* Astronomy

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RE: SCP 06F6

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Brightest supernovae are in a class of their own

Some of the brightest stellar explosions in the Universe should be classified together as a new type of supernova, according to an international collaboration of researchers. The group has catalogued six explosions that cannot easily be explained by any process yet known.
The supernovae in the new class have several distinguishing features. One is that they are very bright - about ten times more luminous than type Ia supernovae, the most commonly recorded type. Another is that their main emission is not visible light, as for most supernovae, but ultraviolet radiation.
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Optical transient phenomena

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SCP06F6

Blobrana · L

RE: SCP 06F6

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Title: Discovery of an Unusual Optical Transient with the Hubble Space Telescope
Authors: K. Barbary, K. S. Dawson, K. Tokita, G. Aldering, R. Amanullah, N. V. Connolly, M. Doi, L. Faccioli, V. Fadeyev, A. S. Fruchter, G. Goldhaber, A. Goobar, A. Gude, X. Huang, Y. Ihara, K. Konishi, M. Kowalski, C. Lidman, J. Meyers, T. Morokuma, P. Nugent, S. Perlmutter, D. Rubin, D. Schlegel, A. L. Spadafora, N. Suzuki, H. K. Swift, N. Takanashi, R. C. Thomas, N. Yasuda, for the Supernova Cosmology Project
(10 Sep 2008)

We present observations of SCP 06F6, an unusual optical transient discovered during the Hubble Space Telescope Cluster Supernova Survey. The transient brightened over a period of ~100 days, reached a peak magnitude of ~21.0 in both i_775 and z_850, and then declined over a similar timescale. There is no host galaxy or progenitor star detected at the location of the transient to a 3 sigma upper limit of i_775 = 26.4 and z_850 = 26.1, giving a corresponding lower limit on the flux increase of a factor of ~120. Multiple spectra show five broad absorption bands between 4100 AA and 6500 AA and a mostly featureless continuum longward of 6500 AA. The shape of the lightcurve is inconsistent with microlensing. The transient's spectrum, in addition to being inconsistent with all known supernova types, is not matched to any spectrum in the Sloan Digital Sky Survey (SDSS) database. We suggest that the transient may be one of a new class.

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Blobrana · L

A wandering black hole may have torn apart a star to create a strange object that brightened mysteriously and then faded from view in 2006, a new study suggests. But more than three years later, astronomers are still at a loss to explain all the features of the strange event.
The object, called SCP 06F6, was first spotted in the constellation Bootes in February 2006 in a search for supernovae by the Hubble Space Telescope. The object flared to its maximum brightness over about 100 days, a period much longer than most supernovae, which do so in just 20 days.

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Stellar Explosion Displays Massive Carbon Footprint
While humans are still struggling to get rid of unwanted carbon it appears that the heavens are really rather good at it. New research by astrophysicists at the University of Warwick has discovered that a mystery stellar explosion recorded in 2006 may have marked the unusual death of an equally unusually carbon-rich star.
The strange object known as SCP 06F6 was first noted in 2006 by supernovae researchers in the US taking images with the Hubble Space Telescope, seeing it appearing out of nowhere, and fading again into oblivion, over the course of 120 days. The US team published their observations in September 2008, drawing a blank on the nature of SCP 06F6, in particular it was unclear if this event happened in our cosmic backyard, or at the other end of the universe.
Now a team of astrophysicists and astronomers at the University of Warwick in the UK believe they have come up with an answer. According to their research, the observations of SCP 06F6 bear remarkable resemblance to a group of stars containing extremely large proportions of carbon, hence dubbed carbon stars. However, to achieve the close match, SCP 06F6 must be at a distance of around 2 billion light years, causing a considerable redshift in its appearance. Given the large distance, the sudden appearance of SCP 06F6 is most likely related to the sudden death of a carbon-rich star, and the Warwick team believes that this object may be a new type of a totally new class of supernova.

Source

Blobrana · L

Almost three years ago, astronomers using the Hubble Space Telescope were perusing a cluster of galaxies about eight billion light-years from Earth when they came upon a flash of light unlike anything they had seen before.
Over the next 100 days, the object gradually brightened. Then it spent another 100 days growing dimmer, until it finally vanished from view.
Astronomers speaking last week at the American Astronomical Society meeting in Long Beach, California, still have no idea what it was - or is.

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Blobrana · L

A mysterious flash of light from somewhere near or far in the universe is still keeping astronomers in the dark long after it was first detected by NASA's Hubble Space Telescope in 2006. It might represent an entirely new class of stellar phenomena that has previously gone undetected in the universe, say researchers.
Astronomers commonly observe intense flashes of light from a variety of stellar explosions and outbursts, such as novae and supernovae. Hubble discovered the cosmic flash on February 21, 2006. It steadily rose in brightness for 100 days, and then dimmed back to oblivion after another 100 days.
The rise and fall in brightness has a signature that simply has never been recorded for any other type of celestial event. Supernovae peak after no more than 70 days, and gravitational lensing events are much shorter. Therefore, this observation defies a simple explanation.
The spectral fingerprints of light coming from the object, catalogued as SCP 06F6, also have eluded identification as being due to any specific element. One guess is that the features are redshifted molecular carbon absorption lines in a star roughly one billion light-years away.
But searches through various astronomical survey catalogues for the source of the light have not uncovered any evidence for a star or galaxy at the location of the flash. The Supernova Cosmology Project at LBNL discovered it serendipitously in a search for supernovae.

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