Prime Focus

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

TVS presents

What: Summer Barbecue Where:

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


August 14, 1998
Dinner, 7:00 PM Scop es, 8:00 PM

Who: You and your family

You, your guests, and the ATMs


TVS presents
Club news and notes
What's Up
Comet Comments
Wonderful web sites
Membership/app lication

TVS needs you, or at least your barbecue gri ll and cooking ski lls, for the annual summer barbecue. This is your chanc e to show off your great grilling technique and accept the adulation of your fellow club members at the same time. TVS will provide charcoal and lighter flui d if you can bring your cooking kettle. Contact President Dave Anderson at

The club will provide various grilled treats, including vegetarian offerings, all the condiments and burger toppings, soft drinks, ice, paper goods, and cutlery. The rest of this feast will be provided by members, according to the chart below. Find the first letter of your last name to discover what you should bring. Prepare or purchase enough to feed eight hungry Stargazers.

A - D Appetizers
E - J Green or frui t salad
K - P Maca roni or potato salad
Q - Z Dessert

After dinner, Rich Combs will present the latest

You ng stars ring the core of NGC 4314, a barred- spiral galaxy. NGC 4314 is 40 million light -years away from Earth in the cons tellatio n Com a Bereni ces. The stellar ring, with a radius of 1,000 light -years, is an exc ellent laboratory for stu dying star formatio n in galaxies. Stars in the spiral arms are less than 200 mi llion years old, while thos e in the ring are cons iderably older. (University of Texas, Yale University, University of Colorado, NASA, and the Hubble Space Telescope Ast romet ry Scie nce Team, June 1998.)

The best in boo ks (Editor's note: this book review introduc es a spo radic feature to be incl uded as spac e and your interest all ow. Other avid users of star atlases have been asked to pro vide their opini ons on the Millennium
Star Atla s. Contact us at circl to
request specific reviews.)

by Dave Sworin During the winter, I borrowed the Millenniu m Star
from the Tri-Valley Star Gazers club library with
a $50 deposit check that was returned when I took these precious volumes back undamaged. I had


Summer barbecue

graduates of the ATM workshop, and their wonderful handmade scopes. Although many of these instruments saw first light at the Sky Shack open house, you can be among the first observers to look through them.

Congratulations to Rich and all the graduates of his latest workshop. TVS also thanks the Nunes Family for their continued generosity in hosting the ATMs. We greatly appreciate all that Rich and the Nunes clan do to keep our telescope-making program such an active one.

Meet the new members at the barbecue

TVS enjoyed a summer growth spurt last month, with six new memberships added to our roster. At the barbecue, please help welcome: Mark Nowell, Richard Sarrica, James Jonske, Dennis Santos, Mitchell Bunnell, and the family of Eugene Para and Christi e Walton.

Club treasurer Gene Nassar undertook the Herculean task of auditing our books and the membership count. Counting each family membership as only two

persons, brings our 1998 year-to- date membership total to 197. Because we do not track kids within a family membership, we don't know precisely how many young people are also members.

The board wishes to thank Debbie Scherrer for upgrading her membership to Patron status. A few more Patronage opportunities still exist for interested and dedicated Stargazers who have been TVS Members in Good Standing for one year or more. Contact observatory director Chuck Grant (e-mail below) if you are interested.

More abo ut our money
TVS thanks Eugene Para and Christi e Walt on for their special donation made at the time they joined TVS. Such tax- deductible gifts to the club are always appreciated and welcome.

At the planning meeting, Gene Nassar reported the following fi scal fitness items.

Checking: $2,611.79
CD#1 $3,301.20
CD#2 $2,558.50
CD#3 $2,023.53

President Dave Anderson 510 /661-4249 Vice President Chuck Grant (925) 449-1500 Secretary Vacant position see Club News 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 94551
Membership: 197

Phil Waide, our school star party coordinator, put his program on hiatus for the summer. Interested members planning ahead for the Fall should contact Phil at (925) 455-6039.

