Astronomy Picture of the Day
Posted By admin On March 13, 2011 @ 10:53 pm In Photo Essays | Comments Disabled
[1]
NGC 4755: A Jewel Box of Stars
Credit & Copyright: Dieter Willasch [2] (Astro-Cabinet [3])
Explanation: The great variety of star colors in this open cluster [4] underlies its name: The Jewel Box [5]. One of the bright central stars is a red supergiant [6], in contrast to the many blue stars that surround it. The cluster [7], also known as Kappa Crucis [8] contains just over 100 stars, and is about 10 million years old. Open clusters [9] are younger, contain few stars, and contain a much higher fraction of blue stars than do globular [10] clusters [11]. This Jewel Box [12] lies about 6,400 light-years [13] away, so the light that we see today was emitted from the cluster before even the Great Pyramids [14] in Egypt [15] were built. The Jewel Box, pictured above [16], spans about 20 light-years, and can be seen with binoculars towards the southern constellation [17]of the cross (Crux [18]).
Visit the NASA/JPL website to view more Astronomy Pictures of the Day [19]
Astronomy Picture of the Day
Article printed from Recorder Online: http://www.berthoudrecorder.com
URL to article: http://www.berthoudrecorder.com/2011/03/13/astronomy-picture-of-the-day-33/
URLs in this post:
[1] Image: http://www.berthoudrecorder.com/wp-content/uploads/2011/03/jewelbox_willasch_big.jpg
[2] Dieter Willasch: http://astro-cabinet.com/about.php
[3] Astro-Cabinet: http://astro-cabinet.com/loggedon.php
[4] open cluster: http://www.seds.org/messier/open.html
[5] The Jewel Box: http://www.seds.org/messier/xtra/ngc/n4755.html
[6] red supergiant: http://apod.nasa.gov/apod/ap100106.html
[7] cluster: http://adsabs.harvard.edu/abs/1963MNRAS.126...11F
[8] Kappa Crucis: http://adsabs.harvard.edu/abs/1984A%26AS...56..373D
[9] Open clusters: http://apod.nasa.gov/apod/open_clusters.html
[10] globular: http://apod.nasa.gov/apod/globular_clusters.html
[11] clusters: http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18009
[12] Jewel Box: http://en.wikipedia.org/wiki/Jewel_Box_%28star_cluster%29
[13] light-years: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980211a.html
[14] Great Pyramids: http://www.pbs.org/wgbh/nova/pyramid/
[15] Egypt: http://en.wikipedia.org/wiki/Egypt
[16] pictured above: http://astro-cabinet.com/showimage.php?&image=NGC4755_3_10m-RGB_final.jpg&lang=english
[17] constellation: http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html
[18] Crux: http://en.wikipedia.org/wiki/Crux_%28constellation%29
[19] Astronomy Pictures of the Day: http://antwrp.gsfc.nasa.gov/apod/
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