GRB 241215A
GCN Circular 38573
Subject
GRB 241215A: A long GRB detected by INTEGRAL
Date
2024-12-15T15:02:10Z (6 months ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
Via
Web form
S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report:
a gamma ray burst lasting about 30 s has been detected by IBAS in the IBIS/ISGRI data at 13:53:15 UT of 2024 December 15.
The refined coordinates (J2000) are:
R.A.= 10.5861 deg
DEC.= +32.5190 deg
with an uncertainty of 2.5 arcmin (90% c.l.).
The burst had a peak flux of 0.5 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 4e-7 erg/cmq.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 38574
Subject
GRB 241215A: GROWTH-India telescope optical upper limit
Date
2024-12-15T19:47:09Z (6 months ago)
From
V. Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>
Via
Web form
T. Mohan, A.P. Saikia, V. Swain, R. Kumar, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of the GRB 241215A (Mereghetti et al., GCN 38573) with the 0.7m GROWTH-India Telescope (GIT). Observation started at 2024-12-15T15:27:41 UT, about 1.57 hours after the trigger. We responded to the coordinates reported in GCN notices (trigger No 11001, RA = 10.5810 deg, DEC = 32.4791 deg) and obtained multiple images of 300s in r' filter. With current FOV of 7.5 x 11 arcmin and scale: 0.2 arcsec/pixel, we covered 71 percent of the localization centered around refined coordinates given in GCN 38573.
The obtained upper limit in our stacked image is:
| MJD (mid) | Filter | Exposure (s) | Limiting Magnitude (AB) |
| ----------- | ------ | ------------ | ----------------------- |
| 60659.65319 | r' | 5x300 | 19.9 | |
The upper limit is consistent with Lipunov et el., GCN 38572.
The magnitude is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT, Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular 38575
Subject
GRB 241215A: Montarrenti Observatory optical upper limit
Date
2024-12-15T23:46:31Z (6 months ago)
From
Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it>
Via
Web form
S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez (Montarrenti Observatory, Siena, Italy, part of UAI/SSV-GRB section), M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy) and K. Kalinowski (Aarhus University, Department of Physics and Astronomy) report:
We performed follow-up observations of the field of GRB 241215A with the automated and remoted 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88).
Observations were started at 2024-12-15 17:34:42 UT, 3.83 hours after burst (Mereghetti et al., GCN 38573) stacking 80x40s Rc-band CCD images.
In our preliminary analysis, we have not found any optical transient candidate within the error-box (2.5 arcmin.) of The INTEGRAL Burst Alert System position (RA 00h 42m 20.66s, Dec. +32d 31m 7.68s - J2000) down to the following 3-sigma optical upper limits:
MJD Exp. Filter UL (3-sigma)
60660.2680 80x40s Rc > 20.3
Magnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations. No correction for galactic dust extinction was applied.
The upper limit is consistent with other already reported (Lipunov et al., GCN 38572; Mohan et al., GCN 38574).
GCN Circular 38576
Subject
GRB 241215A: Nanshan/HMT optical upper limit
Date
2024-12-16T01:31:20Z (6 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
X. Liu, S.Q. Jiang, J. An, S.Y. Fu, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report on behalf of a large collaboration:
We observed the field of GRB241215A detected by INTEGRAL/IBIS (Mereghetti et al., GCN 38573) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 2024-12-15T16:09:56.00, i.e., ~ 2.28 hrs after the INTEGRAL trigger and consisted of 15 x 90 s frames without any filter.
No uncatalogued optical source is detected in our stacked images within the INTEGRAL/IBIS 2.5 arcmin error circle (Mereghetti et al., GCN 38573), down to a 3 sigma upper limit of r ~ 19.8, calibrated with nearby Pan-STARRS stars and not corrected for Galactic extinction.
GCN Circular 38580
Subject
GRB 241215A: Mondy AZT-33IK optical observations
Date
2024-12-16T12:34:55Z (5 months ago)
From
Nicolai Pankov at HSE, IKI RAS <colinsergesen@gmail.com>
Via
Web form
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP) report on behalf of IKI-GRB-FuN:
We performed optical observations of the field of GRB 241215A (Mereghetti et. al, GCN 38573; Mohan et. al, GCN 38574; Leonini et. al, GCN 38575; Liu et. al, GCN 38576) in the R filter with AZT-33IK of Sayan (Mondy) observatory. The observations began on 2024-12-15 14:27 UT, i.e. ~1.08 hr since INTEGRAL trigger. We have covered the entire localization area assessed by the INTEGRAL team (Mereghetti et. al, GCN 38573). No candidate transients were found using image subtraction with ```apex_subtract``` pipeline against the PS1 template image. The preliminary upper limit of the stacked image is given below:
| Date | UTstart | t-T0 (mid, days) | Exptime (n*s) | Filter | Magnitude | UL (3sigma) |
| ---------- | -------- | ---------------- | ------------- | ------ | --------- | ----------- |
| 2024-12-15 | 14:27:52 | 0.044875 | 30*120 | R | n/d | 21.3 |
The magnitudes were calibrated using nearby stars from USNO-B1.0 (R2 magnitudes) and are not corrected for the Galactic extinction.