[vsnet-grb-info 20025] GRB 171010A: afterglow and SN 2017htp optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22113
SUBJECT: GRB 171010A: afterglow and SN 2017htp optical observations
DATE:    17/11/09 15:51:55 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI),  V. Rumyantsev (CrAO), E. Klunko 
(ISTP),  I. Reva (Fesenkov Astrophysical Institute), A. Kusakin 
(Fesenkov Astrophysical Institute), O. Burhonov (UBAI), A. Volnova (IKI) 
   report on behalf of larger GRB follow-up collaboration:

We observed the field of the Fermi-LAT GRB 171010A (Omodei et al., GCN  
21985) with Zeiss-1000 telescope  (TSHAO), AZT-33IK telescope (Mondy), 
ZTSH2.6m telescope  (CrAO) and AZT-22 telescope  (Maidanak).
Within the enhanced Swift-XRT circle (D'Ai et al., GCN 21989) we clearly 
detect the optical afterglow (Thorstensen & Halpern , GCN 21987; Izzo & 
D. Malesani, GCN 21988; Guidorzi et al., GCN 21991; Malesani et al., GCN 
22000; Harita et al., GCN 22001; Kankare et al., GCN 22002; Breeveld & 
Siegel, GCN 22004; Watson et al., GCN 22011; Kumar et al., GCN 22012).

Still not all data received and we report some preliminary photometry 
of the afterglow in earlier epochs and host+OT in R-filter:

Date       UT_start   t-T0       OT     Err.    Up.Lim.   Telescope
            (mid, days)                          (3 sigma)
2017-10-12 20:11:03  2.11360     19.06  0.04    22.4      Zeiss-1000
2017-10-13 18:34:36  3.00616     19.21  0.05    22.2      AZT-33IK
2017-10-14 18:23:31  3.99492     19.38  0.03    23.1      AZT-33IK
2017-10-15 18:23:04  4.99461     19.35  0.03    23.0      AZT-33IK
2017-10-20 00:57:51  9.26249     19.60  0.03    23.4      ZTSH2.6
2017-10-28 19:42:20 18.04966     19.50  0.06    22.8      AZT-33IK
2017-11-06 19:44:54 27.07226     20.00  0.10    21.4      AZT-22

The photometry is based on nearby USNO-B1.0 stars

USNO-B.1_id     R2
0795-0045061    15.10
0795-0045035    17.25
0795-0045066    16.59

A light curve of the OT+host can be found in 
http://grb.rssi.ru/GRB171010A/GRB171010A_light_curve_R.png

As can be seen from the light curve we can support discovery of  SN 
2017htp (de Ugarte Postigo et al., GCN 22096; Cucchiara et al., GCN 22107).
We will update the LC as more data becomes available.