Date: 26 April 2022
Altitude: 59 - 64 degrees
Angular Size: 1° 00' x 0° 45'
Position Angle: 1° 01' from north through east
Orientation: North up; East left
Pixel scale: 1.30" per pixel
Total exposure time: 62 minutes
B filter: 33 x 45 seconds
V filter: 33 x 37 seconds
R filter: 33 x 30 seconds
Messier 101 is also known as NGC 5457 and the “Pinwheel Galaxy”
Galaxy: classification SABc
Constellation: Ursa Major
Diameter: 200,000 light years
Distance: 21 million light years
Age: 330 million years
The galaxy is asymetrical due to interactions with other galaxies. It has a high population of H
II regions, many of which are very large and bright due to ionizaton by large numbers of ex-
tremely bright and hot young stars. Some of these are prominent enough to receive New
General Catalogue numbers.
The galaxy was discovered by Pierre Méchain in 1781, and verified by Charles Messier, who
included it as one of the final entries in the Messier Catalogue.