Post by Chicago Astronomer - Astro Joe on Dec 2, 2006 15:59:59 GMT -6
December 2006 Astronomical Event Calendar
12/2 The Moon is at perigee, subtending 32'39" from a distance of
365,923 kilometers, at 0:00; asteroid 4 Vesta (magnitude 8.0) is 39"
north of an 8.0 magnitude star (SAO 139617) in Virgo, at
approximately 5:45
12/3 Mars is at the descending node at 1:00; Uranus is at eastern
quadrature at 5:00; the Moon is 0.48 degree northwest of asteroid 7
Iris; Saturn (heliocentric longitude 139.1 degrees) and Neptune
(heliocentric longitude 319.1 degrees) are at heliocentric opposition
at 12:00
12/4 The earliest end of evening twilight for 2006 occurs this
evening; the nearly Full Moon is 0.65 degree northwest of the center
of the bright open cluster M45 (the Pleiades) in Taurus at 3:00
12/5 The Full Moon (known as the Before Yule, Cold, Long Nights,
and Oak Moon) occurs at 0:25; Saturn is 4.9 degrees west-northwest of
the first magnitude star Regulus at 20:00
12/6 Saturn is stationary in right ascension, with retrograde
(western) motion to commence, at 18:00; a maximum lunar libration of
8.6 degrees occurs at 19:00
12/7 The earliest sunset of 2006 at 40 degrees north occurs at
21:35; the Moon is 2.4 degrees south of the first magnitude star
Pollux at 23:00
12/9 The Moon is 1.9 degrees north-northeast of the bright open
cluster M44 (the Beehive Cluster or Prasepe) at 2:00
12/10 Mercury (-0.6) is 0.97 degree north-northeast of Mars
(magnitude 1.5) at 6:00; Saturn is 1.1 degrees south-southwest of the
Moon at 12:00 - an occultation takes place in Norway, Great Britain,
Iceland, and most of Greenland; Mercury, Mars, and Jupiter lie within
a 1.01 degree diameter circle at 14:00; Mercury (magnitude -0.6) is
0.13 degree northeast of Jupiter (magnitude -1.7) at 19:00; the Moon
is 1.3 degrees north-northeast of Regulus at 22:00
12/11 Mars (magnitude 1.5) is 0.79 degree south of Jupiter
(magnitude -1.7) at 15:00
12/12 Last Quarter Moon occurs at 14:32; the Moon is at the
descending node (longitude 170.8 degrees) at 15:20
12/13 A minimum lunar libration of 1.5 degrees occurs at 11:00; the
Moon is at apogee, subtending 29'33" from a distance of 404,418
kilometers, at 19:00
12/14 Venus is at its greatest declination south (-24.2 degrees) at
4:00; the peak of the Geminid meteor shower (100 per hour) occurs at
11:00
12/15 Mercury is 4.9 degrees north-northeast of the first magnitude
star Antares at 2:00; the Moon is 0.73 degree southwest of the first
magnitude star Spica at 10:00 - an occultation takes place in the
southern portion of South America
12/17 Mercury is at the descending node at 13:00
12/18 The Sun enters Sagittarius (ecliptic longitude 266.42 degrees)
at 12:00; Pluto is in conjunction with the Sun at 12:00; Jupiter is
5.5 degrees north of the Moon at 19:00
12/19 Mars is 4.7 degrees north of the Moon at 2:00; the Moon is 0.43
degrees southwest of Antares at 3:00 - an occultation takes place in
New Zealand, southeast Australia, and east Africa; Mercury is 4.7
degrees north of the Moon at 18:00
12/20 Mars is 4.4 degrees north of Antares at 4:00; New Moon
(lunation 1039) occurs at 14:01
12/21 Venus is 3.5 degrees north of the Moon at 17:00
12/22 The winter solstice occurs at 00:25; the peak of the Ursid
meteor shower (10 per hour) occurs at 19:00
12/24 Neptune is 2.4 degrees north-northwest of the Moon at 5:00
12/25 The equation of time equals zero (clocks and sundials are in
agreement) at 10:00; Uranus is 0.26 degree southwest of the Moon at
