* Astronomy

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RE: ASASSN-15lh

Blobrana · L

Spinning Black Hole Swallowing Star Explains Superluminous Event

An extraordinarily brilliant point of light seen in a distant galaxy, and dubbed ASASSN-15lh, was thought to be the brightest supernova ever seen. But new observations from several observatories, including ESO, have now cast doubt on this classification. Instead, a group of astronomers propose that the source was an even more extreme and very rare event - a rapidly spinning black hole ripping apart a passing star that came too close.
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Blobrana · L

Supernova extraordinaire might actually be a black hole's lunch

What we thought was the largest supernova ever observed might in fact be the death gasp of a star being swallowed by a black hole.
The flash, called ASASSN-15lh, was spotted in June 2015 in the All Sky Automated Survey for SuperNovae (ASAS-SN). Later analysis showed it was 200 times more powerful than most supernovae, shining 20 times brighter than the combined output of the entire Milky Way.
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Mystery supernova could be fast-spinning magnetic star

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Colossal star explosion detected

Astronomers have seen what could be the most powerful supernova ever detected.
The exploding star was first observed back in June last year but is still radiating vast amounts of energy.
At its peak, the event was 200 times more powerful than a typical supernova, making it shine with 570 billion times the brightness of our Sun.
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Blobrana · L

Title: ASASSN-15lh: The Most Luminous Supernova Ever Discovered
Author: Subo Dong (KIAA-PKU), B. J. Shappee (Carnegie), J. L. Prieto (UDP), S. W. Jha (Rutgers), K. Z. Stanek (Ohio State), T. W.-S. Holoien (Ohio State), C. S. Kochanek (Ohio State), T. A. Thompson (Ohio State), N. Morrell (LCO), I. B. Thompson (Carnegie), U. Basu, J. F. Beacom, D. Bersier, J. Brimacombe, J. S. Brown, Ping Chen, E. Conseil, A. B. Danilet, E. Falco, D. Grupe, S. Kiyota, G. Masi, B. Nicholls, F. Olivares, G. Pignata, G. Pojmanski, G. V. Simonian, D. M. Szczygiel, P. R. Wozniak

We report the discovery and early evolution of ASASSN-15lh, the most luminous supernova ever found. At redshift z=0.2326, ASASSN-15lh reached an absolute magnitude of M_{u,AB} ~ -23.5 and bolometric luminosity L_bol ~ 2.2x10^45 ergs/s, which is >~ 2 times more luminous than any previously known supernova. Its spectra match the hydrogen-poor sub-class of super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are poorly understood. In contrast to known SLSNe-I, most of which reside in star-forming, dwarf galaxies, its host appears to be a luminous galaxy (M_V ~ -22; M_K ~ -25.1) with little star formation. In the two months since its first detection, ASASSN-15lh has radiated ~7.5x10^51 ergs, challenging the popular magnetar model for the engine of SLSNe-I.

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ATel 7774: Follow-up observations of ASASSN-15lh establish it as the most luminous supernova ever discovered