| 17 December 2004
Eye on the Sky
by Paul Curtin
The moon occults Jupiter just before
dawn on December 7. This is fully observable in the
eastern U.S. and Canada, as well as a section of Brazil
and western Africa. See Gupta (1) for details.
Southern observers with dark skies get the first glimpse
of Comet Machholz this month. Look for it west of Lepus
and moving due north throughout the month. For northerners
the end of the month and early 2005 will provide a better
show. (See reference 2 for finder charts and orbital
information.)
December in the north means a return
to bright stars and easily recognizable asterisms. The
first sight of the Pleiades in the east announces the
end of Autumn darkness.
Our northernmost constellation this
month is Camelopardalis, an indistinct group of rather
faint stars occupying a large area between Cassiopeia
and Ursa Major. Due east of Delta Cassiopeiae is a line
of stars known as “Kemble’s Cascade.”
Very close to NGC 1502, this can be easily viewed with
binoculars. Though it lacks bright stars, there are
some interesting deep sky objects for the intrepid star
hopper in Camelopardalis.
South of this we find Perseus, a constellation
rich in double stars, variable stars and a wide range
of deep sky objects. Perseus somewhat resembles a person
stepping towards the west with an arm flung out to the
east. In the northwest, not far from Cassiopeia, we
find the famous double cluster NGC 869 and 884, a great
object for wide field telescopes and binoculars. Use
binoculars to observe Melotte 20, the extended open
cluster that includes Mirphak (Alpha Persei). Variable
star observers can monitor the eclipsing binary Algol
(Beta Persei) throughout the night. Only in the winter
months is it possible to watch the entire 10-hour eclipse
from start to finish. (See reference 1 for Algol’s
timing).
Beneath Perseus, in the otherwise unremarkable
region of western Taurus, are the Pleiades, delightful
both to the naked eye and in telescopes. Mapping the
young stars of this bright, open cluster is a rewarding
project. Long exposures show the surrounding reflection
nebula so elusive to the eye save in the darkest of
skies. South and west of the Pleiades is the eastern
region of Cetus. Mira (Omicron Ceti) is rebounding from
the faintest stage of its 332-day cycle. Otherwise
Cetus is star poor but galaxy rich as are many constellations
so far from the rich background of the Milky Way. Look
for M77, a face on galaxy near Delta Ceti, north and
east of Mira.
South of Cetus we find Fornax and Eridanus.
Fornax is dim but, especially in its eastern section,
full of galaxies, planetary nebulae and even a globular
cluster (NGC 1049). 1049 is of interest as it belongs
not to the Milky Way but to a sister member of the Local
Group. Eridanus is a river that flows from Orion to
the southern circumpolar region. It is notable mostly
for faint galaxies and its bright Alpha-Achernar, the
end of the river.
Closer to the pole is Hydrus, best
known perhaps as the rather plain sector between the
Small and the Large Magellanic Clouds (of which more
next month...).
Mercury is in Scorpius in the predawn
sky. Look for it in conjunction with Venus on 29 December.
Venus shines brightly in the morning
twilight. It is in conjunction with Mars early on 6
December.
Mars becomes easier to observe this
month, rising before dawn as it moves into Scorpius.
Jupiter can be observed in the morning
sky. It is outshone only by Venus and is very easy to
find.
Saturn, in Gemini, is our lone evening
planet this month. It rises at dusk and can be observed
throughout the night.
1. Gupta, R. (ed.) Observers Handbook
2004. Toronto: University of Toronto Press, 2003.
2. Sky and Telescope 109, 1, 2005.
Burnham, Robert Jr., Burnham's Celestial
Handbook, New York: Dover, 1978.
Kepple, G. R. and Sanner, G. W., The
Night Sky Observers Guide, Richmond, VA: Willman-Bell,
1999.
Tirion, W., Rappaport, B. and Remaklus
W., Uranometria Deep Sky Atlas, Richmond, VA: Willman-Bell,
2000.
Webb, T. W., Celestial Objects for
Common Telescopes, New York: Dover, 1962. 
|
