Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 32679

GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
2022-10-11T10:03:35Z (2 years ago)
Filipp Dmitrievich Romanov at Amateur astronomer <>
I observed the optical afterglow of the extremely bright GRB 221009A =
Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using
telescope T24 (0.61-m f/6.5 reflector + CCD) of iTelescope.Net in
Sierra Remote Observatory (Auberry, California, USA) on 2022-10-11.

Two images (exposures 300 seconds, BINx1) were obtained with Ic
filter, midtime of the stacked image is 06:12:42 UT (1d16h02m after
the trigger).

I clearly detected the afterglow and measured (aperture photometry,
without deblending) following magnitude: 17.1 Ic +/- 0.2 from
comparison to transformed (from Lupton 2005) magnitudes of nearby
stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016).

Magnitude was not corrected for the Galactic extinction.

Stacked image available here:

F. D. Romanov (AAVSO member, observer code: RFDA).
Looking for U.S. government information and services? Visit