National Radio Astronomy Observatory | VLA | 2018 Oct 04
Astronomers comparing data from an ongoing major survey of the sky using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to data from earlier surveys likely have made the first discovery of the afterglow of a powerful gamma ray burst that produced no gamma rays detectable at Earth. The unprecedented discovery of this “orphan” gamma ray burst (GRB) offers key clues to understanding the aftermath of these highly energetic events. ...
While searching through data from the first epoch of observing for the VLA Sky Survey (VLASS) in late 2017, the astronomers noted that an object that appeared in images from an earlier VLA survey in 1994 did not appear in the VLASS images. They then searched for additional data from the VLA and other radio telescopes. They found that observations of the object’s location in the sky dating back as far as 1975 had not detected it until it first appeared in a VLA image from 1993.
The object then appeared in several images made with the VLA and the Westerbork telescope in the Netherlands from 1993 through 2015. The object, dubbed FIRST J1419+3940, is in the outskirts of a galaxy more than 280 million light-years from Earth. ...
Ghost Objects in the Sky
University of California, Berkeley | 2018 Oct 04
Astronomers Discover Sonic Boom From Powerful Unseen Explosion
Dunlap Institute for Astronomy & Astrophysics | University of Toronto | 2018 Oct 04
Discovery of the Luminous, Decades-Long, Extragalactic Radio Transient FIRST J141918.9+394036 ~ C.J. Law et al
- arXiv.org > astro-ph > arXiv:1808.08964 > 27 Aug 2018