Home Back to screen-friendly "Monthly Sky"
Full Moon:
Dec 8
New Moon:
Dec 23
STAR GAZE (Dec 19):
Sun: Sets at 5:22pm, astronomical twilight ends at 6:50pm
and begins at 6:04 the next morning. Sun rises on Dec 20 at 7:35am.
Moon: (illuminated 14%) The thin crescent Moon rises at 4:19am. We get
about 8.5 hours of darkness from the end of astronomical twilight until the
moon rises.
Jupiter & it's moons: Jupiter rises at 11:37pm. Io's shadow
is in transit 12:11am to 02:21am, followed by Io itself from 1:21am to 3:33am.
The latter part of these transits will appear clearer because Jupiter will be
higher in the sky at that time. You need only about a 6"
reflector to see transits! Begin to look for a Jovian moon in transit
about 30 minutes before it leaves Jupiter's disk, or just as begins to cross
in front of Jupiter's disk. Once the moon gets more towards the middle of Jupiter's
disk, the tiny, sharp, white disk of the moon is much more difficult to detect.
In contrast to this, the shadow of the moon is visible all the way across Jupiter's
disk. This is because of the greater contrast between the dark shadow and the
bright disk of Jupiter. The Great Red Spot will be on Jupiter's meridian
as Io's transit begins, and will be visible until about 1:30am, when it begins
to slip around the west side of the planet.
Saturn: Rises at 8:08pm. It culminates (highest
in the sky) at 1:23am, so the view is good from about 11:00pm to about 4:30am,
when Saturn is higher than 45 degrees above the horizon.
Asteroids: Ceres (in Gemini) rises at 6:45pm
on the night of the gaze. It culminates at 2:20pm. You can see it in binoculars
as a star-like object at magnitude 7.2.
PLANETS:
Mercury: Find it low in the west,
early in the month. Magnitude 0.0, 7.8" (arc seconds) diameter on December
7th. Mercury will be at greatest elongation on Dec 9.
Venus: Low in the south west after
sun set. Magnitude -4.0(!), 12" diameter on December 7th. By month's end,
Venus sets 2.5 hours after the sun, and is 23 degrees above the horizon at sunset.
Mars: High in the south at sunset. Magnitude 0.0.
Closest approach to Earth was on August 27th at 26" diameter. It's diameter
is 11" on Dec 1, and decreases to 8.5" on Dec 30..
Saturn: Rises at 7:33pm on Dec 1, at 5:21pm on Dec
31. By month's end it culminates at 12:35am. Magnitude 0.4, 20" diameter.
Saturn is at opposition on December 31, so it's a great time to view the planet.
Jupiter: Rises at 12:46am on Dec 1, at 10:56
pm on Dec 31. Culminates about sunrise. Magnitude -2.1, 38" diameter.
Uranus: At magnitude 5.8 it can be seen without optical aid from a dark site. Culminates (highest in the sky) at about 6:00pm during the middle of the month, so catch it early in the night.
Neptune: At magnitude 8.0 it can be seen
with binoculars. Culminates before dark during the middle of the month,
and sets at 9:00pm, so catch it early in the night.
Comet P2 Encke: Closest to Earth (0.26 AU) in mid-November,
it's brightness was about 7.0 in late November. It will appear closer and closer
to the sun and may be unobservable by early December as it moves south &
west into Ophiuchus. It's orbit takes only 3.3 years, but this is it's closest
approach for Northern Hemisphere viewers since 1838. See Sky
& Telescope article and MISAO
map.
DEEP SKY OBJECTS (DSO's)
(Not the biggest or brightest, but interesting):
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)
Double Stars:
An in-depth Double Star article, centered around Pegasus: www.cloudynights.com/Observation/doubles.htm
Be sure to find Iota Tranguli & Gama Andromedae (or "Almaak").
Both are beautiful yellow-blue pairs.
HIGHLIGHTS:
Dec 2: Chi Orionid, a minor meteor shower with a Zenithal Hourly Rate (ZHR) of only 3. These meteors tend to be slow and faint, but the moon sets just after midnight, so this is as good a time as any to see them.
Dec 8: Earliest sunset at 5:19pm.
Night of Dec 13-14: Geminid Meteor Shower, the moon will interfere. Sky & Telescope Article
Dec 19: The Roman holiday Saturnalia, linked to the end of the harvest season and the rebirth of the sun.
Dec 22: Winter solstice.
Dec 29: Comet P2 Encke is at perihelion (closest to the sun).
CLUB STARGAZE:
You can check the Yahoo group for
AstroAsheville (or call Tim @ 251-0040
or John @ 251-1933 x17 (before 5:00) or 667-9268 (after 5:00)) for a go/no-go
decision and to verify location.
CLUB MEETING:
The club meeting is the first Thursday of every month, at
6 p.m. at Sim’s
Group located at 230 Short Coxe Ave., Asheville, NC.
Happy Starwatching! Dress Warm!
Blue Ridge Parkway Information
Line is 828-298-0398
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THE BIG PICTURE: Each chart below covers a very wide area of sky, roughly from eastern horizon to western horizon. Constellations are green stick figures. The dividing line between constellations are dashed blue lines. The purpose is to show the large scale structure of the night sky: why certain types of objects are visible in certain areas of the sky.
1. Above: 6 hr
R.A. (passes overhead on winter evenings,as in December): OPEN CLUSTERS
in the sky north to south (Auriga to Pupis). Open Clusters are generally within
the arms of the galaxy and are roughly co-located with the Milky Way. They are
plotted as tan circles above. You are looking away from the center of the galaxy.
(Note: all types of objects are labeled, not just open clusters.)
2. Above: 12
hr R.A. (passes overhead on spring evenings; rises before sunrise in December)
GALAXIES in the sky north to south (Ursa Major to Virgo). They are plotted
as blue ovals in the chart above. At 9:00pm during mid-June, the Milky Way is
rising in the east. Just to the west of the zenith is the North Galactic Pole,
in the constellation Coma Berenices. In southwest Coma Berenices happens to
be the heart of the Local Supercluster of galaxies. Many of these galaxies are
visible in medium-sized telescopes.
3.
Above: 18 hr R.A. (passes overhead on summer evenings; not visible in
December): GLOBULAR CLUSTERS (yellow cross inside a circle) & PLANETARY
NEBULAE (blue circle in a cross) in the sky north to south (Cygnus to Sagittarius).
The lower-middle of this chart is towards the center of the Milky Way galaxy.
Charts created using Megastar
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(Much of the above info derived from Sky & Telescope and Astronomy magazines, Ottewell's Astronomical Calendar, The Night Sky Observer's Guide, Megastar 5.0, Planets202, the ol' Miller Planesphere, and a little (very little) common sense.)