GCN Circular 42370
Subject
GRB 251017A : RAPAS follow-up observations
Event
Date
2025-10-19T21:33:07Z (2 days ago)
From
Thierry Midavaine at SAF - RAPAS <thierrymidavaine@sfr.fr>
Via
Web form
Thierry Midavaine on behalf of the RAPAS network reports (#5) :
Pascal André, David Fardin, Patrick Martinez [1], Christian Pantacchini [2], Jean-Marie Lopez, Cyril Cavadore [3], Lisa Maris [4] observed the field of Gamma-Ray Burst GRB 251017A (R. Gupta et al. GCN 42322, I. Perez-Garcia GCN 42323) using :
[1] ADAGIO N 820mm telescope f=3.1m at Belesta Observatory (IAU A05) equipped with a Moravian C3 CMOS camera,
[2] N308 mm telescope f=1.1m equipped with a Moravian g3 KAI11000 CCD camera,
[3] Société Astronomique de Montpellier N 500mm telescope f=2.2m at Observatoire des Pises (IAU 122) equipped with an ASI6200MMPro CMOS camera,
[4] SC 280mm f=1.8m equipped with an ATIK4000 CCD camera.
[1][2][3][4] are equipped with RAPAS filters meeting the Gaia G, Gbp, Grp photometric bands. The FITS files are reduced with the Gaia photometric catalog in respective G, Gbp and Grp bands.
The afterglow is detected at
RA(J2000) = 22h 21m 36.22s ; Dec(J2000) = +07° 02’ 23.6” ; ± 0.5’’ in G and Grp bands [1]
RA(J2000) = 22h 21m 36.956s; Dec(J2000) = +07° 02’ 21.90” in G band [3]
At this RA Dec location the GRB is above the respective upper limit magnitude Gbp for [1], G for [2] and [4], Gbp and Grp for [3]
MJD (mid) Gaia band exp(s) mag.(Gaia) upperlim RAPAS station
60965.81618 G 1200 22.5 ± 0.3 [3]
60965.82986 G 4500 20.24 [4]
60965.83819 G 3600 22.0 ± 0.3 [1]
60965.83819 Gbp 600 21 [1]
60965.83819 Grp 600 >20.00 [1]
60965.89722 G [2]
Acknowledgements :
RAPAS ( https://gemini.obspm.fr/20220101-rapas/ ) is a ProAm collaboration created by T. Midavaine (SAF), W. Thuillot (LTE, Obs. de Paris-PSL) and M. Dennefeld (IAP/CNRS and Sorbonne Univ.) and funded by the Paris Observatory under API ProAm of the Scientific Council. It aims at homogenizing observing procedures and filters, and is delivering to a network of french amateur observatories a set of 3 filters which have been chosen to meet the Gaia G, Gbp and Grp spectral bands. This network produces data on astrophysical alerts delivered by various Alert systems (Gaia Alerts, Atlas, ZTF, etc…) and collected by Astro-COLIBRI ( https://astro-colibri.science ). This network is similarly progressing towards an homogeneous spectroscopic equipment to deliver SED.