22:00 - an occultation takes place in Portugal, northeastern Africa,
and the western and northwestern portions of South America
12/26 The Moon is at the ascending node (longitude 349.2 degrees) at
10:35
12/27 First Quarter Moon occurs at 14:48; Mars is at heliocentric
conjunction with Jupiter (heliocentric longitude 242.3 degrees) at
19:00; Venus is at aphelion at 20:00; Mercury is at aphelion at 21:00
12/28 The Moon is at perigee, subtending 32'16" from a distance of
370,323 kilometers, at 2:00
12/31 The Moon is 0.72 degrees northwest of the center of M45 at 11:00
The Moon occults the Pleiades on the evening of December 3. For more
on the event, browse http://lunar-
occultations.com/iota/2006plnam/pleiadna.htm
Times and dates for the lunar light rays predicted to occur this
month are available at www.lunar-
occultations.com/rlo/rays/rays.htm
The planets on December 1: Mercury (-0.7 magnitude, 6.0", 76%
illuminated), Venus (-3.8 magnitude, 9.9", 99% illuminated), Mars
(1.6 magnitude, 3.7", 100% illuminated), Jupiter (-1.7 magnitude,
31.0", 100% illuminated), Saturn (0.4 magnitude, 18.6", 100%
illuminated), Uranus (5.9 magnitude, 3.5", 100% illuminated), Neptune
(7.9 magnitude, 2.2", 100% illuminated), and Pluto (14.0 magnitude,
0.1", 100% illuminated)
Mercury (which is still undergoing its best morning apparition of
2006), Mars, and Jupiter fit within a circle with a 5 degree diameter
from December 7 to December 14 and a 2 degree circle from December 9
to December 11. On December 10, Mercury and Jupiter are separated by
17'. Mars and Jupiter are 48' apart on December 11. Prior to dawn
on December 10, the three planets come within a degree of each other,
the closest approach of three naked-eye planets from 1980 through
2050. (The 2.5 magnitude binary star Beta Scorpii (Graffias) fits
into a 1.1 degree diameter circle with the three planets that
morning.) Unfortunately, the planetary trio will be very low in the
east-southeast during morning twilight so clear skies and good
horizons will be necessary to see them.
By the end of December, Venus will be visible once again in the
southwest shortly after sunset.
Saturn rises at approximately 8:00 p.m. EST by the end of the month.
A minimum ring tilt for the year of 12.3 degrees occurs early in the
month. Titan (magnitude 8.3) is due north of the planet on the
mornings of December 3 and December 19. It is due south of Saturn on
the mornings of December 11 and 27. Saturn's odd satellite Iapetus,
which is brighter by five times when it farthest west of the planet
than when it is at eastern elongation, is due east of Saturn by the
listed separations on the following dates: December 1 (13"), December
6 (26"), December 11 (35"), December 16 (40"), December 21 (38"),
December 26 (31"), and December 31 (19"). Iapetus shines at 11.9
magnitude when it is at greatest eastern elongation on December 18.
Uranus is located less than one degree south of the fourth magnitude
star Lambda Aquarii.
Neptune, in Capricornus, becomes increasingly more difficult to
observe as the month progresses.
Since Pluto is in conjunction with the Sun on December 18, it is not
visible this month.
Comet 4P/Faye travels eastward through Cetus during December. The
periodic comet passes north of the Seyfert galaxy M77 on December 27
and crosses the path of the binary star Gamma Ceti (magnitudes 3.5
and 7.3, separation 2.8") on December 29.
Asteroid 7 Iris enters eastern Aries this month. It is occulted by
the Moon at approximately 4:00 a.m. EST on December 3.