February 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37376] IPN triangulation of GRB 250217C (short)
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39365 SUBJECT: IPN triangulation of GRB 250217C (short) DATE: 25/02/18 16:19:04 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, G. Waratkar, J.Joshi, V. Bhalerao, D. Bhattacharya, and S. Vadawale, on behalf of the Astrosat-CZTI team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report: The bright, short-duration GRB 250217C (Fermi-GBM detection: The Fermi GBM team, GCN 39357; AstroSat-CZTI detection: Tembhurnikar et al., GCN 39359) was detected by Fermi (GBM trigger 761529286), AstroSat (CZTI), Konus-Wind, INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND) at about 86082 s UT (23:54:42). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 122.164 (08h 08m 39s) +45.257 (+45d 15' 24") Corners: 121.397 (08h 05m 35s) +45.429 (+45d 25' 44") 122.008 (08h 08m 02s) +45.505 (+45d 30' 17") 122.915 (08h 11m 40s) +45.069 (+45d 04' 08") 122.314 (08h 09m 15s) +45.007 (+45d 00' 27") --------------------------------------------- The error box area is 818 sq. arcmin, and its maximum dimension is 1.13 deg (the minimum one is 17.6 arcmin). The Sun distance was 137 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM (GCN 39357) localization. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250217_T86086/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. Swift-XRT ToO has been submitted. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/39365. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37375] Transient SVOM/sb25021804: COLIBRÍ/DDRAGO Optical Upper Limits on the Optical Counterpart
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39364 SUBJECT: Transient SVOM/sb25021804: COLIBRÍ/DDRAGO Optical Upper Limits on the Optical Counterpart DATE: 25/02/18 16:18:24 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Antonio de Ugarte Postigo (LAM), Alan M. Watson (UNAM), Jean-Luc Atteia (IRAP), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Dalya Akl (AUS), Camila Angulo (UNAM), Sarah Antier (OCA), Rosa L. Becerra (U Roma), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Noémie Globus (UNAM), Kin Ocelotl López (UNAM), Francesco Magnani (CPPM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), and Benjamin Schneider (LAM) report: We imaged the field of SVOM trigger sb25021804 (Wang et al., GCN 39363) with the DDRAGO wide-field imager on the COLIBRÍ telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico. The coordinates of this trigger are about 6 arcmin north of the galaxy NGC 4889, the brightest galaxy in the Coma Cluster (Abell 1656). The uncertainty radius is 10.4 arcmin, and so includes much of the central region of the cluster. We observed from 2025-02-18 09:44 UTC to 11:51 UTC (2.71 to 4.52 hours after the trigger) and obtained 53 minutes of exposure in the i filter through patchy clouds and with high winds. The data were coadded with custom software and analyzed in STDWeb/STDPipe (Karpov 2021), with photometric calibration against Pan-STARRS DR1 and image subtraction against Pan-STARRS DR2. Our photometry is not corrected for Galactic extinction. Our image reaches an AB 5-sigma limiting magnitude of i > 21.7 We have performed image subtraction and see no obvious counterpart. The detection of a counterpart with Swift/XRT or SVOM/MXT would facilitate searches for a faint counterpart. We warmly thank the COLIBRÍ and DDRAGO engineering teams and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/39364. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37374] SVOM/sb25021804: SVOM detection of a long X-ray transient
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39363 SUBJECT: SVOM/sb25021804: SVOM detection of a long X-ray transient DATE: 25/02/18 15:56:15 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU <s.schanne(a)cea.fr> C.-W. Wang, W.-J. Tan (IHEP), D. Turpin, S. Schanne, N. Dagoneau (CEA) report on behalf of the SVOM mission team: The SVOM/ECLAIRs telescope triggered and located a long duration soft X-ray transient (SVOM burst-id sb25021804) starting at 2025-02-18T07:20:27 UTC (Tb). The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by the Image Trigger (IMT) and only 1 alert was produced with a signal-to-noise ratio of 7.56 in the 5-8 keV energy band over a time window of 22 minutes starting at Tb. The sub-image transmitted shows a clean point-like source. The localization of the alert is R.A., Dec = 195.020, 28.078 degrees: RA (J2000) = 13h00m04.93s Dec (J2000) = 28d04m39.02s with a 90% C.L. radius of 10.4 arcmin (including systematic error of 2 arcmin added in quadrature). We notice that this error-box contains several X-ray sources which could produce such a transient, including 4 AGNs and the ULX-candidate labelled "[SRW2012] Src. 6" in Simbad, located at 9.2 arcmin distance. This trigger did not reach the slew threshold, hence no automatic slew was performed. A SVOM ToO has been scheduled and a Swift XRT ToO has been requested. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. The Burst Advocate (BA) on shift for this burst is Chen-Wei Wang (IHEP) : cwwang(a)ihep.ac.cn Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst. View this GCN Circular online at https://gcn.nasa.gov/circulars/39363. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37373] GRB 250213A: Swift-XRT observations
