GCN Circular 24751
Subject
GRB 190530A: optical follow-up observations at Konkoly
Event
Date
2019-06-05T13:27:40Z (6 years ago)
From
Jozsef Vinko at Konkoly Observatory <vinko@konkoly.hu>
J. Vinko, R. Szakats, A. Pal, L. Kriskovics, A. Ordasi, K. Sarneczky
(MTA CSFK Konkoly Observatory) report:
We took follow-up observations on the optical afterglow (Lipunov et al., GCN 24680;
Kann et al., GCN 24684; Heintz et al., GCN 24686; Izzo et al., GCN 24687;
Xin et al., GCN 24688; Watson et al., GCN 24690; Lipunov et al., GCN 24693;
Xin et al., GCN 24697; Belkin et al., GCN 24698; Kann et al., GCN 24700;
Siegel, GCN 24703; Moskvitin and Uklein, GCN 24708; Vinko et al., GCN 24709;
Belkin et al., GCN 24712; Kumar et al., GCN 24729; Nandi et al., GCN 24745)
of the bright GRB 190530A (Fermi GBM team, GCN 24676, Biltzinger et al., GCN 24677;
Longo et al., GCN 24679; Lucarelli et al.,GCN 24678, Verecchia et al., GCN 24683).
The source was clearly detected on the stacked Sloan-r band CCD frames (total exposure time 60 min)
taken with the 0.8m RC80 telescope at Konkoly Observatory, Piszkesteto (Hungary)
on 2019-06-01.85 UT, but only marginally detected on the frames taken
on 2019-06-02.86 UT (2.42 and 3.43 days after burst, respectively).
We measured the brightness of the transient via aperture photometry on the stacked
r-band frames using PS1 r-band magnitudes of 19 local comparison stars. The results,
corrected for the contamination of the nearby faint source (r_PS1(AB) = 20.947 +/- 0.0565 mag),
are as follows:
# Date UT(mid) JD-2400000 r(AB) unc. Ref
#----------------------------------------------------------------
2019-05-31 20:23:35 58635.349711 20.36 0.37 GCN 24709
2019-06-01 20:23:56 58636.349953 20.15 0.11 this circular
2019-06-02 20:37:30 58637.359375 22.10 0.41 this circular
#----------------------------------------------------------------
Note that in Vinko et al. (GCN 24709) the UT date of the observation was
reported incorrectly. The correct date was 2019-05-31.85 UT. Also, our
previous photometry given in GCN 24709 was not corrected for the nearby
contaminating source. The table above contains the updated, corrected
magnitudes.
Our last photometric measurement (taken on 2019-06-02) is consistent with the
R-band magnitude reported by Kumar et al. (GCN 24729, R ~ 21.3 +/- 0.3 mag).