Public star parties are arranged by Jim McIntire, who announces the following events:

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.

Other star parties August 22,
Fremont Peak Star-
B -Que. See page 6 for more details.
August 22,
Mount Tamalpais
Park public astronomy program, "Atmospheric Optics" by Joe Jordan.
August 20 -23,
The Oregon Star
Party. See page 6 for more details.

Club News and Notes Star Parties

2 Sun Europa eclipsed 12:53 AMUra nus at opposition (mag. 5.7, 3.7" diam.). Asteroid 29 Amphitrite (mag. 9.3)
at opposition. 3 Mon Ganymede shadow transit begins 12:35 AMEuropa shadow transit ends 10:47 PM, transit ends
12:47 AM (4th). 5 Wed Venus 0.8° south of Mars. Io shadow transit begins 2:34 AM, transit begins 3:33 AM Callisto shad ow
transit 11:43 PM to 2:37 AM (6th). Io eclipsed 11:54 PM to 3:06 AM (6th). 6 Thu Planet-B launch scheduled (Japanese Mars orbiter). Io shadow transit ends 11:18 PM, transit
ends 12:13 AM (7th). 7 Fri Full Moon 7:10 PM PDT. Penumbral lunar eclipse (penumbral mag. 0.14 9, undetect able to the eye)
ends at 8:19 PM, shortly after moonrise. 9 Sun Europa eclipsed 3:29 AM
10 Mon Jupiter 0.9° north of Moon (occulted in Antarct ic). Europa shadow transit 10:39 PM to 1:22 AM,
transit 12:25 AM to 3:02 AM (11th). 11 Tue Delta Cephei at maximum 12:12 AM Variable rises to mag. 3.5 from 4.4 in about 1.5 days.
(Peri od is 5.366 341 days). Compare Zeta Cephei (mag. 3.35) and Epsilon Cephei (mag. 4.2). 12 Wed Perseid meteor shower peaks about 5 PM (Moonrise about 10:15 PM)
13 Thu Io eclipsed 1:48 AMSatu rn 2° north of Moon.Ganymede eclipse ends 9:49 PM, occulted 9:53 PM to
12:55 AM Io shadow transit 10:57 PM to 1:12 AM, transit 11:45 PM to 1:59 AM (14 th). 14 Fri Tri-Valley Stargazers meeting 7:30 PM Unitarian Universalist Church of Livermore, 1893 N. Vasco R oad,
Livermore. (3/4 mile north of I-580). Last Quarter Moon 12:48 PM Io ooccultation ends 11:18 PM 15 Sat Star party at Sycamore Grove Park (Livermore Park District) 8:00 PM
(Wetmore Rd. entrance near Holmes St.). 16 Sun Aldebaran 0.2° south of Moon (occulted in Africa, Asia).
18 Tue Europa shadow transit 1:15 to 3:58 AM, transit begins 2:43 AM
19 Wed Europa ooccultation ends 11:28 PM
20 Thu Io eclipsed 3:43 AMVenus 3° north of Moon. TVS Planning Meeting 7:00 PM Round Table Pizza,
154 0 First St., Livermore (in Orchard Supply/Longs/Safeway shopping center). Ganymede eclipsed 10:30 PM, occultation ends 4:18 AM (21 st). 21 Fri Io shadow transit 12:51 to 3:06 AM, transit 1:31 to 3:44 AMSta r Party at Camp Shelly,
Lake Tahoe.New Moon 7:03 PM Annular eclipse in southeast Asia. Excellent weekend for observing. Io eclipsed 10:11 PM, occultation ends 1:03 AM (22 nd). 22 Sat Star Party at Camp Shelly, Lake Tahoe.Io shadow transit ends 9:35 PM, transit ends 10:10 PM
25 Tue Io shadow transit begins 3:51 AMMerc ury 3° south of Venus in morning twilight.
26 Wed Europa eclipsed 10:01 PM, ooccultation ends 1:45 AM (27 th).
27 Thu Delta Cephei at maximum 2:34 AM Space Shuttle Columbia (STS-93) launch scheduled.
28 Fri Ganymede eclipse begins 2:32 AM Io shadow transit begins 2:46 AM, transit begins 3:15 AM
29 Sat Io eclipsed 12:05 AM, ooccultation ends 2:47 AM Io shadow transit 9:14 to 11:30 PM, transit 9:4 1
to 11:55 PM First Quarter Moon 10:06 PM 31 Mon Mercury at greatest western elongation (18 ° ) in morning sky. Ganymede transit ends 9:23 PM

