NGC 278

Cassiopeia’s unusual residentNGC 278 may look serene, but it isn’t. The galaxy is currently undergoing an terrific burst of star formation. The blue knots speckling the galaxy’s spiral arms mark clumps of hot newborn stars. However, NGC 278’s star formation is very unusual. It does not extend all across the galaxy to its outer edges but is only taking place within an inner ring roughly 6500 light-years across. The galaxy’s center is bright, but its extremities are much darker. This odd configuration may have been caused by a merger with a smaller, gas-rich galaxy which ignited the center of NGC 278 while the dusty remains of the smaller galaxy were dispersed into the galaxy’s outer regions. Whatever happened, such a ring of star formation, called a nuclear ring, is extremely rare in galaxies without bars at their centers.

Image Credit: ESA / NASA

M82 on the Radio

m82_gbtThis composite image of starburst galaxy M82 shows the distribution of dense molecular gas as seen by the National Radio Astronomy Observatory’s 85-ft Green Bank Telescope (yellow and red) and the background stars and dust as seen by Hubble (blue). The yellow areas correspond to regions of intense star formation. The red areas trace outflows of gas from the disk of the galaxy.

Image Credit: NARO/NASA


Starburst galaxy Messier 94This is the galaxy Messier 94 which lies about 16 million light-years away. Within the bright ring around Messier 94, new stars are forming at a high rate, so many that that feature is called a starburst ring. This peculiarly-shaped star-forming region is likely the result of a pressure wave going outwards from the galactic center, compressing the gas and dust in the outer region. The compression causes the gas to collapse into denser clouds, and gravity pulls the gas and dust together inside the clouds until temperature and pressure are high enough for stars to be born.

Image Credit: ESA / NASA