Skip to Navigation | Skip to Content

Previous image Up to Astr111 Index Next image ASTR 110 Photography Projects, Fall 2016

Messier 81 (NGC 3031) & Coddington's Nebula (IC 2574)
Marshall Campbell & Victoria Sanchez

NGC 3031 IC2574
NGC 3031 - Marshall Campbell IC 2574 - Victoria Sanchez

"A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems" (What is a galaxy, 2015). Galaxies are held together with gravitational force. The NGC 3031 galaxy pictured above is an example of a spiral galaxy while IC 2574 is an irregular galaxy. There are three different types galaxies: Spiral galaxies, Elliptical galaxies,and Irregular galaxies. Spiral galaxies "have curved arms that make it look like a pinwheel. Other galaxies are smooth and oval shaped. They’re called elliptical galaxies. And there are also galaxies that aren’t spirals or ovals. They have irregular shapes and look like blobs" (What is a galaxy, 2015).

NGC 3031 is also known as Messier 81 and is a spiral galaxy which means that it is a flat disk of gases, dust and stars rotating around a central bulge of stars (Spiral Galaxy, 2016). This galaxy is part of the Ursa Major Constellation and is approximately 12 million light years away from the Earth (Messier 81, 2016). The distinctive features of Messier 81 are its relatively close location to the Earth, bright appearance, and "large size" (Messier 81, 2016).

IC 2574 is a dwarf irregular galaxy that is 12 million light years away from the Earth. A dwarf irregular galaxy often has "low level of metallicity and relatively high levels of gas." They are also "thought to be similar to the earliest galaxies that populated the Universe" (Irregular galaxy, 2016). "IC2574 is commonly known as Coddington's Nebula after the American astronomer Edwin Coddington, who discovered it in 1898." (Faint galaxy with popping pink features).

Both of these galaxies are about 12 million light years away which makes them relatively close to the Earth (Faint galaxy with popping pink features; Messier 81, 2016). In fact both NGC 3031 and IC 2574 are in the constellation Ursa Major. Stars and gases in both galaxies emit the light that is seen in the photographs shown.

The two galaxies shown, differ greatly mainly because they are different types of galaxies. As a spiral galaxy, NGC 3031 has several arm like spirals surrounding its central bulge while IC 2574 consists of several blob-like collections of stars. NGC 3031 gives off a yellow-gold glow which indicates that it is cooler than the blue-purple Irregular galaxy IC 2574. NGC 3031 is also larger than IC 2574 making it easier to see. NGC 3031can be seen with binoculars making it popular to amateur astronomers (Messier 81, 2016). This might give a good reason as to why NGC 3031 was discovered 124 years before IC 2574. NGC 3031 was discovered in 1774 and IC 2574 was discovered in 1898 (Messier 81, 2016) (Faint galaxy with popping pink features).


Faint galaxy with popping pink features. (n.d.). In Hubble Space Telescope . Retrieved from

Irregular galaxy. (2016, November 12). In Wikipedia. Retrieved November 17, 2016, from

Messier 81. (2016, November 13). In Wikipedia. Retrieved November 15, 2016, from

Spiral galaxy. (2016, October 26). In Wikipedia. Retrieved November 15, 2016, from

What is a galaxy?. (2015, September 8). In NASA Space Place: Explore Earth and Space. Retrieved from


Object Messier 81 (NGC 3031) Coddington's Nebula (IC 2574)
Right Ascension (J2000) 09h 55m 33.2s 10:28:22
Declination (J2000) +69° 3′ 55″ +68:25:00
Filters used B, Clear, R, V B, Clear, R, V
Exposure time per filter

Blue: 3E+002/[sec]

Clear: 1E+002/[sec]

Red: 1E+002/[sec]

Green (V): 2E+002/[sec]

Blue: 1.2E+002 / [sec]

Clear: 1E+002 / [sec]

Red: 8E+001 / [sec]

Green (V): 8E+001

Image dimension 23.66X15.95 13.41X11.03
Date/time observed October 7, 2016 02:38am UTC October 18, 2016 11:47am UTC



Secondary content.


Side content.