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Globular Star Cluster M3
| Title |
Globular Star Cluster M3 |
| Explanation |
This immense ball of half a million stars older than the Sun lies over 30,000 light-years away. Cataloged as M3 [ http://seds.org/messier/m/m003.html ] (and NGC 5272 [ http://www.mporzio.astro.it/~marco/gc/ cluster_4.php?ggc=NGC+5272 ]), it is one of about 150 globular star clusters [ http://en.wikipedia.org/wiki/Globular_cluster ] that roam the halo of our Milky Way Galaxy [ http://www.seds.org/~spider/spider/MWGC/mwgc.html ]. Even in this impressively sharp image [ http://karelteuwen.be/photo_page.php?img=94 ], individual stars are difficult to distinguished in the densely [ http://antwrp.gsfc.nasa.gov/apod/ap031213.html ] packed core, but colors are apparent for the bright stars on the cluster's outskirts. M3's many cool "red" giant stars take on a yellowish cast, while hotter giants and pulsating variable stars [ http://antwrp.gsfc.nasa.gov/apod/ap070415.html ] look light blue. A closer look [ http://www.flemingastrophotography.com/m3dss.html ] at the deep telescopic view also reveals a host of background galaxies. Itself about 200 light-years across, the giant star cluster is a relatively bright, easy target for binoculars in the northern constellation Canes Venatici, The Hunting Dogs [ http://hawastsoc.org/deepsky/cvn/index.html ], and not far from Arcturus [ http://www.astro.uiuc.edu/~kaler/sow/arcturus.html ]. |
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Comet Hyakutake and the Milk
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| Title |
Comet Hyakutake and the Milky Way |
| Explanation |
Two years ago, the Great Comet of 1996 [ http://antwrp.gsfc.nasa.gov/apod/ap960208.html ], Comet Hyakutake [ http://www.jpl.nasa.gov/comet/hyakutake/ ], inched across our northern sky during its long orbit [ http://antwrp.gsfc.nasa.gov/apod/ap960314.html ] around the Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ]. Visible above as the bright spot with the faint tail [ http://antwrp.gsfc.nasa.gov/apod/ap960326.html ] near the picture [ http://www.psiaz.com/polakis/gco/gco.html ]'s center, Comet Hyakutake [ http://encke.jpl.nasa.gov/comets_long/96B2.html ] shares the stage with part of the central band of the Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap970517.html ], prominent in the picture's upper right. Also visible are Antares [ http://antwrp.gsfc.nasa.gov/apod/ap980726.html ], the bright orange star in the upper right, Arcturus [ http://www.windows.umich.edu/the_universe/Arcturus.html ], the bright star on the lower left, and the Pipe Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap970621.html ], which is perhaps harder to find. Comet Hyakutake [ http://antwrp.gsfc.nasa.gov/apod/index/Hyakutake.html ]'s unusually close approach [ http://antwrp.gsfc.nasa.gov/apod/ap960325.html ] to the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap980204.html ] allowed astronomers to learn many things, including that comets can emit much X-ray light [ http://antwrp.gsfc.nasa.gov/apod/ap960411.html ]. |
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