What's Up in the Night Sky

January 2020 - Vol. 24, 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 Betelgeuse (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 be too close to the Sun to be seen most of the month, reaching superior conjunction on the 10th. The planet returns to the evening sky shining at -1.0 mag at the end of the month. VENUS will rise higher in the evening sky for the northern hemisphere. The year 2020 and bring a dazzling light as Venus opens the year at -4.0 mag. MARS in the morning sky will brighten up to 1.4 mag by the end of the month. JUPITER returns to the the morning sky mid-month. SATURN reaches solar conjunction on the 13th and will not be readily observed this month. URANUS reaches its stationary point on the 11th and will resume its slow forward motion, visible among the stars of Aries. NEPTUNE maybe found in the evening sky.

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 or check with the U.S. Naval observatory. Unfortunately some of these events may occur during daylight hours in your area.

DATE	EVENT
02	Moon at apogee.
04	Quadrantids meteor peak. Up to 120 meteors per hour have been recorded near the peak, this will occur at 9 hours UT. These meteors come from a radiant in the constellation of Bootes. For observing information, check out this article at the American Meteor Society.
05	Earth at perihelion.
09	Moon 1.5 deg S. of M-35 star cluster.
10	Mercury at superior conjunction. Penumbral lunar eclipse not visible from N. America.
11	Uranus stationary.
12	Moon 1.0 deg N. of M-44 (Beehive) star cluster.
13	Saturn in conjunction with the Sun. Moon at perigee.
19	Mercury at greatest heliocentric lat. S.
20	Mars 2 deg. S. of Moon.
23	Jupiter .4 deg. N. of Moon, occultation from Madagascar, Kerguelen Is., S. & E Australia, New Zealand, S & E Melanesia, SW Polynesia.
27	Venus .08 deg S. of Neptune.
28	Venus 4.0 deg. N. of Moon.
29	Moon at apogee.

Lunar Almanac for January 2020

Phases of the Moon	Phase and Date(s)	Best viewed before local midnight
	New 24	Deep Space Objects
	1st. Qtr 03	Planets & Moon
	Full 10	Moon
	Last Qtr 17	Deep Space & Planets

Topic of the month: Orion, the Great Nebula, and the Sword

Orion star chart The January sky shines with our winter favorites, Orion, Gemini and Canis Major, virtually invisible all summer long. The constellation of Orion is thought to represent a great hunter, with his two hunting dogs (Canis Major and Canis Minor.) This constellation boasts of two first magnitude stars, the red giant Betelgeuse and the brilliant blue star Rigel. Three second magnitude stars form a line in the giant's center section: Alnitak, Alnilam, and Mintaka. These stars have been known as the Three Kings as well as the Three sisters. The "head" of this giant figure is poorly represented by three stars in a triangle shape. The brightest and best known of these is Lambda, a double star.

Many observers tune into the Great Nebula in Orion, that is part of the sword this hero carries. The Orion Nebula is considered the most observed object in the sky. The great nebula is about 1,500 light-years away and it is one of the closest star-forming region to Earth. It is known best as M-42, recognized years ago by Charles Messier. At 4th magnitude, M42 can be seen with the naked eye.

In the center of the nebula is the star that has been designated as Theta Orionis. Theta ORI is actually a multiple star, consisting of four primary members that can be easily seen in binoculars especially if the component labeled B is at the brighter phase of it's period. It is also called the Trapezium because of the pattern formed by the 4 largest stars. In a small telescope on a clear night, a fifth component labeled E may also be visible. More difficult is the component F which is close to the brightest star of the group, the C component. Many stars in the Orion Nebula are variable because they are so young. The ultraviolet light streaming from these stars has cleared the dust surrounding them, enabling us to see them shining in their stellar nursery. The Nebula itself is part of the spiral arm of the Milky Way. What a challenge the nebular stars can be to a variable star observer!

Orion's Sword

Orion's sword is one of my favorites both in a telescope and in binoculars. Although the Great Orion Nebula (M42) is a wonderful sight in a good telescope, binoculars show many of the brighter sword objects in a single view. Both M-42 and M-43 are bright diffuse nebulae. They are hard to separate when viewed by binoculars. These are regions where stars are being formed. (At least they were being formed when the light entering your binoculars left the nebula some 1600 years ago!)I like to think of the Orion Nebula as a great bird where M-43 is the head and M-42 is the body of the bird with its wings outspread. NGC 1981 is an open cluster of about 10 stars embedded in a vast dust cloud. These stars are also embedded in a dusty nebula and astrophotos taken in this area reveal a rich, red and blue or violet haze surrounding the stars. Iota Orionis is the brightest star in this area of the field and Struve 747 a double star that can be "split" by tripod mounted 10x50's.

To all northern hemisphere observers, stay warm this month!

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