This
month we feature the constellations Gemini, Orion, and Taurus, prominent
in the western sky about 9:00 PM around the last of April. The Orion
Nebula is only about 20 deg above the horizon, but it should be quite prominent
in a clear sky, an easy object with binoculars and even the naked eye.
As spring progresses, our old friend Orion will eventually drop off the
western edge of our night sky.
Aldebaran,
the prominent orange star in Taurus, is also about 20 deg above the horizon
in the early evening. Taurus is also the home of the Crab Nebula,
a supernova remnant. The Crab, designated M1, was the first of many
fuzzy objects that comet hunter Charles Messier catalogued in the 1700s
so he wouldn't mistake them for his beloved comets.
Gemini
is the home of the Twins, Castor and Pollux (mag 1.2 and 1.6).
Castor is a double star with the two components orbiting their common center
of gravity with a period of about 400 years. The A and B components
are now separated by about 4 arcseconds, fairly easily resolved in a decent
scope. The Eskimo Nebula is a planetary nebula about 0.7 arcminute
across. You can see it in amateur scopes, but you won't get the magnificent
view we saw in a recent Hubble photo. There are also several nice
open clusters in and around Gemini.
You can print a copy of this star chart so you
can take it outside.
