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@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 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. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...