What's Up in August Dave Anderson

C/1997 J2 (Meuni er-Dupouy)
08-05 21h51.3m +18° 10' 143 ° M 11.3
08-10 21h45.6m +16° 21' 147 ° M 11.3
08-15 21h39.8m +14° 26' 151 ° M 11.3
08-20 21h34.1m +12° 25' 154 ° M 11.4
08-25 21h28.7m +10° 21' 156 ° M 11.4
08-30 21h23.5m +08° 16' 156 ° E 11.4

C/1995 O1 (Hale-Bopp)

Date (00UT)R.A. (2000)DecElSkyMag
C/1995 O1 (Hale-Bopp) (cont.)
Date (00UT)R.A. (2000)DecElSkyMag
08-05 06h54.4m -54° 10' 76° M 10.8
08-10 06h58.7m -54° 49' 77° M 10.8
08-15 07h02.8m -55° 30' 77° M 10.9
C/199 8 M5 (Linear)
Date (00UT)R.A. (2000)DecElSkyMag
08-20 07h06.7m -56° 14' 77° M 10.9
08-25 07h10.5m -56° 59' 78° M 11.0
08-30 07h13.9m -57° 46' 78° M 11.0
08-05 22h30.1m +30° 34' 128 ° M 11.8
08-10 22h19.9m +32° 19' 130 ° M 11.6
08-15 22h08.4m +33° 57' 131 ° M 11.5
08-20 21h55.8m +35° 27' 132 ° E 11.4
08-25 21h42.3m +36° 46' 132 ° E 11.3
08-30 21h28.0m +37° 53' 131 ° E 11.3

The Lincoln Laboratory Near- Earth Asteroid Research Project has found four more comets. One of them, C/1998 M 5 (Linear), should be visible in our northern skies for the next year. Meanwhile, two more faint comets have been discovered by the Spacewat ch program at Kitt Peak, one being visually found on an image-di splay monitor by J Montani.

The SOHO satellite found nine more comets, most being sungrazers. All disappeared into the solar vicinity. In late June, contact with the SOHO spacecraft was lost during a positioning maneuv er. Hope is not lost, technicians are still working on it. "Comet Comment s" celebrates its 20th year with this, its 240th column. It all began in August 1978 when I wrote my first regular comet article for the San Jose (California) Astronomical Association Newsletter. At the same time I

also wrote an article suggesting a star party in March to find the Messier Objects-our first Messier Marathon. It was only a few weeks later on, Sept. 12, 1978, that I discovered my first comet.

COMET HUNTING NOTES: The Edgar Wilson Award has been announce d for amateurs who discover comets. A cash award of about $20,00 0 will be dis tributed each June 12th among those finding comets during the previous year. The rules are few. The comet must be named after you and you must be using your own equipment in an amateur capacity. The discovery may be made by visual, photographic, or electronic means. The amount an individual receives depends upon the number of comet finds during the year. For example, in the past twenty years, an individual would have received between $1,500 and $20,000 for a comet find.

