GRB 090429B

GRB 090429B

Event type	Gamma-ray burst
Constellation	Canes Venatici
Right ascension	14h 02m 40.10s
Declination	+32° 10′ 14.6″
Total energy output	3.5 × 1052 erg
Other designations	GRB 090429B
[edit on Wikidata]

GRB 090429B was a gamma-ray burst observed on 29 April 2009 by the Burst Alert Telescope aboard the Swift satellite. The burst triggered a standard burst-response observation sequence, which started 106 seconds after the burst.^[1] 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 by the Gemini North telescope, 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 the Hubble Space Telescope.^[1] Though this burst was detected in 2009, it was not until May 2011 that its distance estimate of 13.14 billion light-years was announced. With 90% likelihood, the burst had a photometric redshift greater than z = 9.06, which would make it the most distant GRB known, although the error bar on this estimate is large, providing a lower limit of z > 7.^[1][2]

The amount of energy released in the burst was estimated at 3.5 × 10⁵² erg. For a comparison, the Sun's luminosity is 3.8 × 10³³ erg/s.^{[citation needed]}