IC 2497
Encyclopedia
IC 2497 is a spiral galaxy
close to the intergalactic cloud Hanny's Voorwerp
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IC 2497 is a former quasar
, whose light lit up Hanny's Voorwerp, which is now a light echo of that extinct quasar. It is about 45000 ly away from Hanny's Voorwerp. The quasar shut down sometime in the last 70,000 years. This revises current theories of quasar operation, as the quasar is quiescient, shutting down much faster than was thought possible, and is much cooler than predicted. The galaxy is currently 100 to 10,000 times dimmer than it was when its quasar burned into Hanny's Voorwerp. It is currently the nearest known quasar, being 730 million light years away, and the one with the best view of its host galaxy. The nearest active quasar is 3C 273, 1.7 billion light years further away.
Spiral galaxy
A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...
close to the intergalactic cloud Hanny's Voorwerp
Hanny's Voorwerp
' , Dutch for Hanny's object, is an astronomical object of unknown nature. It was discovered in 2007 by Dutch school teacher Hanny van Arkel, while she was participating as an amateur volunteer in the Galaxy Zoo project...
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IC 2497 is a former quasar
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
, whose light lit up Hanny's Voorwerp, which is now a light echo of that extinct quasar. It is about 45000 ly away from Hanny's Voorwerp. The quasar shut down sometime in the last 70,000 years. This revises current theories of quasar operation, as the quasar is quiescient, shutting down much faster than was thought possible, and is much cooler than predicted. The galaxy is currently 100 to 10,000 times dimmer than it was when its quasar burned into Hanny's Voorwerp. It is currently the nearest known quasar, being 730 million light years away, and the one with the best view of its host galaxy. The nearest active quasar is 3C 273, 1.7 billion light years further away.
Further reading
- Astrophysical Journal Letters, "The Sudden Death of the Nearest Quasar", Kevin Schawinski, Daniel A. Evans, Shanil Virani, et al., Volume 724, Number 1, Page L30, 1 November 2010, ,
- Astronomy and Astrophysics, "Hanny's Voorwerp - Evidence of AGN activity and a nuclear starburst in the central regions of IC 2497", Rampadarath, H.; Garrett, M. A.; Józsa, G. I. G.; et al., Volume 517, L8, July 2010, ,
- Astronomy and Astrophysics, "Revealing Hanny's Voorwerp: radio observations of IC 2497", Józsa, G. I. G.; Garrett, M. A.; Oosterloo, T. A.; et al., Volume 500, Issue 2, 2009, pp. L33-L36, June 2009, , ,