Ephemerides Orbital Elements

Object: Hale-Bopp Meunier-Dupouy Linear
Peri. Date : 1997 04 01.13 47 1998 03 10.43 65 1999 01 24.00
Peri. Dist (AU): 0.91 4008 AU 3.05 1015 AU 2.11 102 AU
Arg/Peri (2000): 130.5787 deg. 122.6755 deg. 089.452 deg.
Asc. Node (2000): 282.4653 deg. 148.8429 deg. 333.261 deg.
Incl (2000): 089.4268 deg. 091.2731 deg. 080.342 deg.
Eccen: 0.99 5085 1.00 0760 1.0
Orbital Period: ~250 0 years Long Period Long Period ?
Ref: MPC 3073 8 MPC 3073 8 IAUC 6961
Epoch: 1997 12 18 1998 03 08 1999 01 24
Absol. Mag/"n": -1.0/4.0 4.0/ 4.0 5.5/ 4.0

Comet Comments Don Mac hhol z

wondered whether I would buy this atlas for myself or not. I am still not sure and I thought I would share my thoughts with the club. Since I already own both Ura nometria
volumes, I thought I could best evaluate the Mill ennium Star
by comparing it with Ura nometria . Please read the
opi nions that follow with a grain of salt.

Easier to navigate across the sky in an arm chair with the Millenniu m Star Atlas than with Ura nometria because as the
pages increase, the Right Ascension decreases (just as when you face South the Right Ascension decreases as your view goes across the sky from left to ri ght).

The arrangement of the charts by Right Ascension so that each volume covers 8 hours of the sky leads to less obtrusive cutoffs at the edge of a volume. Even with the generous 12 degrees of overlap provided by Ura nometria between volume
I and volume II, the frustration of exploring the Orion region which gets spli t between the volumes sti ll an annoying memory. Since the sky shifts during the seasons and during the night by Right Ascension, this layout of the chart more naturally puts the right volume in your hand at the right time, than Ura nometria does, when at any given
time you might need two volumes.

It shows more stars, about three times the number shown in Ura nometria . In some cases these additional stars will
help in star-hopping and locating objects.

It shows many more special stars than Uran ometria . In an
area which I am familar, variable stars, it shows more variable stars with more accurat e locations and additional information, which helps you know the type and range of the variable. While speciali zed star atlases, such as the AAVSO
Variable Star Atlas
by Charles Scovil still have additional
information cartering to the variable star observer, the need for such specialized star atlases is lessened with the release the Mill ennium Star Atlas .

Disadvantag es
Cost. The price of over $225 versus Uranometria's $80 for two volumes is a big jump, more than the increase in value in my opini on. When I went from the Sky Atlas 2000.0 to Uranometria with a jump from $25 to $80, also a factor of about three, I felt I got my money's worth for the extra outlay. I do not have such a feeling about the Millenni um
Star Atlas
. Some of the dis advant ages given below may help
explain this feeling.

For three times the price there is not much improvement in star-hopping abili ty with the Millenn ium
Star Atlas
over Ur anometria . This is because the big
Dobsonian telescopes, 8 or more inches in diameter can see to magnitude 14 or fainter under a dark sky and the magnitude 11.5 limit of the Millenniu m Star Atlas still is
not anywhere near the visi bili ty limit for these telescopes.

The volumes are too big and bulky for easy field use without a table and chair setup at a dark sky site.

Each page covers such a small region of the sky that many of the pages do not have any object, stellar or otherwise, which an advanced amateur would readily recognize and thus know how this page in the atlas related to the sky.

Each of the Milleni um Star Atlas volume is large and
heavy. The larger and heavier a reference is the more work it is to use it. The extra work is negligibleon an absolute scale, but as generations of teachers repeating "look it up in the dictionary" over and over demonstrate the human desire for convenience is overpowering. Uran ometria is
much more convenient. Its volumes are larger than 8 1/2 by 11 inches but still reasonable, whereas the Millenni um
Star Atlas
volumes are more like an unabridged dictionary.

For an atlas this large, the Millenniu m Star Atlas has a
rather limited selection of deep sky objects. The 10,00 0 or so objects is plenty for most any observer, but less, not more, than other comparable star atlases such as Ura nometria or the Heral d-Bobroff AstroAtlas . What are
all those additional stars for if not to give a better context to many more and fainter non-stellar objects?

