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GCN Circular 32939

GRB 221110A: GRANDMA observations
2022-11-15T13:57:43Z (2 years ago)
Iara Tosta e Melo at INFN <>
M. Coughlin (UMN), E. Gurbanov (ShAO), F. Navarete (SOAR/NOIRLab),
N. Kochiashvili (AbAO), M. Masek (FZU), Y. Rajabov (UBAI),
T. Sadibekova (AIM-CEA), M. Freeberg (KNC), A. Klotz (OMP/IRAP),
M. Boer, A. de Ugarte Postigo, S. Antier (OCA/Artemis), D. Turpin (CEA),
R.W. Kiendrebeogo (OCA/Artemis, LPCE/UJKZ), I. Tosta e Melo (INFN-LNS),
M. Lamoureux, K. Kruiswijk (UCLouvain), J.-G. Ducoin (IAP),
C. Rinner, Z. Benkhaldoun (OUCA), J. Ali, A. Kaouech (OUCA/KNC),
A. M. Fouad, A. Takey, A. Hamed, M. Abdel-Sabour, A. Shokry,
M. Soliman (NRIAG),  X. F. Wang (THU/BJP), J. Zhu (BJP), X. Y. Zeng 
L. T. Wang, A. Iskandar (XAO), K. Smith (UVI), P. Gokuldass (Florida 
N. Orange (OrangeWave Innovative Science, LLC), T. Hussenot (IJCLab),
A. M. Fouad (NRIAG), A. Takey(NRIAG), H. A. Ismail, M. Abdel-Sabour 
D. A. Kann (Goethe Univ.) report on behalf of the GRANDMA collaboration:

The GRANDMA telescope network responded to the Swift-BAT alert of
GRB 221110A (M. A. Williams et al., GCN 32925, P.A. Evans et al. GCN 
detected at 02:28:17.62 UT. An afterglow was immediately detected by 
UVOT with
the estimated magnitude of 18.62 with a 1-sigma error of ~0.07 at XRT
(not refined) position RA, Dec: 29.09928, -27.29435. The VLT/X-shooter
spectroscopic observations (L. Izzo et al., GCN 32928) reported a high-z
candidate at z=4.06.

The first GRANDMA observations started 40 s after the BAT trigger time
with TCH telescope at La Silla, Chile.

Below, we report selected observations. We also report our 5-sigma upper
limits. Magnitudes are given in the AB system.

T-T0(hr)|    MJD     | Obser.  | Exposure | Filter | Mag +/- err|Upp.Lim
  0.06   |59893.105660| TCH     | 5x30s    |  clear | 15.9+/-0.1 | 17.2
  3.3    |59893.242788| SOAR    | 1x300s   |  sdssr | 21.7+/-0.2 | -
  3.3    |59893.246601| SOAR    | 1x300s   |  sdssi | 19.8+/-0.1 | -
  3.3    |59893.238496| SOAR    | 1x300s   |  sdssz | 19.4+/-0.2 | -
  8.1    |59893.440510| KNC-SSO | 5x300s   |   Ic   |       -    | 19.0
  17.6   |59893.835694| KAO     | 10x250s  | sdssz  |       -    | 19.9
  18.7   |59893.881065| KNC-HAO | 20x180s  |    R   |       -    | 19.8
  19.3   |59893.905405| MOSS    | 60x60s   |  clear |       -    | 20.4
  25.1   |59894.149306| VIRT    | 400x10s  |    R   |       -    | 20.1

These observations are consistent with previous reports by LCOGT
(R. Strausbaugh et al GCN 32926) and COATLI (M. Pereyra et al. GCN 

TCH and MOSS data have been calibrated using nearby
stars from the Pan-STARRS catalogue in sdss-r measured with
STDpipe (Karpov 2022).

KNC-HAO data have been calibrated with respect to
field stars from the Pan-STARRS and APASS catalogues, using the MUPHOTEN
pipeline (Duverne et al. 2022).

The upper limit derived for KAO data was defined with the faintest 
star in the field and the images were processed with IRAF.

SOAR used the "Goodman Spectroscopic Pipeline" for imaging processing
and IRAF for getting the astrometric solution. The photometric 
was done by comparison with SkyMapper sources in the field in SDSS.

The images of iTelescope 32 (Siding Spring Observatory, Australia)
have been processed using the STDpipe and photometry was performed
using field stars from the PanSTARRS1-i catalogue as a reference.

VIRT data was processed with the in-house pipeline which uses the
USNO.B1 catalogue.

The nearly full Moon contaminated the observations.

GRANDMA is a worldwide telescope network (
devoted to the observation of transients in the context of 
astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher 
(KNC) is
the citizen science program of GRANDMA 
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