What's Up in the Night Sky

January 2013 - Vol. 17, No. 1

This Month's Night Sky - NOTE: The next paragraph describes the sky as it appears at 10 pm EST (11 pm EDT) near mid- month. The sky also looks this way at 11 pm EST (midnight EDT) during the beginning of the month and at 9 pm EST (10 pm EDT) by month's end.

Sirius (Canis Major), the brightest star in the night sky, shines brilliantly in the South. It forms the bottom leg of the Winter Triangle. The triangle's upper stars are reddish Betelguese (Orion) to the right and whitish Procyon (Canis Minor) on the left. Capella (Auriga) appears directly overhead later in the evening and you might even glimpse Canopus (Carina) very low (below Sirius) in the South. Looking North you will find the "Big Dipper" (Ursa Major) with its handle still pointing towards the horizon. Cassiopeia's famous "W" asterism is high in the Northwest and Regulus (Leo) shines in the East. Don't forget to look for Castor and Pollux (Gemini "twins") above the Winter Triangle.

MERCURY will not be visible this month. VENUS is bright in the morning sky but continues to fade as it approaches superior conjunction on March 28. JUPITER continues to dominate the night sky, shining brightly in Taurus for most of the night. MARS sets in the early evening, soon to disappear in the Sun's glare for a long hiatus in 2013. SATURN appears earlier every morning, moving into Libra. Outer planets NEPTUNE and URANUS are still visible for telescopic observations this month.

Review how to determine Angular Measurement.

Calendar of Events

NOTE: For those observers not in the ET zone, convert the calendar times to your zone's time by subtracting one hour for CT, two for MT and three for PT. Don't forget to adjust for Daylight Savings Time when necessary by subtracting one hour from your planisphere's time. Dawn and dusk times must also be corrected. See your local newspaper, TV news, or cable TV's Weather Channel for sunrise and sunset times. Unfortunately some of these events may occur during daylight hours in your area.

DATE	EVENT
01	Moon in conjunction with Regulus. Asteroids Ceres and Vesta are still close together in the constellation of Taurus.
02	Earth at perihelion. (closest to the Sun)
03	The Quadrantids meteor shower has a rate of 40 meteors per hour. Observers in N America, dress for the weather! Observations best after midnight.
05	Waning moon near Spica and Saturn. Look to the W about 1 hour before sunrise. Spica is occulted by the Moon from Australia and Antarctica.
10	Venus 3 deg S of Moon. Moon at perigee.
13	Mars 6 deg S of the Moon.
14	Neptune 6 deg S of Moon.
17	Uranus 5 deg S of the Moon.
19	Mercury in superior conjunction.
21	Jupiter N of Aldebaran. In conjunction with the Moon, the planet and Moon come within 2 deg of each other.
22	Moon at apogee.
26	Full Moon near the Beehive cluster. How many bees (stars in the cluster) can you see?
31	Saturn near Alpha Librae, Zebenelgenubi.

Lunar Almanac for January 2013

Phases of the Moon	Phase and Date(s)	Best viewed before local midnight
	New 11	Deep Space Objects
	1st. Qtr 18	Planets & Moon
	Full 26	Moon
	Last Qtr 04	Deep Space & Planets

Topic of the month: Orion, Part II

The Winter sky boasts of one of the most popular constellations, Orion. Indeed, the three belt stars were mentioned in the Bible as being bound together and, indeed they are. Together they were born and together they will die.

One of the brightest and most beautiful diffuse nebula in the sky, the Great Nebula in Orion (M42) is visible with the naked eye. Astrophotos will show off its beautiful colors, but the human eye sees a faint green glow, if any color is detected at all. A fabulous mixture of bright stars and reflection nebula, the Great Nebula is not soon forgotten. In the heart of M42 is the Trapezium, a multiple star system roughly shaped like its namesake. They has ben identified as Theta Orionis. These stars were created out of the dust and gas that is highly concentrated in this area of the sky. The stars themselves have blasted away the interstellar dust, so that they appear to reside in a dark hollow at the heart of the nebula. The young stars are also variable and it can be interesting to telescopic observers to see how many they can identify on any given night. Usually, the four brightest stars, designated by alphabet letter, A, B, C, and D, can be easily found. The C component is the bright star, a little brighter than sixth magnitude and at the threshhold of naked eye brightness. Components a and B are known to be eclipsing binaries. Two identified members of this multiple star are designated as E and F and may be seen by keen observers with telescopes. M43 is a portion of the Great Nebula that is a bit detached from the main body and has it's own designation. (For an image of the Great Nebula in Orion, go to Astronomy Picture of the Day.)

M78 (NGC 2068) is north of the great Orion Nebula and has been mistaken for a comet by telescopic observers. It consists of two B-type stars that are enclosed in a wispy nebula. Also nearby is the object NGC 1999, another star cluster surrounded by nebulosity. Another famous object near the great Orion Nebula is called the Horsehead Nebula (IC 434). Located near the belt star, Zeta Orionis, although to some people, the dark and light nebular patches say it looks to them like a full sized horse, seen from behind with his head turned back toward the observer.

There are two other faint nebulae in the constellation, Barnard's Loop and the Flame Nebula (NGC 2024), but these are beyond the typical back yard observers. Barnard's Loop is huge, about 300 light years across. It is well seen on long exposures of the Orion constellation and some observers report being able to see it in the night sky. It may be the remenant of a supernova explosion that took place 2 million years ago. These nebulae are also members of the Orion Molecular Cloud Complex, that is part of the Milky Way's Orion Arm. This is one of the most intense regions of stellar formation recognized in the Milky Way, approximately 1,500 light-years distant from Earth.

--See You Under the Stars!
Astra for Astra's Almanac