M1

From South Dublin Astronomical Society

M1
Type	Supernova remnant
NGC	NGC 1952
Constellation	Taurus
Right Ascension	5h 34.5m
Declination	+22° 01’
Magnitude	8.4
Size	6x4 arc min.
From Dave Grennan http://webtreatz.com

A unique object in the handbook is the famous Crab Nebula supernova remnant which is listed as the first entry in Messier’s catalogue. The nebula is the debris from a star that exploded near Zeta Tauri and was chronicled by Chinese astronomers as first appearing on July 4, 1054 AD. The “guest star” was visible to the naked eye during the day for many months, reaching magnitude -6, and remained on view for two years before fading from sight. The supernova remnant itself was found by English astronomer John Bevis in 1731. The nickname was given by the Third Earl of Rosse who observed the object with the 72-inch telescope in Birr Castle. The nebula itself lies 1º northwest of Zeta Tauri, marking one of the horns of the Bull, but can prove elusive. Medium-to-giant binoculars will let you spot the Crab as a tiny patch of light — in lower powers it looks stellar.

Since the Supernova that gave us M1 was relativly recent, it is possible to see the expansion of M1. http://www.irishastronomy.org/user_resources/files/1097987164-crab2.swf 700kb. This is a morphed animation, by Albert White, is of two photographs taken 40 years apart; 1951 (POSS I) and 1991 (POSS II). It simulates the expansion of the nebula over this time. While both images are apparently of the same are and size the stars on the left do move, exagerrating the expansion on that side. You can also make out what I assume is the proper motion of a star in the top right corner.