TITLE: GCN CIRCULAR
NUMBER: 39355
SUBJECT: LIGO/Virgo/KAGRA S250206dm: observation in AbAO, optical transient near NED/GLADE+ galaxy WISEA J021210.14+514821.7
DATE: 25/02/17 20:20:56 GMT
FROM: Alexei Pozanenko at IKI, Moscow <grb.alex(a)gmail.com>
A. Pozanenko (IKI, HSE), A. Volnova (IKI), N. Pankov (HSE, IKI), R. Ya.
Inasaridze (AbAO) report on behalf of IKI GRB-FuN collaboration:
We continue to observe galaxies from the NED/GLADE+ catalogs in the
localization volume …
[View More]S250206dm (LIGO Scientific Collaboration, GCN 39175;
LIGO Scientific Collaboration, GCN 39184).
We observed several galaxies with AS-32 telescope of the Abastumani
Observatory (AbAO) in the R-filter. The observations consist of 3 exposures
in R-filter of each galaxy in the on Feb., 12 and Feb. 16. In the first
epoch of observations near the galaxy WISEA J021210.14+514821.7 we clearly
detected an optical source which is not present in the PS1 catalog. The
source is visible in each of the 3 exposures. The source is not detected in
the following epoch on February 16. Preliminary photometry of stacked
images is the following
Date |UTstart |t-T0* |MJD_mid |Exp. |Filter|OT |Err |UL |FWHM
| |(mid, days)| |(n*s) | | | |(3sigma)|"
----------------------------------------------------------------------------
2025-02-12|15:46:10| 5.76573|60718.65844| 3*60 |R |18.15|0.21|19.0 |3.1
2025-02-16|15:57:48| 9.77361|60722.66632| 3*60 |R | n/d |n/d |19.1 |3.0
* - T0 = 21:25:30.439 UTC LIGO trigger time of S250206dm
Photometry is based on nearby stars from USNO-B1.0:
ID RA Dec R2
1418-00067499 02:12:12.126 +51:49:52.59 14.68
1418-00067498 02:12:12.025 +51:48:41.88 14.94
1418-00067549 02:12:18.069 +51:48:21.33 13.93
The source coordinates are (J2000) 02:12:10.17 +51:48:21.54, and the offset
from the center of the galaxy is 6.2", which is equivalent to 11 kpc at a
luminosity distance of DL = 457 Mpc (GLADE+).
We have not observed this galaxy before, so we cannot say anything about
the nature of this source and further observations and analysis of further
observations of this galaxy are needed.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39355.
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TITLE: GCN CIRCULAR
NUMBER: 39353
SUBJECT: GRANDMA/OPD observations of GRB250215A
DATE: 25/02/17 12:20:03 GMT
FROM: Nidhal Guessoum at AUS, UAE <nguessoum(a)aus.edu>
Leandro de Almeida (LNA), Nélio Sasaki (UEA-Parintins), Wagner Corradi (LNA), Felipe Navarete (LNA), Martin Masek (FZU), Nuha Manal Pattani (AUS), Shaikha Alshamsi (AUS), S. Antier (OCA/IJCLAB), P. Hello (IJCLAB), N. Guessoum (AUS), C. Andrade, M. Coughlin (UMN), P-A Duverne (APC), S. Karpov (FZU), T. Pradier (…
[View More]Unistra/IPHC), and D. Turpin (CEA-Saclay/Irfu), on behalf of Observatório do Pico dos Dias (OPD/LNA/Brazil) and the GRANDMA collaboration, began observations of GRB 250215A, initially detected by the Fermi GBM Team (GCN 39327).
Based on the coordinates of the field center (RA=10:25:19.48, DEC=-27:41:54.00), we obtained 12 frames of 300 seconds each using the 0.6m telescope of OPD, starting on 2025-02-16 at 02:30:42.23 and ending at 07:43:29.39 UTC. The FOV of the stacked image is 10.5x10.5 arcmin with a pixel scale of 0.614 arcsec/pixel.
We did not detect any candidate in our stacked images with an upper limit of I > 21.34 mag at 5-sigma, calibrated against several stars of the I/339 catalog (HSOY, Altmann et al, 2017).
Our non-detection upper limit is similar to the results of Ducoin et al. (GCN 39344) with nothing brighter than 22.7 mag detected in r. Our results are also in slight discrepancy with the findings of Malesani et al. (GCN 39341).
GRANDMA is a worldwide telescope network (http://grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518).
View this GCN Circular online at https://gcn.nasa.gov/circulars/39353.