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39362 SUBJECT: GRB 250213A: Swift-XRT observations DATE: 25/02/18 15:33:01 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected burst GRB 250213A, collecting 3.3 ks of Photon Counting (PC) mode data between T0+26.1 ks and T0+50.5 ks. Three uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below: Source 2: RA (J2000.0): 112.5572 = 07:30:13.74 Dec (J2000.0): -19.9494 = -19:56:57.9 Error: 9.1 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: (5.8 [+2.0, -1.6])e-3 ct s^-1 Distance: 578 arcsec from SVOM/ECLAIRs position. Flux: (4.2 [+1.4, -1.2])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 3: RA (J2000.0): 112.5390 = 07:30:9.37 Dec (J2000.0): -20.1093 = -20:06:33.6 Error: 6.4 arcsec (radius, 90% conf.) Count-rate: (3.4 [+1.4, -1.2])e-3 ct s^-1 Distance: 175 arcsec from SVOM/ECLAIRs position. Flux: (6.4 [+2.7, -2.2])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 4: RA (J2000.0): 112.2781 = 07:29:6.75 Dec (J2000.0): -20.0889 = -20:05:19.9 Error: 6.3 arcsec (radius, 90% conf.) Count-rate: (3.0 [+1.6, -1.2])e-3 ct s^-1 Distance: 712 arcsec from SVOM/ECLAIRs position. Flux: (5.9 [+3.1, -2.3])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) A catalogued source was also detected. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021777. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/39362. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37372] LIGO/Virgo/KAGRA S250206dm: AZT-33IK Target Optical Observations
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39361 SUBJECT: LIGO/Virgo/KAGRA S250206dm: AZT-33IK Target Optical Observations DATE: 25/02/18 11:24:47 GMT FROM: Nicolai Pankov at HSE, IKI RAS <colinsergesen(a)gmail.com> N. Pankov (HSE, IKI), A. Pozanenko (IKI, HSE), A. Volnova (IKI), E. Klunko (ISTP) report on behalf of the IKI GRB-FuN collaboration: We observed the fields of 8 GLADE+ galaxies contained in the 50% probability volume traced by the LIGO/Virgo/KAGRA in the latest Bilby.offline1.multiorder.fits skymap file for S250206dm (LIGO Scientific Collaboration, GCN 39175; LIGO Scientific Collaboration, GCN 39184). The observations were carried out with the 1.5-meter telescope of the Sayan Solar Observatory located at Mondy, Buryatia. The series of the 3*120 sec exposures in the R-filter were taken on epochs of Feb. 12 and Feb. 14. We performed subtraction of the Feb.14 stacked images from the ones taken on Feb.12. Our preliminary analysis of the residual difference images does not reveal any prominent optical transient located in the vicinity of the observed GLADE+ galaxies. The preliminary 3-sigma upper limits on the subtracted images are as follows: Galaxy UTstart MJDmid Exp. Filter UL FWHM ------ ------- ------ ---- ------ ---- ---- J021712_47_+532137_62 2025-02-12T14:32:26 60718.60795 3*120 R 19.7 2.9 J021738_38_+521958_56 2025-02-12T14:05:11 60718.58902 3*120 R 20.6 3.1 J021815_59_+530110_02 2025-02-12T14:25:32 60718.60315 3*120 R 20.3 2.9 J021826_85_+523810_42 2025-02-12T14:11:41 60718.59354 3*120 R 19.8 3.4 J021830_02_+524021_45 2025-02-12T14:18:37 60718.59835 3*120 R 19.8 3.0 J022347_90_+514635_27 2025-02-12T13:58:32 60718.58440 3*120 R 20.2 2.8 J022352_96_+513006_26 2025-02-12T13:44:43 60718.57481 3*120 R 20.3 2.8 J022405_82_+513240_21 2025-02-12T13:51:37 60718.57960 3*120 R 20.4 3.0 * 60712.89271 MJD -- The LIGO trigger time for S250206dm The photometry is based on nearby stars from the USNO-B1.0 catalog (R2 magnitudes) and has not been corrected for the Galactic extinction. The further analysis is ongoing. View this GCN Circular online at https://gcn.nasa.gov/circulars/39361. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37371] GRB 250216A: AstroSat CZTI detection
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39360 SUBJECT: GRB 250216A: AstroSat CZTI detection DATE: 25/02/18 05:55:34 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> M. Tembhurnikar (IUCAA), G. Waratkar (IITB), J. Joshi (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed a faint detection of GRB 250216A which was also detected by Fermi/GBM (Fermi-GBM Team, GCN Circ. 39347). Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst. Due to the likely hard nature of the burst, we don’t see any detection in the CZT detectors (20-200 keV). The source was faintly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range and we see only the initial short spike from the Fermi/GBM lightcurve. The light curve peaks at 2025-02-16 20:20:42.4 UTC. The measured peak count rate associated with the burst is 273 (+63, -65) counts/s above the background in the combined data of all quadrants, with a total of 399 (+207, -194) counts. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/39360. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37370] GRB 250217C: AstroSat CZTI detection of a short burst
