Other designations GRB 090429B Date 29 April 2009 Constellation Canes Venatici | Event type Gamma-ray burst Duration 5.5±0.1 second | |
 | ||
Instrument Swift Gamma-Ray Burst Mission | ||
GRB 090429B was a gamma-ray burst first detected on 29 April, 2009, by the Burst Alert Telescope aboard the Swift satellite. The burst triggered a standard burst-response observation sequence, which started at 106 s after the burst. The X-ray telescope aboard the satellite identified an uncatalogued fading source. No optical or UV counterpart was seen in the UV–optical telescope. Around 2.5 hours after the burst trigger, a series of observations was carried out from Gemini North, which detected a bright object in the infrared part of the spectrum. No evidence of a host galaxy was found either by Gemini North or by HST. Though this burst was detected in 2009, it was not until May 2011 that its distance estimate was announced. The burst had a photometric redshift of z=9.4, which would make it the most distant GRB known, although the error bar on this estimate was large, providing a lower limit of z>7.
The amount of energy, released in the burst, was estimated as 3.5 × 1052 erg. For a comparison, the Sun's luminosity is 3.8 × 1033 erg/s.
On 2009 April 29, a five-second-long burst of gamma rays from the constellation Canes Venatici triggered the Burst Alert Telescope on NASA's Swift satellite.