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TITLE: GCN CIRCULAR
NUMBER: 39351
SUBJECT: The EP-WXT trigger 01709131775 is likely a flaring star
DATE: 25/02/17 08:09:25 GMT
FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn>
C. Zhou (HUST), G. Y. Zhao (SYSU), T. C. Zheng (PMO, CAS), X. Pan, H. W. Pan (NAOC, CAS) report on behalf of the Einstein Probe team:
The EP-WXT trigger (ID: 01709131775 ) on 2025-02-17 06:56:23 (UTC) is likely a stellar flare associated with a T Tauri star RX J0523.0-0850. The estimated flux of the flare is …
[View More]around 8.0 x 10^-11 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 2.2 x 10^32 erg/s.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with onboard X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).
View this GCN Circular online at https://gcn.nasa.gov/circulars/39351.
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TITLE: GCN CIRCULAR
NUMBER: 39348
SUBJECT: GRB 250215A / EP250215a: LCO detection of the afterglow
DATE: 25/02/16 21:11:38 GMT
FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es>
I. Pérez-Fournon, F. Poidevin, D. Aguado, J.A. Acosta-Pulido, A. López-Oramas, D. Nespral (IAC and ULL), F. Acero (CEA Saclay and IAC), N.C. Sun (UCAS), W. Li, Y. Wang, Z. Niu (NAOC), D. Cano-Morales, I. Correa-Plasencia, and A.E. Hernández-Díaz (ULL)
We observed the field …
[View More]of the Fermi long GRB 250215A (Fermi GBM Team, GCN Circ. 39327), detected also by Einstein Probe WXT and FXT (EP250215a, Wang et al., GCN Circ. 39329), INTEGRAL SPI-ACS (Barria et al., GCN Circ. 39331), AstroSat CZTI (Tembhurnikar et al., GCN Circ. 39334), SVOM/GRM (Zheng et al., GCN Circ. 39335), and Swift XRT (Page et al., GCN Circ. 39336) with the two Las Cumbres Observatory Global Telescope network (LCOGT) 1-m telescopes, equipped with Sinistro cameras, at the LCOGT node at the Siding Spring Observatory (Australia). We obtained two 600-sec exposures in the SDDS-i' filter starting at 2025-02-15 11:08:48 and 12:58:59 UT, respectively. The optical afterglow detected first by Liu et al. (GCN Circ. 39330) at a redshift of z = 4.61 (Sánchez-Ramírez et al., GCN Circ. 39343)
is clearly detected in our LCOGT images with magnitudes of i' = 20.10 +/- 0.15 in the first observation (starting 8.615 after the trigger) and i' = 20.59 +/- 0.23 in the second one (starting 10.451 hr after trigger), with a clear fading between the two observations. The photometry has been
calibrated against Pan-STARRS DR2 and is not corrected for Galactic extinction. These results are consistent with other optical detections of the afterglow (Liu et al., GCN Circ. 39330; Xie et al., GCN Circ. 39333; Malesani et al., GCN Circ. 39339; and Malesani et al. GCN Circ. 39341).
This work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT observing programme IAC2025A-009, SGLF).
View this GCN Circular online at https://gcn.nasa.gov/circulars/39348.
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TITLE: GCN CIRCULAR
NUMBER: 39346
SUBJECT: EP250212a: FTW optical and NIR upper limits
DATE: 25/02/16 19:03:45 GMT
FROM: Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann(a)physik.lmu.de>
Malte Busmann (LMU), Brendan O’Connor (Carnegie Mellon U.), Daniel Gruen (LMU) and Antonella Palmese (Carnegie Mellon U.) report:
We observed the EP-FXT localization area of EP250212a (Li et al., GCN 39308) with the Three Channel Imager (3KK) at the Fraunhofer Telescope at …
[View More]Wendelstein Observatory (FTW) in the r, i and J band simultaneously for 18 x 180 s starting at 2025-02-15T23:51:26 UT (3.67 days after the WXT trigger). Earlier observations were not possible due to bad weather. Consistent with Malesani et al. (GCN 39306), Eyles-Ferris et al. (GCN 39309) and Junjie-Jin et al. (GCN 39319) we detect no source at a 3 sigma depth of
r > 23.3 mag
i > 23.0 mag
J > 22.0 mag.
The r- and i-band magnitudes are calibrated against the PS1 catalog and the J-band is calibrated with the 2MASS Catalog. All magnitudes are provided in the AB system and are not corrected for Galactic extinction.
We thank Christoph Ries from the staff of the Wendelstein Observatory for obtaining these observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/39346.
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