Astronomers previously have detected stars disrupted by supermassive black holes, but none have shown the X-ray brightness and variability seen in GRB 110328A. The source has undergone numerous flares. Since Sunday, April 3, for example, it has brightened by more than five times. Scientists think the X-rays may be coming from matter moving near the speed of light in a particle jet that forms along the rotation axis of the spinning black hole as the star's gas falls into a disk around the black hole. Read more
Title: Enhanced emission from GRB 110328A could be evidence for tidal disruption of a star Authors: Ulisses Barres de Almeida, Alessandro De Angelis
On March 28, Swift's Burst Alert Telescope discovered a source in the constellation Draco when it erupted in a series of X-ray blasts. The explosion, catalogued as gamma-ray burst (GRB) 110328A, repeatedly flared in the following days, making the interpretation of the event as a GRB unlikely. Here we suggest that the event could be due to the tidal disruption of a star that approaches the pericentric distance of a black hole, and we use this fact to derive bounds on the physical characteristics of such system, based on the variability timescales and energetics of the observed X-ray emission.
NASA Telescopes Join Forces to Observe Unprecedented Explosion
NASA's Swift satellite, Hubble Space Telescope, and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts ever observed. More than a week later, high-energy radiation continues to brighten and fade from its location. Astronomers say they have never seen such a bright, variable, high-energy, long-lasting burst before. Usually, gamma-ray bursts mark the destruction of a massive star, and flaring emission from these events never lasts more than a few hours. Read more
Position (J2000): R.A. 16h 44m 49s.3, Dec. +57° 34' 51"
NASA Telescopes Join Forces to Observe Unprecedented Explosion
NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location. Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours. Read more
The center of this image contains an extraordinary gamma-ray burst (GRB) called GRB 110328A, observed with NASA's Chandra X-ray Observatory. This Chandra observation confirms the association of GRB 110328A with the core of a distant galaxy and shows that it was an exceptionally long lived and luminous event compared to other GRBs.