Find us on: Home Images Video & Audio News Explore The Mission View Full Screen View in WorldWide Telescope Download Image JPEG 600 x 600 • 109 KB 960 x 960 • 219.4 KB 1500 x 1500 • 345.7 KB 2820 x 2820 • 2 MB TIFF 2820 x 2820 • 12.3 MB About the Image Date 2013-05-16 ID sig13-004 Type Observation Credit NASA/JPL-Caltech/SINGS Team About the Object Name Messier 94 • M94 • NGC 4736 Type Galaxy > Type > Spiral Galaxy > Type > Ring Galaxy > Activity > Starburst Distance 16,000,000 Light Years Redshift 0.001027 Color Mapping Band Wavelength Telescope Infrared 3.6 µm Spitzer IRAC Infrared 4.5 µm Spitzer IRAC Infrared 8.0 µm Spitzer IRAC Infrared 24.0 µm Spitzer MIPS About the Color Mapping Table Astrometrics Position (J2000) RA = 12h 50m 53.1s Dec = 41° 7' 10.6" Field of View 17.6 x 17.6 arcminutes Orientation North is 47.0° right of vertical Constellation Canes Venatici Recent News July 2 Black Hole Fireworks in Nearby Galaxy June 19 Spitzer Spies an Odd, Tiny Asteroid June 12 Catching a 'Wave' of Galaxies Ending the Dark Ages June 4 New Suspect Identified in Supernova Explosion May 28 The 'Serpent' Star-forming Cloud Hatches New Stars May 21 Pitch Black: Cosmic Clumps Cast the Darkest Shadows 05.16.13 Galactic Wheels within Wheels Tweet How many rings do you see in this striking new image of the galaxy Messier 94 (NGC 4736) as seen by the infrared eyes of NASA’s Spitzer Space Telescope? While at first glance one might see a number of them, astronomers believe there is just one. Historically, Messier 94 was considered to have two strikingly different rings: a brilliant, compact band encircling the galaxy’s core, and a faint, broad, swath of stars falling outside its main disk. Astronomers have recently discovered that the outer ring, seen here in the deep blue glow of starlight, may actually be more of an optical illusion. Their 2009 study combined infrared Spitzer observations with ultraviolet data from NASA’s Galaxy Evolution Explorer, and ground-based surveys in visible (Sloan Digital Sky Survey) and near infrared light (Two Micron All Sky Survey). This more complete picture of Messier 94 indicates that we are really seeing two separate spiral arms that, from our perspective, take on the appearance of a single, unbroken ring. The bright inner ring of Messier 94 is very real, however. This area is sometimes identified as a “starburst ring” because of the frenetic pace of star formation in this confined area. Starbursts like this can often be triggered by gravitational encounters with other galaxies, but in this case may instead be caused by the galaxy’s oval shape. Tucked in between the inner starburst ring and the outer ring-like arms we find the galaxy’s disk, striated with greenish filaments of dust. While, at first glance, these dusty arcs look like a collection of rings, they actually follow tightly wound spiral arcs. Messier 94 is about 17 million light years away, making it a distant neighbor of our own Milky Way galaxy. It was first discovered by Charles Messier’s assistant, Pierre Méchain, in 1781 and was added to his supervisor’s famous catalog two days later. Infrared light with wavelengths of 3.6 and 4.5 microns is shown as blue/cyan, showing primarily the glow from starlight. 8 micron light is rendered in green, and 24 micron emission is red, tracing the cooler and warmer components of dust, respectively. The observations were made in 2004, before Spitzer ran out of cryogen. Related Media Feature Article Galaxy's Ring of Fire feature13-03 Image Galactic Wheels within Wheels sig13-004 Latest Images July 2 Black Hole Jets Make Shock Waves July 2 Galactic Pyrotechnics on Display June 19 Solid as a Rock? Porosity of Asteroids June 19 I Spy a Little Asteroid With My Infrared Eye June 19 How to Measure the Size of an Asteroid Feedback • Mailing List • Privacy Policy • Image Use Policy • Credits • Legacy Site The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center.