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39359 SUBJECT: GRB 250217C: AstroSat CZTI detection of a short burst DATE: 25/02/18 05:25:45 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> M. Tembhurnikar (IUCAA), G. Waratkar (IITB), J. Joshi (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a short-duration GRB 250217C which was also detected by Fermi (Fermi-GBM Team, GCN Circ. 39357). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2025-02-17 23:54:41.85 UTC. The measured peak count rate associated with the burst is 1090 (+213, -122) counts/s above the background in the combined data of three quadrants (out of four), with a total of 296 (+53, -56) counts. The local mean background count rate was 273 (+15, -18) counts/s. Using cumulative rates, we measure a T90 of 0.35 (+0.39, -0.09) s. The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2025-02-17 23:54:41.14 UTC. The measured peak count rate associated with the burst is 358 (+63, -67) counts/s above the background in the combined data of all quadrants, with a total of 309 (+169, -171) counts. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb View this GCN Circular online at https://gcn.nasa.gov/circulars/39359. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37369] Fermi GRB 250217C: Global MASTER-Net observations report
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39358 SUBJECT: Fermi GRB 250217C: Global MASTER-Net observations report DATE: 25/02/18 00:16:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250217C ( Fermi GBM team, GCN 39357) errorbox 588 sec after notice time and 626 sec after trigger time at 2025-02-18 00:05:08 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 74 deg. The sun altitude is -42.9 deg. The galactic latitude b = 38 deg., longitude l = 191 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2781342 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 657 | 2025-02-18 00:05:08 | MASTER-SAAO | (08h 45m 43.52s , +32d 50m 06.0s) | C | 60 | 17.9 | 717 | 2025-02-18 00:05:08 | MASTER-SAAO | (08h 45m 43.52s , +32d 50m 05.9s) | C | 180 | 18.5 | Coadd 736 | 2025-02-18 00:06:27 | MASTER-SAAO | (08h 45m 43.62s , +32d 50m 10.7s) | C | 60 | 17.6 | 815 | 2025-02-18 00:07:46 | MASTER-SAAO | (08h 45m 43.81s , +32d 50m 10.7s) | C | 60 | 17.5 | 894 | 2025-02-18 00:09:05 | MASTER-SAAO | (08h 45m 44.00s , +32d 50m 14.7s) | C | 60 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39358. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37368] GRB 250217C: Fermi GBM Final Real-time Localization
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39357 SUBJECT: GRB 250217C: Fermi GBM Final Real-time Localization DATE: 25/02/18 00:05:15 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely SHORT GRB At 23:54:41 UT on 17 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250217C (trigger 761529286.801804 / 250217996). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 131.6, Dec = 32.9 (J2000 degrees, equivalent to J2000 08h 46m, 32d 53'), with a statistical uncertainty of 5.5 degrees. The angle from the Fermi LAT boresight is 100.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250217996/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250217996/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250217996/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39357. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37367] IceCube-Cascade 250215A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 17 Feb '25

17 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39356 SUBJECT: IceCube-Cascade 250215A: Upper limits from a search for additional neutrino events in IceCube DATE: 25/02/17 22:56:25 GMT FROM: Sam Hori at IceCube/U Wisc-Madison <sahori(a)wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-Cascade 250215A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/140500_12724443.amon) in a time range of 1000 seconds centered on the alert event time (2025-02-15 10:57:22.720 UTC to 2025-02-15 11:14:02.720 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-Cascade 250215A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-Cascade 250215A ranges from 1.4e-01 to 1.9e+00 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 1e+06 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2025-02-14 11:05:42.720 UTC to 2025-02-16 11:05:42.720 UTC). In this case, we report a p-value of 0.56, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-Cascade 250215A ranges from 1.6e-01 to 1.9e+00 GeV cm^-2 in a 2 day time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) View this GCN Circular online at https://gcn.nasa.gov/circulars/39356. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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