GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.
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To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"- Fermi GRB 250212A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S250206dm: NEWFIRM NIR Follow-up of AT2025ber
- GRB 250205A: Calapai Observatory, Massa S. Giorgio (Messina), upper limit
- Fermi trigger No 760945500: Global MASTER-Net observations report
- EP250207b: NOT optical counterpart candidate
- GRB 250211A: SVOM trigger sb25021103 is not a GRB
- GRB 250211B: A long GRB detected by INTEGRAL
- LIGO/Virgo/KAGRA S250206dm: GECKO Continued Observaiton with 7DT
- GRB 250211A: Swift ToO observations
- Integral GRB250211.89: Global MASTER-Net observations report
- GRB 250212A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S250206dm: AT 2025bbo observations with WFST
- LIGO/Virgo/KAGRA S250211be: Updated Sky localization
- GRB 250207A: Fermi GBM Observation
- GRB 250206A: Fermi GBM Observation
- GRB 250205A / EP250205A: radio detection with the VLA
- IceCube-250207A: One candidate from the Zwicky Transient Facility
- EP250207b: Tentative z-band brightening source
- LIGO/Virgo/KAGRA S250206dm: continued in SOAR galaxy targeted observations and identification of one possible transient
- LIGO/Virgo/KAGRA S250206dm: Kinder confirmation of a possible artefact in AT 2025bbo
- Konus-Wind detection of GRB 250207A
- Konus-Wind detection of GRB 250206A
- GRB 250210A: SVOM/GRM observation of a long burst
- EP250207b: Liverpool Telescope possible optical counterpart
- EP250207b: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 760945500/250211240 is not a GRB
- Gemini-South spectroscopic redshift of EP250207b host galaxy candidate (z=0.082)
- LIGO/Virgo/KAGRA S250211be: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S250211aa: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S250211aa: Identification of a GW compact binary merger candidate
- GRB 250207A: Skynet optical afterglow observations
- LIGO/VIRGO/KAGRA S250206dm: AT 2025bbo spectroscopic observations with NIRES on Keck II
- LIGO/Virgo/KAGRA S250206dm: Gemini-North spectroscopic observation of AT2025bbo and its host galaxy
- GRB 241128A: VIRT Optical Upper Limit
- EP250207b: Gemini GMOS-N z-band observations
- EP250207A: Upper limits from Fermi-GBM Observations
- GRB 250210A: INTEGRAL SPI-ACS detection
- GRB 250210A: AstroSat CZTI detection
- EP250207b: a new X-ray transient detected by Einstein Probe
- LIGO/Virgo/KAGRA S250206dm: MASTER detection AT2025bbo
- GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
- Fermi GRB 250210A: Global MASTER-Net observations report
- GRB 250210A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S250206dm: Upper limits from GECAM Observations
- IceCube-250207A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S250206dm: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of AT2025bbo and Galaxies in the Localization Volume
- IceCube Alert 250207.09: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S250206dm: Observations from WINTER
- GRB 250204B: GRBAlpha detection
- GRB 250204A: GRBAlpha detection
- LIGO/Virgo/KAGRA S250206dm & FRB 20250206A: MASTER observations and possible mother galaxy
- LIGO/Virgo/KAGRA S250206dm: Optical observations of candidate AT 2025bbo with Kinder
- Fermi-LAT Gamma-ray Observations of IceCube-250207A
- GRB 250207A: 1.3m DFOT Optical observations
- LIGO/Virgo/KAGRA S250206dm: WFST follow-up observations
- GRB 250206A: Swift-XRT observations
- LIGO/Virgo/KAGRA S250206dm: FRB 20250206A BOOTES-5 and 2.2m CAHA optical upper limits
- GRB 250129A: GRANDMA Continued Afterglow Detection
- GRB 250207A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S250206dm: further Pan-STARRS observations and one candidate AT2025bbo
- LIGO/Virgo/KAGRA S250207bg: Updated NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S250207bg: Updated Sky localization
- LIGO/Virgo/KAGRA S250206dm: GECKO Observation with 7DT and KMTNet
- GRB 250205A: 1.3m DFOT optical upper limit
- GRB 250206A: Tiled Swift observations
- LIGO/Virgo/KAGRA S250118az: Updated Sky localization
- LIGO/Virgo/KAGRA S250208ad: Updated Sky localization
- GRB 250206A: EIRSAT-1 GMOD Detection
- LIGO/Virgo/KAGRA S250206dm: (Update-7) NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S250206dm: NEWFIRM NIR Observations
- GRB 250206A: Fermi-LAT detection
- GRB 250207B: Swift-XRT observations
- LIGO/Virgo/KAGRA S250206dm: Updated Sky localization and EM Bright Classification
- IceCube-250203A: No transient candidates from the Zwicky Transient Facility
- LIGO/Virgo/KAGRA S250206dm: Spectroscopic Classification of AT2025bay and AT2025baz with Keck I/LRIS
- LIGO/Virgo/KAGRA S250206dm: Candidates from the Zwicky Transient Facility
- LIGO/Virgo/KAGRA S250206dm: ePESSTO+ classification of AT2025bar
- LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of the DDOTI optical candidates
- GRB 250208A: Fermi GBM Final Real-time Localization
- EP250207a: EP-WXT detection and XRT follow-up observation
- LIGO/Virgo/KAGRA S250208ad: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S250206dm: MMT galaxy targeted observations
- GRB 250207A: Swift-XRT refined Analysis
- LIGO/Virgo/KAGRA S250206dm: FRB 20250206A & "Time Machine" Effect.
- EP-WXT trigger 01709131361: correction to GCN 39214
- EP trigger 01709131361 (possible EP250207a): NOT optical observations and flaring star
- GRB 250207A: Enhanced Swift-XRT position
- CHIME/FRB source FRB 20250206A detected less than 1 minute after LIGO-Virgo-Kagra (LVK) S250206dm, however the probability of spatial coincidence is order 0.1%
- LIGO/Virgo/KAGRA S250206dm: GOTO counterpart search update - AT2025bar
- EP-WXT trigger 01709131361 / LIGO/Virgo/KAGRA S250206dm: FTW optical and NIR observations
- GRB 250129A: ABObservatory SLOAN r’ afterglow detection
- GRB 250207A: REM IR afterglow detection
- LIGO/Virgo/KAGRA S250206dm: ATLAS observations of the skymap
- LIGO/Virgo/KAGRA S250206dm: Pan-STARRS survey of the skymap for optical transients
- GRB 250207A: FRAM-Auger optical detection
- LIGO/Virgo/KAGRA S250206dm: DDOTI Upper Limits
- GRB 250207B: Tiled Swift observations
- LIGO/Virgo/KAGRA S250207bg: NED Galaxies in the Localization Volume
- Konus-Wind detection of GRB 250204B