| 词条 | IC 2497 |
| 释义 |
| name = IC 2497 }}{{Galaxybox image | image = | caption = IC 2497 with Hanny's Voorwerp by HST | credit = NASA, ESA, W. Keel (University of Alabama), and the Galaxy Zoo Team }}{{galaxybox observe | constell = Leo Minor [1] | epoch = J2000.0 [2] | ra = {{RA|09|41|04.076}} [2] | dec = {{DEC|+34|43|58.57}} [2] | appdim_v = 0.390' × 0.320' [2] }}{{galaxybox astrometry | z = 0.051633 [2] }}{{galaxybox catalog | names = IC 2497, LEDA 165538, IRAS 09380+3457, 2MASX J09410407+3443585 }}{{galaxybox end}}IC 2497 is a spiral galaxy[2] close to the intergalactic cloud Hanny's Voorwerp.[3] IC 2497 is a former quasar, whose light lit up Hanny's Voorwerp, which is now a light echo of that extinct quasar.[4] It is about {{convert|45000|-|70000|ly|pc}} away from Hanny's Voorwerp.[5] The quasar shut down sometime in the last 70,000 years.[6] This revises current theories of quasar operation, as the quasar is quiescent, shutting down much faster than was thought possible,[7] and is much cooler than predicted.[5] The galaxy is currently 100 to 10,000 times dimmer than it was when its quasar burned into Hanny's Voorwerp.[8] It is currently the nearest known quasar, being 730 million light years away, and the one with the best view of its host galaxy.[8] The nearest active quasar is 3C 273, 1.7 billion light years further away.[9] References1. ^Sky Factory, "IC 2497", Davide De Martin, 2007 (accessed 2010-11-11) 2. ^BBC News, "Teacher finds new cosmic object", Paul Rincon, 5 August 2008 (accessed 2010-11-11) 3. ^1 2 3 4 5 {{cite simbad|title=IC 2497|accessdate=2010-11-11}} 4. ^ScienceDaily, [https://www.sciencedaily.com/releases/2010/11/101103171638.htm "Cosmic Curiosity Reveals Ghostly Glow of Dead Quasar"], 6 November 2010 (accessed 2010-11-10) 5. ^1 Softpedia, "Shut Down Quasar Found Close By", Tudor Vieru, 3 November 2010 (accessed 2010-10-11) 6. ^Universe Today, "What Hanny’s Voorwerp Reveals About Quasar Deaths", Jon Voisey, 3 November 2010 (accessed 2010-11-11) 7. ^ECN Magazine, "Cosmic Curiosity Reveals Ghostly Glow of Dead Quasar", Yale University, 3 November 2010 (accessed 2010-11-11) 8. ^1 Wired, [https://www.wired.com/wiredscience/2010/11/quasar-shutdown/ "Rare Dead Quasar Found in Nearby Galaxy"], Lisa Grossman, 2 November 2010 (accessed 2010-11-11) 9. ^PhysOrg, "'Cosmic ghost' discovered by volunteer astronomer", Yale University, 5 August 2008 (accessed 2010-10-11) Further reading
5 : Leo Minor|Spiral galaxies|IC objects|LEDA objects|IRAS catalogue objects |
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