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Zodiac: Sagittarius
Nov 23 - Dec 21
Read more about Sagittarius.
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Messier 101 (Pinwheel Galaxy)

Messier object number 101 (NGC 5457) is a spiral galaxy and in the constellation of Great Bear. It is also known as the Pinwheel Galaxy. It is approximately 21 million lightyears away from earth.
The Pinwheel Galaxy is a spiral galaxy, just like our own Milky Way Galaxy. However, while our own galaxy hosts "only" around 100 billion stars, the Pinwheel Galaxy is really huge, with an estimated one trillion stars. It is around 50-70% larger in size and sits at distance of around 21 million light years. That means, the light we see today travelled 21 million years through space before reaching us. Looking at the Pinwheel Galaxy is like looking 21 million years into the past.
The Pinwheel Galaxy is also known as Messier Object 101 (M101). Charles Messier was a famous astronomer of the 18th and 19th century, who compiled a list of 110 well visible deep sky objects - the Messier Catalog. However, it was not discovered by Messier itself, but by Pierre Méchain in 1781.
Like our Milky Way Galaxy, the Pinwheel Galaxy has a number of much smaller companion galaxies, such as NGC 5204 or NGC 5474.
Right ascension
-9h -56m -42.96s (-149.17900°)
The magnitude (brightness) is measured on a logarithmic scale. Small numbers mean bright stars: A star with a brightness of 1 mag is 100 times brighter that an star with 6 mag.
8.5 mag
not in database
The distance is measured in light years (LY). A light year is the distance, that light travels within one year. 1 LJ is equal to about 5,878,630,000,000 miles.
21 million21 mil ly
not in database
Messier NºMessier Nº
Every star belongs to a constellation, and 12 of those constellations are part of the zodiac.
Ursa Major (Great Bear)
Image credit: European Space Agency & NASA
While we take great care in compiling the data of all astronomical objects in our database, errors can never be ruled out completely. Therefore, no warranty is taken over for the correctness of the data, the descriptions, or the associated images. Staracle cannot be held liable for any damage, direct or indirect, that may result from incorrect data.
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