Amateur astronomers image a rare glow

A gamma-ray burst reveals its position to observers.
By | Published: February 13, 2014
The optical afterglow of gamma-ray burst 140206A is the magnitude 18 dot marked by the arrow.
Searchlight Observatory Network
Amateur astronomers Arto Oksanen, Petri Kehusmaa, and Caisey Harlingten, on behalf of Searchlight Observatory Network (SON), reported imaging an optical afterglow from a gamma-ray burst (GRB). This marks only the third detection of the optical afterglow of a GRB by amateurs.

The astronomers obtained the data February 6, 2014, at 8h33m09s UT using a 16-inch robotic telescope located at the Rancho Hidalgo Astronomy and Equestrian Village near Animas, New Mexico. They acquired 2-minute images through a red filter.

NASA’s Swift satellite initially reported the 60-second burst, dubbed GRB 140206A, only 44 minutes before the SON telescope imaged the afterglow.

The 2000.0 coordinates of the event are right ascension 9h41m20s and declination 66°45’38”. Those numbers place it in the constellation Ursa Major the Great Bear approximately 2.7° south-southwest of Bode’s Galaxy (M81), a favorite deep-sky target of amateur astronomers.

“Several professional telescopes have imaged the afterglow,” said Petri Kehusmaa. “But we got it first.”

The afterglow shines meagerly at magnitude 18 (measured through a red filter), and it seems to be fading. Other astronomers pegged its visual brightness around magnitude 16. The gamma-ray burst occurred some 11 billion light-years away. Observations and analysis are ongoing.