bopp.

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 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

An Observer's Guide to Comet Hale-Bopp by Don Machholz
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DO WE REALLY NEED MORE PRISONS? (or, Welcome to Fremont Peak: "Light Pollution City?")

By Robert S. Hoyle

(Editor's note: TVS member Robert S. Hoyle provided this article in order to alert amateur astronomers to the growing problem of light pollution in Northern California.)

Well, do we need more prisons? I'm not sure, but I'll bet that most astronomy-types at least think about this when they see the light pollution coming from the ones at Soledad, and its effect on Fremont Peak. A single prison has been there for several years, but its light pollution was fairly moderate. Now, however, a completely new pris on with extremely bright lighting has been added. This and the apparent upgrading of the old prison's lighting make the light pollution from this combined facility overwhelming.

I first noticed this one night last April when I was setting up to do astrophotography at Fremont Peak, some 22 miles north of the prisons. I looked to the south that night and thought, "What's San Jose doing down there?". The intensely bright sky glow from the prison complex was clearly visible even 22 miles away. Photographically the true impact could be seen piercing up into the dark sky a full 35 degrees. Alas, the only remaining part of the sky that was truly dark at Fremont Peak had been dealt a crippling blow. Now, large aperture scopes looking for faint objects to the south may be operating at an "effective aperture" as low as 23 to 39% of their capacity; and any film photography seeking faint detail will likely be "sky-fogged." I was stunned.

Sure, I was aware of light pollution at the Peak and how it has been getting progressively worse in the last 10 years or so. But before the Soledad problem, the southern horizon at Fremont Peak - with its glorious collection of Milky Way objects - was still remarkably dark, especially when the fog came in covering the valleys. Setting up in this darkness, out in front of the Observatory on the hill overlooking the valley viewing south, and watching the Milky Way rise over the fog, was just a little awesome - something beyond words, perhaps. Yes, I was stunned to have lost this - along with the best views of some of the most beautiful objects in the heavens - like M8, M16, M17, M20, M24, Omega Centauri, M83, NGC253, Centaurus A, the Helix Nebula, etc.

But that's not all. As we lose the skies at Fremont Peak, we effectively forfeit all of the wonderful facilities and conveniences there, too. What a shame. Still, this is how it seems to go with light pollution and astronomers. We think "you can't stop progress; sky glow is just the price we pay for living in a civi lized world." When the inevitable growth comes, with all its attendant lighting, we pack up and move all of our equipment, and our hopes, farther and farther away to get to dark skies. We just give up all the wonderful things about a place like Fremont Peak. But we've got to start drawing a line here, somewhere - we're backing ourselves into a corner! We can't just keep sticking our collective heads in the stars (sand?). Truly dark-sky sites that have any degree of accessibi lity and convenience, are becoming almost impossible to find today. Think what it's going to be like in another 10 years if light pollution continues to grow as it has in the past.

It doesn't have to be this way, though. The International Dark-Sky Association (IDA), a nonprofit corporation with a broad range of membership in different fields from 63 countries, is doing everything it can to help diminish excessive sky lighting. They take a common-sense, cooperative approach in working with the people at light pollution sources to illustrate how required lighting can be maintained while saving money at the same time. By using levels of lighting brightness that truly fit the situation, and fixtures that direct the light downward to the ground, not up, everyone wins.

Maybe we should look at the Soledad Prison light pollution problem using the IDA approach. For starters some questions might be: Just how much outdoor night lighting do they need at a prison and how bright should it be? ( Aren't the pris oners locked up inside all night anyway?) If pris on officials are mostly concerned about escape attempts, couldn't they use motion sensors to flood the area with lights if someone is detected - not just run them all night at full wattage? There are many other questions. Can you think of a few? And now may be the time to raise these issues as publicity is being focused on the current Federal and State investigations of the Department of Corrections (DOC). Amongst other things, these investigations seek to determine if "staged" inmate violence has been used to justify excessive demands for facility budgets. In all likelihood the DOC people are just well-intentioned public servants trying to do a difficult job. But maybe they have been so awash in money that they really didn't think about energy-efficient lighting.

These kinds of problems for astronomers are not going to go away on their own; there will be other light pollution issues for us in the future and maybe more "Soledads" - you can bet on it. (The DOC wants to build five new prisons in the coming year; 15 in the next five years.) Sometimes these things creep up on us slowly like ice freezing on a pond; before you know it, the sky is awash in thousands of overly-bright, unshielded street lights. In other instances they hit us like a car wreck: "That'll never happen to me" - then WHAM! - a Soledad Prison. Or maybe a "Garlic World." Garlic World U.S.A. , to be built in Gilroy just north of Fremont Peak, is a $500 million, 200-acre theme park (twice the size of Disneyland) modeled after the hugely popular Branson, MO country music facility, and will include dining, shopping, and 12 live music theaters.

Don't be frozen out of the night sky; don't be WHAMMED! You'd never think of letting your children be deprived of experiencing the beauty and wonders of Nature - things like butterflies, birds, forests, and the oceans. But that is exactly what is happening to them with light pollution. They are being systematically excluded from the wonderful experiences of a truly dark sky, where their spirits and imaginations can soar amongst the stars of the Milky Way.

So it's obvious then: like air and water pollution, light pollution is an "environmental issue" - only, as the IDA says, "it won't rot your lungs, it only erodes your soul." The IDA also makes some other eloquent points: "Our place in the universe is defined by the light from these stars and galaxies; they give us a sense of whom and what we are. And to reach us with these lessons, this light often travels for hundreds, thousands and even billions of years - what a shame to lose it to light pollution on the last moments of its long journey." And from the IDA, quoting Margaret Mead the famous anthropologist: "Never doubt that a small group of

thought ful, committed citizens can change the world. Indeed, it is the only thing that ever has."


1. Let your club officers know that you support their involvement in addressing this Soledad Prison lighting problem and in working with other astronomy organizations to define a unified, coordinated effort in talks with State and pris on officials.

2. Ask your organization to join the IDA; you join the IDA. Amazingly, there are only about 1800 members worldwide - that's less than 2% of the amat eur and professional astronomers out there! The IDA really needs our support. Individual membership is $20/ yr.; an organizational is $100 /yr: The IDA, 3545 N. Stewart Ave., Tucson, AZ 857 16 (WWW :

3. If you have resources that might help in resolving the Soledad problem let your club officers know - e.g., contacts or information concerning government officials, lighting engineers, and people in other organizations favorable to our cause.

4. Be on the alert for future light pollution problems. The best time to solve a light pollution problem is before it becomes one. Let your club officers know.

5. Become an advocate for dark skies. A great opportunity exists in the upcoming Comet Hale-Bopp event. Get people to go to a dark sky location to view this comet. Many people were unimpressed with the magnificence of Hyakutake because they only saw it from the cities. Hale-Bopp is another great chance to "show off" dark skies.

In closing, I'll comment that we amateur astronomers often use the express ion "Clear Skies" to sign-off. But if they're not dark, clear doesn't really do much good. Let's make it "Clear and Dark Skies" - to you all.


Linda J. Clark, Warden Soledad State Correctional Facility P.O. Box 686 Soledad, CA 9396 0

Gary Lindsey, Warden Salinas Valley State Prison P.O. Box 1020 Soledad, CA 9396 0

Tri-Valley Stargazers Membership/Renewal Application
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