SN 2011fe

SN 2011fe

Supernova event on August 25, 2011
Other designations	SN 2011fe
Event type	Supernova
Spectral class	Ia
Observation
Date	24 August 2011
Location
Constellation	Ursa Major, Big Dipper
Right ascension	14h 03m 05.8s
Declination	+54° 16′ 25″
Epoch	J2000
Distance	21 Mly
Host	Pinwheel Galaxy (M101)
Characteristics
Energetics
Peak apparent magnitude	9.9
See also
[]

SN 2011fe, initially designated PTF 11kly, was a Type Ia supernova discovered by the Palomar Transient Factory (PTF) survey on 24 August 2011 during an automated review of images of the Messier 101 from the nights of 22 and 23 August 2011. It was located in Messier 101, the Pinwheel Galaxy, 21 million light years from Earth. It was observed by the PTF survey very near the beginning of its supernova event, when it was approximately 1 million times too dim to be visible to the naked eye. It is the youngest type Ia ever discovered. About 13 September 2011, it reached its maximum brightness of apparent magnitude +9.9 which equals an absolute magnitude of about -19, equal to 2.5 billion Suns. At +10 apparent magnitude around 5 September, SN 2011fe was visible in small telescopes. As of 30 September the supernova was at +11 apparent magnitude in the early evening sky after sunset above the northwest horizon. It had dropped to +13.7 as of 26 November 2011.

The Palomar Transient Factory is an automated telescopic survey that scans the sky for transient and variable astronomical events. Information is fed to the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Lab, which computes the information to identify new star events. After the initial observation of the SN 2011fe event, telescopes were used in the Canary Islands (Spain) to identify the emission spectrum of light emitted at various stages of the event. Following this, the Hubble Space Telescope, the Lick Observatory in California, and the Keck Observatory in Hawaii were used to observe the event in greater detail.