If you have a big table and you like to look over a sky atlas as you prepare for your observing or doing research, I think the Millenniu m Star Atlas makes a superb desk
reference. With a nice large work area and the comfort of

Remember, you can use the club copy of the Mi lle nniu m Star Atl as,
and jud ge for yourself. See librarian
Chris Cody at the barbecue or next general meetin g.

The best in boo ks

indoors, the large size of the volumes would not be a problem and the wealth of information supplemented with an much smaller atlas such as the Cambridge Star Atlas
or Norton's Star Atlas would make for a pleasureable and
rich investigation of the sky, right in your home. Clearly the Millenn ium Star Atlas makes a better desk reference
than Ur anometria , with the exception that it does not yet
have a field guide with deep sky data in it. It does, however have more information about the objects encoded in symbols and labels right on the charts which is more convenient.

If you observe from your back yard, the size of the volumes is also not as much of a problem and having a table along for these hefty volumes is no problem. I think I would get the Millenium Star Atlas instead of
Ura nometria if I were mostly oberving from my backyard.
The extra stars are more important in a light-polluted sky since the constellat ions are more difficult to di stinquish and parts of the constellations may be blocked by nearby buildings and trees. Having more stars in the field of view to nail down your exact location would be a big help.

For dark sky-star hopping, I do not see much advantage in the Mill ennium Star Atlas . Ur anometria has enough to
get the job done and it is less bulky and less of a hassle in field. You can set Ura nometria down almost anywhere,
not requiring such a sturdy table. It is more portable: small and lighter and less volumes. I recommend Ura nometria for deep sky observing away from home. The
Mill ennium Star Atlas is overkill for star hopping and too
much more of a nuisance to transport and manipulate in
the dark.

If you are a deep sky fanatic, then I cannot recommend Mill ennium Star Atlas . The best overall atlas just for deep
sky observing which I have seen is the Herald-Bobroff
from Orion dis tributed by Crazy Ed Optical
here in the United States. In fact, Sky and Telescope
seems to pretty much imi tate the way the Heral d-Bobroff
encoded lots of information on the charts so
you did not have to have a reference volume with you all the time. In addtion, the Herald-Bo broff AstroAtlas has
many more deep sky objects.

Wonderful web sites (Editor's note: This colum n introduces ano ther feature that will be run in Prime Focus on a regular basis, reader interest
permi tting. You are invited to send your favorite sites to the editor by the 10th of the month.) http://www.psi m alpo/jup.html tra/similar/ catalogs.html

The best in boo ks Vote at the barb ecue!

The long-awaited club vote on a new name for our dark sky site and observing hill will occur just after dinner at the barbecue on August 14. Each Member in Good Standing is entitled to one vote on the new Sky Shack moniker. Even if you cannot join us for supper, please come at 7:45 PM to cast your vote.

A short list of eligiblenames will be presented by Dave Anderson. Please remember that the name selected cannot reveal the location of the site.

Star parti es

Fremont Peak State Park offers viewing through its 30-inch Challenger Telescope during the Star-B- Que set for August 22, from 4 PM on. Plan to bring a desert, salad, or sidedish to share. FPOA will provide burgers and fixings. Call FPOA at 408 /623-2465, by August 19. Leave your name, number of guests, and tell them you are a TVS member. Cost is $3 per car, transient, or $7 per car for an overnight stay. Use the park-provided payment envelopes.

The Oregon Star Party will sponsor its 11th annual renewal from August 22-23, at Indi an Trail Spring in the Ochoco National Forest, northeast of Bend and Prinevi lle. Viewing includes a solar scope fi tted with H-alpha filter and a brilli ant Milky Way. Costs are $30 for adults, $15 for ages 13-17, $5 for ages 6-12, and younger children are free. Lat e fees apply for reservations made after August 11. Point your browser to

What's up in August


Mercury Inferior conjunction at mid-month. Low in east before sunrise late in month. Venus Very low in east-northeast before sunris e.
Mars Very low in east-northeast before sunris e.
Jupiter Rises in early evening; up nearly all night.
Satu rn Rises in late evening; south in morning sky.
Uranus At opposition; up all night.
Neptune Up nearly all night. Pluto Southwest in evening sky; sets about midnight.

