Peering across 7.5 billion light-years and halfway back to the Big Bang, NASA's Hubble Space Telescope has photographed the fading optical counterpart of a powerful gamma ray burst that holds the record for being the intrinsically brightest naked-eye object ever seen from Earth. For nearly a minute this single star was as bright as 10 million galaxies.
Hubble Wide Field and Planetary Camera 2 (WFPC2) images of GRB 080319B, taken on Monday, April 7, show the fading optical counterpart of the titanic blast. The object erupted in a brilliant flash of gamma rays and other electromagnetic radiation at 2:12 a.m. EDT on March 19, and was detected by Swift, NASA's gamma ray burst watchdog satellite. Immediately after the explosion, the gamma ray burst glowed as a dim 5th magnitude "star" in the spring constellation Bootes. Designated GRB 080319B, the intergalactic firework has been fading away ever since then. Hubble astronomers had hoped to see the host galaxy where the burst presumably originated, but were taken aback that the light from the GRB is still drowning out the galaxy's light even three weeks after the explosion. This is particularly surprising because it was such a bright GRB initially.
Previously, bright bursts have tended to fade more rapidly, which fits in to the theory that brighter GRBs emit their energy in a more tightly confined beam. The slow fading leaves astronomers puzzling about just where the energy came from to power this GRB, and makes Hubble's next observations of this object in May all the more crucial. Called a long-duration gamma ray burst, such events are theorized to be caused by the death of a very massive star, perhaps weighing as much as 50 times our Sun. Such explosions, sometimes dubbed "hypernovae," are more powerful than ordinary supernova explosions and are far more luminous, in part because their energy seems to be concentrated into a blowtorch-like beam that, in this case, was aimed directly at Earth. The Hubble exposure also shows field galaxies around the fading optical component of the gamma ray burst, which are probably unrelated to the burst itself.
Credits
NASA, ESA, N. Tanvir (University of Leicester), and A. Fruchter (STScI)| About The Object | |
|---|---|
| Object Name | GRB 080319B |
| Object Description | Gamma Ray Burst |
| R.A. Position | 14h 31m 40.99s |
| Dec. Position | 36° 18' 9.0" |
| Constellation | Boötes |
| Distance | 7.5 billion light-years or 2.3 billion parsecs |
| Dimensions | This image is 25 arcseconds (91,000 light-years or 28,000 parsecs) square. |
| About The Data | |
| Data Description | HST Proposal: N. Tanvir, K. Wiersma, and E. Rol (University of Leicester), A. Fruchter (STScI), and A. Levan (University of Warwick). |
| Instrument | HST>WFPC2 |
| Exposure Dates | April 7, 2008, Exposure Time: 1.8 hours |
| Filters | F606W (V) and F814W (I) |
| About The Image | |
| Color Info | The image is a composite of several separate exposures made by the WFPC2 instrument on the Hubble Space Telescope. Two filters were used to sample broad wavelength ranges in the yellow and near infrafed. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Blue: F814W (I) Orange: F606W (V) |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
