今天的APOD,鲸鱼星系NGC 4631
2009 May 2
The Whale Galaxy
Credit &Copyright: Adam Block,Mt. Lemmon SkyCenter,U. Arizona
Guest Astronomers: Tom Bash and Craig Gates
Explanation:
NGC4631 is a big beautiful spiral galaxy.Seen edge-on, it liesonly 25 million light-years away in the well-trained northernconstellationCanesVenatici.The galaxy's slightly distorted wedge shape suggests tosome a cosmic herring and to others its popular moniker,The Whale Galaxy.Either way,it is similar in size to our own Milky Way.In thisgorgeous color image, the galaxy's yellowish core, dark dust clouds,bright blue star clusters, and red star forming regions are easyto spot.A companiongalaxy, the small elliptical NGC 4627, is just above theWhale Galaxy.Out of view, off the lower edgeof the picture lies another distorted galaxy, hockey stick-shapedNGC 4656.The distortions and minglingtrailsof gas and dust detected at otherwavelengths suggest that all three galaxies have had close encounterswith each other in their past.The Whale Galaxy is also known to have spouteda halo of hot gas glowingin x-rays. |