Messier and Caldwell objects

Cep C12 (galaxy)
Cyg M29 (open cluster), C15 (Bli nking Neb.),
C20 (North America Neb.), C27 (Crescent Neb.), C33 & C34 (Veil Neb.) Lyr M56 (globular cluster)
Vul M27 (Dumbbell Neb.), C37 (open cluster)
Sge M71 (globular cluster)
Del C47 (globular cluster)
Aq r M72 (globular cluster), M73 (4 stars)
Sgr M55, M75 (globular cluster), C57 (Barnard's Galaxy)
CrA C68 (R CrA Neb.)

The board approved $100 to pay the club's annual renewal as a member of the International Dark Sky Associati on. IDSA works to preserve dark skies nationwide, working with local agencies to reduce light pollution.

After a brief discussion, the board elected not to contribute to this year's Yosemite Fund drive. In the past, the club and individual members have been strong contributors. This year, our donation would not be earmarked for specific use at Glacier Point, the site of our annual Yosemite Star Party. The board will annually study the proposed dis tribution of the Yosemite Fund and will partici pate when public astronomy benefits.

Happenings on the observing hill
We have a problem with the lock on the front gate! Some mis creant has repeatedly left the lock with the combination dialed on it. The apparent result is that non-members have learned the combination and now access the site without our permission. The property owners have requested a new combination lock for the front gate. If it is in fact necessary to replace the lock, authorized TVS key holders will be notified individually of the new combination. In the meantime, do not neglect the lock. Reset the combination dial every time you access the site.

On a happier note, recent observing session reports indicate that the summer season is a particularly nice one this year at the Sky Shack.

Work on the new mount is progressing well. An aluminum cradle is being fabri cate d per Mike Rushford's design. Chuck Grant will obtain a 7.5-inch Beyers gear and worm mount, at a price not to exceed $128, including delivery charges. The club particularly thanks Debbie Dyke for her donation of a copy of the manual and literature for the controller. We appreciate her interest in this project.

Thank you, Mr. and Mrs. Anonymous!
One of our particularly dedicated Family Member couples made a unique donation to TVS during July. The board was considering possible uses of a di gital camera for photographs in Prime Focus and on our website. Upon
hearing this discussion, Mr. and Mrs. Anonymous offered the club their digital camera, a Kodak DC 10. The board imedi ately accepted this generous donation. We will use the camera to explore the many ways that digital photographs might be incorporated into TVS programs, presentations, and publications.

We thank the donors for this unusual gift that allows us to learn about and experiment with digital photography without spending club funds to do so. If the digital camera proves to be a useful club tool, the board will price newer models with the special features and advantages that sui t our particular needs.

At the August barbecue, collar any board member if you would like to see speci fic photographs posted to the website or printed in Prime Focus .

Club News and Notes

Prime Focus Tri-Valley Stargazers Newsletter P.O. Box 2476 Livermore, CA 94551

Tri-Valley Stargazers Membership 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________ __________ ______

Address_______________ ____________ ____________ ____________ ____________ ____________ ____________ ______ _______
__________N otif y me by e-mail when Prime Focus is available on the Web.____ _______Do not mail Prime Focus to me.

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
_________ _$20 Sky Shack refundable key deposit (key property of Tri-Valley Stargazers)

$__________Tax-deductible contribution to Tri-Valley Stargazers $__________TOTAL Return to: Tri-Valley Stargazers. P.O. Box 2476 Livermore, CA 94551. 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 ]%%

Date (00UT)R.A. (2000)DecElSkyMag