Jan 01

January 2007

Whats Up in the Sky January, 2007

Winter Sky

Except for the weather, this is the start of a great observing season, mainly because there are so many bright stars and constellations visible.

Many folks have a favorite constellation and often it is Orion. The Hunter can be found high in the southeast in the early night sky. He is easily distinguished by the three stars in a line that form his belt and three smaller stars in his sword. The middle star is actually the Great Orion Nebula, a giant cloud of gas and dust out of which new stars are forming. Also known as M42, it is an interesting object for a small telescope.

Surrounding the sword and belt is a rectangle of stars representing Orions shoulders and knees. Compare the upper left and lower right stars. The former, Betelgeuse, is a red giant and the latter, Rigel, is a blue-white giant.

Follow the line of stars in the belt to the left and you can’t miss Sirius, the brightest star visible in our night sky all year.

Above and to the right of Orion look for a small V of stars (Taurus, the Bull) and farther over find the Pleiades – the Seven Sisters. It looks like a tiny dipper – not to be confused with the real Little Dipper on the opposite side of the sky.

Above Orion and close to the star that represents the tip of one of the Bulls horns lies a very interesting object indeed. It is called M1 or the Crab Nebula. Unfortunately, it is not easily visible unless you are at a dark site with a decent telescope, but it is famous nonetheless.

First discovered in 1731, it was found independently by Charles Messier 27 years later when he was searching for a comet. Since it appeared as a faint, fuzzy blur in his telescope (just like a distant comet), Messier decided to make a list of such objects so other comet hunters would not be similarly fooled, hence the designation M1, the first on his list.

The crab nebula is actually a supernova remnant, the remaining cloud of rapidly expanding gasses left over from a star that exploded. In fact, records from medieval China contain an intriguing account of a guest star in Taurus that was visible in the daytime for 23 days. Most astronomers believe this was the supernova explosion whose remnant we now can observe.

Often you can find connections to history up in the sky.

This month in history:

Jan. 1: asteroid Ceres discovered by Giuseppe Piazzi – 1801
Jan. 7: Galileo discovers Callisto, Europa, and Io, moons of Jupiter – 1610
Jan. 13: First women astronauts selected by NASA – 1978
Jan. 24: Voyager 2 flies past Uranus – 1986
Jan. 27: Apollo 1 astronauts Chaffee, White and Grissom die in fire in capsule-1967
Jan 28: Seven astronauts killed when Space Shuttle Challenger explodes during launch – 1986
Jan 31: Explorer 1, first US satellite, launched – 1958

Here are this months viewing highlights:

Planets this month: Venus is low in SW at dusk, moving higher in the sky as month progresses. Mercury may be visible near Venus at months end. Jupiter and Mars are morning stars in SE. Saturn rises over three hours after sunset on Jan. 1, but by the 30th its only 45 min.
Jan. 3: Full Moon; Earth at closest point in orbit around sun – 91.4 million miles.
Jan. 11: Last-quarter Moon.
Jan. 15: Look for crescent Moon, Antares, and Jupiter in SE 90 min. before dawn.
Jan. 18: New Moon.
Jan. 20: Use binoculars to see Venus, two stars, and crescent Moon in WSW one hour after sunset.
Jan. 25: First quarter Moon.

Peter Burkey – SAAA President