Messier 1 (M1)
Common Name: Crab Nebula
Also Known as: NGC 1952, Sharpless 242, LBN 833, 3C 144
Object Type: Supernova Remnant
Constellation: Taurus
Distance from Earth: 6,523 light years
Apparent Magnitude: 8.4
Coordinates: RA 5H 34M 32S DEC +22 deg 0 min 52 sec
Actual Size: 11 light years in diameter.
Apparent Dimensions: 420 arc-minutes x 290 arc-minutes.
Discovered by: The Crab Nebula was discovered by the English astronomer John Bevis in 1731. Bevis added the object to his sky atlas Uranographia Britannica, which was completed in 1750 but never published. Charles Messier discovered the nebula independently on August 28, 1758 while looking for a bright comet and entered it as the first object in his catalogue on September 12.
Description: M1 is the only supernova remnant listed in Messier’s catalogue and the most famous object of its kind in the night sky.
The nebula has a total luminosity 75,000 times that of the Sun and lies at a distance of 6,500 light years from Earth.
The Crab Nebula is the result of a supernova explosion, SN 1054, that was observed by Chinese astronomers in 1054 AD.
It was the first deep sky object to be associated with a historical supernova explosion. Chinese astronomers watching the sky on July 4, 1054 noted the appearance of a new star
just above the southern horn of Taurus.
For 23 days it was supposedly bright enough to be visible during the day, shining six times brighter than Venus. It was visible with the naked eye for 653 days (almost 2 years).
The explosion of the progenitor star produced a large shell of filaments
that has continued to expand ever since and will eventually disperse and disappear into the surrounding space.
It continues to expand at more than 3 million mph. The filaments of the Crab Nebula are what is left of the progenitor star’s atmosphere and they mainly consist of ionized hydrogen
and helium, along with other elements including oxygen, carbon, iron, nitrogen, sulfur and neon.
The temperatures of the filaments are typically in the range from 11,000 to 18,000 K.
Click Below Image(s) for Full Size:
In 1967 a fluctuating radio source was identified in a position coinciding with the Crab Nebula. The object is a rapidly spinning pulsar a few tens of miles across that flashes about 30 times a second. Known as NP0532 (or the Crab Pulsar) the neutron star is the remains of
the supernova.
M1 can just barely be seen with the naked eye in a dark sky. Best viewing is between November-January.
Plate Solved Image
M1 Crab Nebula
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