RockDoctor (Slashdot reader #15,477) writes: A recent paper on ArXiv describes a Gamma Ray Burst (GRB) whose light arrived late last year as one of the strongest ever observed. GRB 221009A was detected on October 9 last year (yes, that number is a date), so 5 and a bit months from event to papers published is remarkably quick, and I anticipate that there will be a lot more papers on it in the future. Stand-out points are :
– it lasted for more than ten hours after detection (a space x-ray telescope had time to orbit out of the Earth’s shadow and observe it)
– it could (briefly) be observed by amateur astronomers.
– it is also one of the closest gamma-ray bursts seen and is among the most energetic and luminous bursts.
It’s redshift is given as z= 0.151, which Wikipedia translates as occurring 1.9 billion years ago, at a distance of 2.4 billion light-years from Earth.
Observations have been made of the burst in radio telescopes (many sites, continuing), optical (1 site ; analysis of HST imaging is still in work), ultraviolet (1 space telescope), x-ray (2 space telescopes) and gamma ray (1 sapce telescope) — over a range of 1,000,000,000,000,000-fold (10^15) in wavelength. It’s brightness is such that radio observatories are expected to continue to detect it for “years to come”.
The model of the source is of several (3~10) Earth-masses of material ejected from (whatever, probably a compact body (neutron star or black dwarf) merger) and impacting the interstellar medium at relativistic speeds (Lorentz factor 9, velocity >99.2% of c). The absolute brightness of the burst is high (about 10^43 J) and it is made to seem brighter by being close, and also by the energy being emitted in a narrow jet (“beamed”), which we happen to be near the axis of.
General news sites are starting to notice the reports, including the hilarious acronym of “BOAT — Brightest Of All Time”. Obviously, with observations having only occurred for about 50 years. we’re likely to see something else as bright within the next 50 years.
The brightness of the x-rays from this GRB is such that the x-rays scattered from dust in our galaxy creates halos around the source — which are bright enough to see, and to tell us things about the dust in our galaxy (which is generally very hard to see). Those images are more photogenic than the normal imagery for GRBs — which is nothing — so you’ll see them a lot.
Read more of this story at Slashdot.
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Author Of this post: EditorDavid