#messier 91

[quiltofstars]

M91 // Ralph MacDonald

A barred spiral galaxy, M91 is the faintest object in the Messier catalog and the last group of eight galaxies that Messier discovered in 1781.

This was also a "lost" object for nearly two centuries. Messier made a mistake in logging his observations, writing this galaxies position with respect to M58 instead of M89. Although William Herschel (1738-1822) suspected this mistake in 1784, he was unsure. It took amateur astronomer William C. Williams in 1969 to recover this "lost" galaxy!

[chibinotan]

Supermassive Blackholed Spiral

[therealuniverse]

MESSIER 91 GALAXY M91 (NGC 4548) is a faint barred spiral galaxy in the constellation Coma Berenices and is a member of the Virgo Galaxy Cluster. The galaxy lies about 55 million light years from Earth. It has a very prominent bar structure connected to two outer arms that trail stars and interstellar dust. The distribution of the atomic gas shows a ring-like structure.

When Charles Messier was observing and logging deep space objects on the night of March 18, 1781, chances are very good that M91 was what he was describing when he recorded: “Nebula without stars, fainter than M90″. But, there was a problem… Charles Messier made a rare bookkeeping mistake and logged its position wrong. So, for a long time M91 was a missing Messier object, as Messier had determined its position from M89 while he thought it was from M58. M91 was catalogued as H II.120 by William Herschel in 1784. Navigating using the directions that Messier initially, yet erroneously logged, Herschel thought the object to be NGC 4571, a beautiful but faint barred spiral galaxy. The identity of M91 was corrected by observations by astronomer William C. Williams in 1969. Prior opinions have been that M91 had either been a comet which the great comet hunter Messier mistook for a nebula. Measurements done by the Hubble Space Telescope indicate that M91 is moving away from us at a speed of about 400 km/s (895,000 mph). The galaxy’s particular speed is unusual because the Virgo Cluster is moving away from us at a speed of 1100 km/s (2.4 million mph), indicating M91 must be traveling toward us at 700 km/s (1.5 million mph) relative to the other galaxies in the Virgo Cluster. -JMP http://www.universetoday.com/48349/messier-91/ http://messier.seds.org/m/m091.html Image Credit: Kitt Peak National Observatory (Haynes)/NOAO/AURA/NSF

[quiltofstars]

M91 // Cfreerksen

As an individual galaxy, M91 is a strongly barred galaxy. It is also another "anemic" galaxy, one without a lot of gas and dust and a low rate of star formation. Again, this is likely caused by ram pressure stripping as it interacts with the hot gas that makes up the intracluster medium of the Virgo Cluster.

[quiltofstars]

Markarian’s Chain // Ethan Pearson

Some of the more prominent galaxies include: the pair known as “the Eyes”, M86 (left eye) and M84 (right eye) along with the “mouth” NGC 4388. The galaxy at bottom center is M87, at bottom left is M89 and M90, and the three brightest at top left (from left to right) are NGC 4571, M91, and M88.

[quiltofstars]

M91 (bottom left) and NGC 4571 (top right) // Tim Hutchinson

[chibinotan]

Asteroid at Galaxy’s Outskirts

[spacettf]

A fistful of galaxies by gatoth on Flickr.

Via Flickr: Two bright galaxies in constellation of Coma Berenices: Messier 88 and Messier 91 with a handful of smaller galaxies. Messier 88 (lower left) is nice spiral galaxy 47 million light-years away. Messier 91 (upper right) shows less details, it's distance is 63 million light-years. It's type is barred spiral. Both of them are members of Virgo Cluster of Galaxies.