Astronomy Picture of the Day
Posted By admin On February 24, 2011 @ 10:48 pm In Photo Essays | Comments Disabled
[1]
NGC 4449: Close-up of a Small Galaxy
Credit: Data - Hubble Legacy Archive [2], ESA [3], NASA [4]; Processing - Robert Gendler [5]
Explanation: Grand spiral galaxies [6] often seem to get all the glory. Their young, blue star clusters and pink star forming regions along sweeping spiral arms [7] are guaranteed to attract attention. But small irregular galaxies form stars too, likeNGC 4449 [8], about 12 million light-years distant. Less than 20,000 light-years across, the small island universe is similar in size, and often compared [9] to our Milky Way’s satellite galaxy, the Large Magellanic Cloud [10] (LMC). This remarkable Hubble [11] Space Telescope close-up of the well-studied [12] galaxy was reprocessed to highlight the telltale reddish glow of hydrogen gas. The glow traces NGC 4449′s widespread star forming regions, some even larger than those in the LMC [13], with enormous interstellar arcs and bubbles blown by short-lived, massive stars [14]. NGC 4449 is a member of a group of galaxies [15] found in the constellation Canes Venatici. Interactions with the nearby galaxies [16] are thought to have influenced star formation in NGC 4449.
Visit the NASA/JPL website to view more Astronomy Pictures of the Day [17]
Article printed from Recorder Online: http://www.berthoudrecorder.com
URL to article: http://www.berthoudrecorder.com/2011/02/24/astronomy-picture-of-the-day-20/
URLs in this post:
[1] Image: http://www.berthoudrecorder.com/wp-content/uploads/2011/02/NGC4449_hlaGendlerL.jpg
[2] Hubble Legacy Archive: http://hla.stsci.edu/
[3] ESA: http://www.esa.int/
[4] NASA: http://www.nasa.gov/
[5] Robert Gendler: http://www.robgendlerastropics.com/
[6] Grand spiral galaxies: http://apod.nasa.gov/apod/ap071201.html
[7] spiral arms: http://casa.colorado.edu/~danforth/science/spiral/
[8] NGC 4449: http://www.seds.org/~spider/spider/Misc/n4449.html
[9] compared: http://heritage.stsci.edu/2007/26/supplemental.html
[10] Large Magellanic Cloud: http://apod.nasa.gov/apod/ap101016.html
[11] This remarkable Hubble: http://www.robgendlerastropics.com/NGC4449-HST-Gendler.html
[12] well-studied: http://arxiv.org/abs/astro-ph/0010515
[13] in the LMC: http://apod.nasa.gov/apod/ap060518.html
[14] massive stars: http://apod.nasa.gov/apod/ap991130.html
[15] group of galaxies: http://www.atlasoftheuniverse.com/galgrps/cvni.html
[16] galaxies: http://seds.org/MESSIER/galaxy.html
[17] Astronomy Pictures of the Day: http://antwrp.gsfc.nasa.gov/apod/
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