A magnitude 14.9 supernova, 2006gy, was discovered on the 18th September 2006, by the Texas Supernova Search in the galaxy NGC 1260, in the constellation Perseus.
The supernova is located 2".0 west and 0".4 north of the centre of the galaxy.

Position(2000): R.A. = 03h17m27s.06, Dec. = +41°24'19".5
z = 0.019190

As yet the type is unknown.

See more

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`Irony` actually does mean `metal like`...

SN 2006gy is a type II event, probably caught early in its evolution,
according to a report from a team of Italian astronomers in CBET 647.

I try to keep a list of summary information on the latest SNe on
a web page:

http://stupendous.rit.edu/richmond/sne/sn.list

The Texas Supernova Search sounds like a great project! I'm glad they're doing this.

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Forming opinions as we speak

According to CBET 648 it is not a supernova, but a AGN outburst.

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`Irony` actually does mean `metal like`...

I don't have access to this (Thanks Harvard). Can you give more details on why they think this, and what we should expect in terms of light curve if they are right?

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Forming opinions as we speak

Yes, I would be very interested in this also!

Any other sites or papers on this Blob?

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RussT
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Everything is, as it should be, otherwise, it wouldn't be!

Prieto and Garnavich took spectra of the object with the Kitt Peak 4m telescope. Their suggestion that this might be the outburst of an AGN, rather than a supernova, is based on three observations: the object is at the center of the galaxy, as far as we can tell; the Balmer emission lines are symmetric, which is unusual for a young supernova (they tend to show P Cygni profiles); and using the Na I absorption strength to make a very rough estimate of the reddening to the object, they compute an absolute magnitude of about -22 for the object, which is quite a bit more luminous than a typical SN of any type.

We'll just have to see; it should be pretty clear in a few weeks with additional spectra.

Being at the center of a galaxy isn't a solid indicator, as we see quite a few SN remnants near the center of ours, but the symmetric Balmer lines are a good clue, and the reddening/magnitude is also an indicator of something different.

If you happen to see more about this event's light-curve and spectra in the future, please pass it along. If they are right this is a really cool thing to study.

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Forming opinions as we speak

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`Irony` actually does mean `metal like`...

Title: The brightest supernova ever recorded, powered by the death of an extremely massive star
Authors: Nathan Smith, Weidong Li, Ryan J. Foley, Ryan Chornock, Alexei V. Filippenko, David Pooley, Robert Quimby, J. Craig Wheeler, Joshua S. Bloom, Charles Hansen

Supernovae resulting from the deaths of massive stars span a wide range of peak luminosities, usually reached within 30 days after explosion. Their diversity depends on the star's initial mass and rate of mass loss during its lifetime. Stars born with initial masses above 40 times the mass of the Sun are expected to shed their hydrogen envelopes to expose their He core before they die, resulting in supernovae with little or no evidence for hydrogen gas observed in their spectrum. Here we report on our discovery and follow-up observations of SN 2006gy, which reveal that it reached a peak luminosity at least 3 times greater than any other supernova seen to date, and far greater than most others. We find that a large ejected mass of order 100 Solar masses is required to power its enormous total radiated luminosity, indicating a total kinetic energy of more than 10^52 ergs. This suggests that SN 2006gy marked the demise of an extremely massive star that, contrary to expectations, failed to shed its massive hydrogen envelope. A circumstellar shell that surrounded the progenitor star has a large mass and expansion speed, effectively ruling-out certain types of progenitor stars. Based on a number of lines of evidence, we suggest that the progenitor was a very massive evolved object like eta Carinae, which is the most luminous star known in the Milky Way. These observations suggest that the most massive stars can explode earlier than expected, and can create bright supernovae instead of dying ignominious deaths through direct collapse to a black hole. If such a fate is common, then supernovae from the first stars in the universe, which may have been extremely massive, will be more numerous than previously believed.

Read more (889kb, PDF)

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`Irony` actually does mean `metal like`...

http://arxiv.org/PS_cache/astro-ph/p.../0612408v2.pdf

SN 2006GY: AN EXTREMELY LUMINOUS SUPERNOVA IN THE GALAXY NGC1260
E. O. OFEK, P. B. CAMERON, M. M. KASLIWAL, A. GAL-YAM, A. RAU, S. R. KULKARNI1, D. A. FRAIL, P. CHANDRA,
S. B. CENKO, A. M. SODERBERG & S. IMMLER,
Draft of February 7, 2007

An explanation is also required that would explain why we would see such an event fairly locally, but none of the most distant supernova ever observed are equal to this event in terms of the slow evolution of the light curve. Indeed, if this type of superluminous event is what we are observing in the most distant supernova observed, the light curves (after correction for time dilation) are much too short.

The use of distant supernova (in the mid 1990's) to provide the first definite proof of time dilation did not anticipate that supernova could be this bright, or have light curves that are this long; and it is the appearance of very long light curves (and therefore time-dilated, compared with the local sample) at very great distances that provided the first cosmic evidence of time dilation. Very long light curves in this and similar 'local' events nullify this evidence of time dilation that was virtually unquestionable less than a decade ago.

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jwj

It's ok not to know. We should try harder to find out.

This supernova had hydrogen in its spectrum, which distinguishes it immediately from the Type Ias used in cosmology.

Also, if true, this type of explosion is very rare -- the only star we know of in our own Galaxy capable of this type of event is Eta Car, and I'm not so sure even it has the oomph to do it. Eta is less than 100 solar masses, and 2006gy appears to have had an ejected mass of 150!

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Phil Plait
The Bad Astronomer
http://www.badastronomy.com
badastro@badastronomy.com

Big ba-da-boom... Ejected mass is 150, what's the estimate on what's still in the remnant? 10?

Seems like the last guestimates I heard on eta carinae was, it was between 1 and 3 stars amount to as much as 150 sm total. That could put it in the realm, maybe. At an estimated 7900 ly, it's probably a neighbor that we'd be better off without.