Orion, one of the most recognizable of all the winter constellations, will be high in the southern sky on Saturday night, providing an opportunity for good viewing of its large nebula where stars are being born.
About nine pm Saturday, look for Orion nearly due south and about half way up the sky over New Hampshire. This constellation, also known as The Hunter, can easily be found by first looking for his belt consisting of three stars, close together and in nearly a straight line. This is Orion’s distinguishing characteristic.
Above the belt and looking at the shoulder on your left (his right side, were he facing you), you will find a bright red star. This is Betelgeuse, often the brightest star in Orion. This star is nearing the end of its life, and will one day (probably within a million years) explode, possibly becoming visible even in daytime from the Earth. This star is so large that were it to be placed in the center of our solar system, it would easily engulf the Sun, Mercury, Venus, Earth, Mars, the asteroid belt, and likely Jupiter as well.
The star has a red color is because it is a rather cool star – the surface temperature is only about 3,200 degrees Celsius (5,800 degrees Fahrenheit). Compare that to the surface of the Sun, which has a surface temperature near 5,500 degrees Celsius (nearly 10,000 degrees Fahrenheit).
Another bright star of interest to look at in Orion is Rigel. Look for this bluish star as the left foot of Orion (to your right and at the bottom of the constellation). Like Betelgeuse, this is another giant star, but it is much younger than it’s reddish counterpart.
The real treat of Orion, however, is the Orion Nebula, the largest of the three nebulae in the constellation. Look for this fuzzy patch of light as the middle of three “stars” that make up the hunter’s sword, hanging from his belt. This is not a star, but a stellar birthplace. Thousands of stars are being born here in a gigantic cloud of hydrogen and helium. About 1,300 light years from Earth, the nebula stretches twenty-four light years across. It is one of the most photographed objects in the night sky and is a stunning view in binoculars.
Hunt down these three special sights in one constellation this weekend for a trio of treats.