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Stars Without Galaxies
| Title |
Stars Without Galaxies |
| Explanation |
Galaxies are [ http://antwrp.gsfc.nasa.gov/apod/ap990322.html ] made up of stars, but are all stars [ http://antwrp.gsfc.nasa.gov/apod/ap010223.html ] found within galaxies? Using the Hubble Space Telescope, researchers exploring [ http://xxx.lanl.gov/abs/astro-ph/9801228 ] the Virgo Cluster [ http://bozo.lpl.arizona.edu/messier/more/virgo.html ] of galaxies have found about 600 red giant stars adrift in intergalactic space [ http://oposite.stsci.edu/pubinfo/PR/97/02/PR.html ]. Above is an artist's vision of the sky from a hypothetical planet of such a lonely sun. The night sky on a world orbiting an intergalactic star would be a stark contrast to Earth's - which features a spectacle of stars, all members of our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap010202.html ]. As suggested by the illustration, a setting red sun would leave behind a dark sky flecked only with faint, fuzzy, apparitions of Virgo Cluster galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap010126.html ]. Possibly ejected from their home galaxies during galaxy-galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap981219.html ] collisions, these isolated suns may well represent part of a large, previously unseen [ http://oposite.stsci.edu/pubinfo/background-text/ darkmatt.txt ] stellar population, filling the space between [ http://imagine.gsfc.nasa.gov/docs/features/exhibit/ asca_abundance.html ] Virgo Cluster galaxies. |
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Stars Without Galaxies
| Title |
Stars Without Galaxies |
| Explanation |
Galaxies are made up [ http://antwrp.gsfc.nasa.gov/apod/ap961009.html ] of stars, but are all stars found within galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap970125.html ]? Using the Hubble Space Telescope, researchers exploring the Virgo Cluster of galaxies [ http://bozo.lpl.arizona.edu/messier/more/virgo.html ] have now found about 600 red giant stars adrift in intergalactic space [ http://oposite.stsci.edu/pubinfo/PR/97/02/A.html ]. Above is an artist's vision of the sky from a hypothetical planet of such a lonely sun. The night sky on a world orbiting an intergalactic star would be a stark contrast to Earth's - which features a spectacle of stars, all members of our own Milky Way galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap971229.html ]. As suggested by the illustration, a setting swollen red sun would leave behind a dark sky flecked only with faint, fuzzy, apparitions of Virgo Cluster galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap960419.html ]. Possibly ejected from their home galaxies during galaxy-galaxy collisions [ http://antwrp.gsfc.nasa.gov/apod/ap971022.html ], these isolated suns may well represent part of a large, previously unseen [ http://oposite.stsci.edu/pubinfo/background-text/darkmatt.txt ] stellar population, filling the space between [ http://imagine.gsfc.nasa.gov/docs/features/exhibit/ asca_abundance.html ] Virgo Cluster galaxies. |
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The Perseus Cluster of Galax
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| Title |
The Perseus Cluster of Galaxies |
| Explanation |
Here is one of the largest objects [ http://www.actden.com/sky_den/cluster.htm ] that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies [ http://crux.astr.ua.edu/white/mug/cluster/clusters.html ]. We view the cluster through the foreground of faint stars in our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap970315.html ]. It takes light roughly 300 million years to get here from this region of the Universe [ http://antwrp.gsfc.nasa.gov/apod/ap980302.html ], so we see this cluster as it existed before the age of the dinosaurs [ http://www.wf.carleton.ca/Museum/extinction/homepg.html ]. Also known as Abell 426 [ http://users.ox.ac.uk/~jgodwin/tx426.htm ], the center of the Perseus Cluster is a prodigious source of X-ray radiation [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html ], and so helps astronomers explore [ http://lheawww.gsfc.nasa.gov/users/public_html/kaa/ asca_perseus/apjlett.html ] how clusters formed and how gas [ http://antwrp.gsfc.nasa.gov/apod/ap960419.html ] and dark matter interact [ http://physics.hallym.ac.kr/education/stellar/darkmatter/essay.html ]. The Perseus Cluster of Galaxies is part of the Pisces-Perseus [ http://aps.umn.edu/Papers/juan/mapspp.html ] supercluster of galaxies [ http://astrowww.phys.uvic.ca/rsocs/hudson/threed.html ], which spans over 15 degrees and contains over 1000 galaxies. |
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