GCN Circular 32659
Subject
GRB 221009A: Multi-color detection of the optical
Event
Date
2022-10-10T14:16:00Z (4 years ago)
From
Gregory SungHak Paek at SNU <shpaek@astro.snu.ac.kr>
Gregory S.H. Paek (SNU ARC/SNU), Myungshin Im (SNU ARC/SNU), Yuji Urata
(NCU), Hyun-Il Sung (KASI) on behalf of a larger collaboration
We detected the optical counterpart/NIR afterglow of extremely bright GRB
221009A (Dichiara et al., GCN #32632) with the 1-m class telescopes in
Lemonsan Optical Astronomy Observatory (LOAO) facilities of the GW
EM-Counterpart Korean Observatory (GECKO).
We observed the center of UVOT localization (RA, Dec = 288.265, +19.774)
+15 hours after the report in B, V, R, I, z, and Y-bands. We clearly
detected the afterglow in all V, R, I, z, and Y-bands except for the
B-band. We calibrated flux with the PANSTARRS catalog and used an AB
magnitude system. Depth means 5 sigma upper limit for a point source
detection. The magnitudes are not corrected for galactic extinction.
------------------- ----------- ----------- ------ ----------- ----------
----- ------ -----
DATE-OBS[UTC] JD t-t0[days] FILTER Observatory EXPTIME[s]
MAG MAGERR DEPTH
------------------- ----------- ----------- ------ ----------- ----------
----- ------ -----
2022-10-10T04:18:54 2459862.680 0.626 B LOAO 60s*5
None None 19.66
2022-10-10T04:20:38 2459862.681 0.628 V LOAO 60s*5
18.74 0.13 19.48
2022-10-10T04:22:04 2459862.682 0.629 R LOAO 60s*5
17.55 0.06 19.75
2022-10-10T04:23:31 2459862.683 0.630 I LOAO 60s*5
16.41 0.05 19.56
2022-10-10T04:24:39 2459862.684 0.631 z LOAO 60s*5
TBD TBD TBD
2022-10-10T04:25:58 2459862.685 0.631 Y LOAO 60s*5
TBD TBD TBD
We will continue the follow-up observation for this target with the LOAO,
and other GECKO facilities in Australia, and Chile. Gravitational-wave EM
Counterpart Korean Observatory (GECKO) is a network of 10+ 0.5m to 1m class
telescopes worldwide.