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New Moon:
Dec
9
Full Moon:
Dec
23
Club Indoor Meeting: Thursday,
Dec 6 (the earliest sunset of the year!)
Club Stargaze: Friday, Dec 7. The sun sets at 5:15pm and
astronomical twilight ends at 6:44pm. You can check for satellite passes by
going to "www.heavens-above.com"
and logging-on as registered user "Astro Asheville" with password
"12345". There are several observing sites to choose from. Choosing
the correct site is important only for seeing the Iridium flares.
There is a mag 0 Iridium flare this night at 5:40 pm, 73 degrees altitude and
52 degrees azimuth (NE).
The Space Station passes over at 6:23pm, very low (maximum altitude 11 degrees),
heading NW to N. It's magnitude will be 0.5.
NOTE: Due to weather, the December star gaze has been postponed until
Friday, December 14.
DEEP SKY OBJECTS (DSO's):
Open
Clusters (The closeness of these two objects is what is special. Their
centers are only 24' apart.) :
NGC 2168 (M35): Mag 5.1, 28'
in size. Visible as a hazy patch to the naked eye. 2,200 light years away. It
is found at the foot of the twin "Castor" (he's the one on the right,
or northwest side), so it's EASY TO FIND. (Location: 6hr 9m RA
+24 deg 20' Dec, in Gemini)
NGC 2158: Mag 8.6, 5' in size. This open cluster is in the same field of view as M35 above, but, at 13,000 light years, is 6 times further away. What a great sense of distance! Thru a small scope it appears as a patch of light with only a few stars resolved. It is so condensed that it resembles a globular cluster. (Location: 6hr 7m RA +24 deg 06' Dec, in Gemini)
Globular Cluster:
M79:
Mag 7.8, 8.7' in size. What makes this object so interesting is it's location
in the sky and where it came from. If you look at The
Big Picture you will see that M79 is the only globular cluster in this part
of the sky. That is because you are looking away from the center of the galaxy,
around which most globulars are arranged in a spherical "halo". M79
seems to be a (former?) member of the Canis
Major Dwarf galaxy, which is being amalgamated into the Milky Way. M79 is
41,000 light years away, much further away than the two open clusters mentioned
above. This globular cluster is located in the constellation Lepus, below Orion.
To find M79 draw an imaginary line from Alpha Leporis through Beta Leporis and
continue it for the same distance. So once you find the constellation Lepus, M79
is EASY TO FIND. (Location: 5hr 24.5m RA -24 deg 33', in
Lepus)
NGC2419 (C25, or The Intergalactic Tramp): Mag 10.3, 4.6' in size (about the same apparent size as open cluster NGC2158 above). This globular cluster is similar to M79 (above) in that it is the only globular cluster in this part of the sky, and it too is on the other side of the sky from the center of the Milky Way. What makes it different is that it is almost 7 times farther away than M79 and is completely beyond what is normally considered "our galaxy". It is 270,000 light years from Earth, 300,000 light years from the galactic center, and is the most distant globular cluster that can be seen thru most amateur telescopes. Don't expect to see individual stars in this cluster because they average only 17.3 magnitude. It was once thought that The Intergalactic Tramp had enough velocity to escape from the Milky Way, but with a better understanding of the true mass and extent of our galaxy, it is now thought that it is quite firmly bound, and that it's other name, "The Intergalactic Wanderer", is not so appropriate. This isn't a visually beautiful object. It's beauty for us lies in a profound sense of distance and of vast space. (Location: 7hr 38.1m RA +38 deg 52.9', in Lynx)
White Dwarf Star:
Wolf 28
(Van Maanen's Star): Mag 12.3. One of the few white dwarf stars visible through
amateur telescopes, it shines only by radiant thermal energy. Nuclear fusion stopped
after the star went through the red giant stage and blew off its outer layers.
It is now very small (about the size of the Earth) and dense. Our sun will go
through this stage also. Wolf 28 is only 13.8 light years away. It is 2.1 degrees
directly south of Delta Piscium, and only 15' NE of a 5.8 magnitude star. You
will need a star chart that goes as faint as magnitude 13, or a star-charting
program on your computer. If you're good at star hopping, it won't be very hard
to find. (Location: 0hr 49.1m RA +05 deg 25' Dec, in Pisces)
Double Stars:
An in-depth Double Star article, centered around Pegasus: http://www.cloudynights.com/item.php?item_id=1136&pr=3x72
Be sure to find Iota Trianguli & Gama Andromedae (or "Almaak").
Both are beautiful yellow-blue pairs.
PLANETS:
Mars: In mid-December Mars rises about 6:00pm at magnitude
-1.6; it's diameter has grown to 16". It will be closer this month than
until 2016. It is much higher in the sky than it was during it's 2003 approach,
so appears smaller but sharper in telescopes. Surface features will be visible
if you are patient.
("Looking
is not observing. So many look but few observe."
This
quote of Richard Baum applies more to planets than to any other astronomical
object. It takes time and patience to see much detail on planets!).
To see Deimos or Phobos you'll probably have to make an "occulting bar"
for one of your eye pieces, and catch the moon when it is most distant from
the planet. See "Mars' Moons" near the bottom of the Sky &
Telescope web site (www.SkyAndTelescope.com) for directions to make an "occulting
bar", and for an interactive Java applet that shows the position of Mars's
two moons thru the end of January 2008.
HIGHLIGHTS:
Dec 7: Earliest sunset of the year at 5:15pm. (Sunset on the evening
of the gaze (Dec 6) is also at 5:15pm, but a few seconds later.)
Night of Dec 13-14: Geminid Meteor Shower with a ZHR of about 120, but North America will see substantially less than that. The radiant, just north of the star Castor, rises about 6:30 pm and the moon sets at 8:57pm, so we will have dark skies for this shower. However the maximum occurs at noon on Friday, so it will probably be best to observe as early Friday night as the moon will let us. Traditionally, Geminids are medium-speed meteors that usually do not leave an afterglow, or train. Most meteors are debris from comets, but Geminid meteors are pieces of the unusual asteroid 3200 Pheathon.
Dec 17: The Roman holiday Saturnalia, linked to the end of the harvest season and the rebirth of the sun.
Dec 22: Winter solstice! The longest night of the year!!
TERMS
AFOV=apparent field of view / dec=declination
/ EP=eye piece / FOV=field of view / ISS=International Space Station / HST=Hubble
Space Telescope / ly=light year / mag=magnitude / ra=right ascension /
culminates=transits the meridian=when an object as at its highest point in the
sky / transit=passing in front of another object / ZHR=zenithal hourly rate (basically,
the most meteors 1 person could see in 1 hour under ideal conditions)
CLUB STARGAZE
You can check the AstroAsheville
Yahoo e-group [or call Tim @ 251-0040 or John @ 251-1933 (before 5:00) or
667-9268 (after 5:00)] for a go/no-go decision and to verify location.
CLUB MEETING
Indoor club meetings are usually the first Thursday of every
month, at 6 p.m. in the Sims
Group offices (230 Short Coxe Ave., Asheville, NC.)
Happy Starwatching! Dress Warmly! Blue Ridge Parkway Information
Line is 828-298-0398
.............................................................................................................................................................................
(Much of the above info is derived from Sky & Telescope magazine, Ottewell's
Astronomical Calendar, The Night Sky Observer's Guide, Burnam's Celestial Handbook,
Megastar 5.0, Planets202, Cartes du Ciel, the ol' Miller Planesphere, and a little
(very little) common sense.)