An intriguing chain of events has been detected on February 6, 20205:
It all started with S250206dm, a gravitational wave detected by both LIGO interferometers. It has rapidly been classified as being either a merger of a neutron star with a black hole (55% probability) or a merger of a binary neutron start system (37%). There remains a roughly 8% probability that the event was due to noise background. The event has been fairly well localized (910 deg² at 90% containement) and is not too far way at 348 ± 114 Mpc .
A scan of the probable sky region in various wavelength has started to search a counterpart.
Last night I tried to observe this event targetting one of the tile given by AstroColibri during 45mn reaching mag 20.5 (19.9 at SNR=5). Unfortunately, I have no tool to compare automatically the resutling image and more, this tile position does not coincide to one of the new target list given by GCN 39206 (see : GCN Circular 39206).
Covering these large uncertainty regions is indeed challenging!
In addition, the localisation region provided by the gravitational wave observatories has been updated several times yesterday evening/night, as soon as new analysis results became available. You can reproduce these changes by going through the archive within Astro-COLIBRI:
Improved analyses of the gravitational wave data have led to significant shifts and reductions of the localisation region derived from that data. The best-fit neutrino position given as S250206dm_NuTracks seems now no longer compatible with the GW region.
It could well be that this was a chance coincidence after all…
