NASA Hubble Space Telescope Imaging Spectrograph (STIS) views of the rapidly fading visible-light fireball from the most powerful cosmic explosion recorded to date. For a brief moment the light from the blast was equal to the radiance of 100 million billion stars. The initial explosion began as an intense burst of gamma-rays which happened on Jan. 23, 1999.
[Left - Wide view] The blast had already faded to one four-millionth of its original brightness when Hubble made observations on February 8 and 9. The space telescope captured the fading fireball embedded in a galaxy located 2/3 of the way to the horizon of the observable universe.
[Right - Closeup view] Hubble's resolution shows the galaxy is not the classic spiral or elliptical shape. It appears as finger-like filaments extending above the bright white blob of the fireball. The galaxy might be distorted by a collision with another galaxy. This would induce rapid starbirth as gas clouds were heated and compressed, precipitating millions of newborn stars.
The presence of this so-called starburst activity is strongly supported by Hubble and Keck telescope images that show the host galaxy is exceptionally blue. This means it contains a large number of blue newborn stars.
Hubblee's observations further support the idea that these mysterious powerful explosions happen where vigorous star formation takes place. Gamma-ray bursts may be created by the mergers of a pair of neutron stars or black holes, or a hypernova, a theorized type of exceptionally violent exploding star.
Gamma-ray bursts go off at about one per day. The armada of telescopes now looking for them is allowing astronomers to learn more details of the explosion to refine models for explaining these mysterious events.
Credits
Andrew Fruchter (STScI) and NASA| About The Object | |
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| Object Name | GRB 990123 |
| R.A. Position | 15h 25m 30.6s |
| Dec. Position | 44° 46' 0.0" |
| 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 |
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| 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. |
