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
Atlas
by comparing it with
Ura nometria
.
Please read the
opi nions that follow with a grain of salt.
Advantages
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?
Conclusions
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
AstroAtlas
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
AstroAtlas
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.c2i2.com/~medkeff/newsletter.html http://www.psi az.com/sac/home.ht m http://www.lpl.arizona.edu/~rhill/ alpo/jup.html http://www.used-telescopes.com http://www.astromart.com http://members.aol.com/nitelites/ http://www.rahul.net/resource/TAC http://www.seds.lpl.ari zona.edu/messier/x 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 http://www.teleport.com/~ospinc.
What's up in August
Planets
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.
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