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.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"28235 results found.
- EP240506a: TRT optical upper limit
- LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S240422ed: Upper limits from a two-week IceCube neutrino search
- EP240506a: Optical upper limit with Kinder observations
- IPN triangulation of GRB 240504A
- GRB 240502A: 1.3m DFOT Optical upper limit
- EP240506a: EP-WXT detection of a new fast X-ray transient
- LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
- GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S240505av: Identification of a GW compact binary merger candidate
- Fermi trigger No 736461232: Global MASTER-Net observations report
- GW170817: VLA observations at ~5.5 yrs since merger
- GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
- GRB 240502A: Fermi GBM Observation
- GRB 240415A 1.3m DFOT Optical upper limit
- LIGO/Virgo/KAGRA S240501an: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
- GRB 240426A: VZLUSAT-2 detection
- GRB 240425A: VZLUSAT-2 detection
- MeerKAT Discovery of a Probable Radio Counterpart to EP240414a
- GRB 240501B: AstroSat CZTI detection
- GRB 240501A: Fermi GBM Final Real-time Localization
- GRB 240408B: VZLUSAT-2 detection
- GRB 240407A: VZLUSAT-2 detection
- LIGO/Virgo/KAGRA S240501an: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240430ca: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S240430ca: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240422ed: GECKO/7DT ToO observations
- Additional DECam GW-MMADS Candidates from three nights of observations
- Fermi-LAT gamma-ray observations of IceCube-240424A
- LIGO/Virgo/KAGRA S240426s: Updated Sky localization
- LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
- LIGO/Virgo/KAGRA S240426dl: Updated Sky localization
- LIGO/Virgo/KAGRA S240428dr: Updated Sky localization
- LIGO/Virgo/KAGRA S240422ed: GECKO/KMTNet ToO observations
- LIGO/Virgo/KAGRA S240428dr: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240422ed: J-band non-detection of J-GEM24a
- LIGO/Virgo/KAGRA S240422ed: DDOTI Optical Upper Limit for J-GEM24a
- EP240426b: AST3-2 optical upper limit
- LIGO/Virgo/KAGRA S240422ed: Observations with 1.6m Mephisto
- LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
- LIGO/Virgo/KAGRA S240422ed: NOT optical observations of EP240426a
- EP240426b: EP-WXT detection of a new fast X-ray transient
- LIGO/Virgo/KAGRA S240422ed: Archival radio detection of EP240426a
- LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfq, AT2024hfr, AT2024hfs, and AT2024hfx
- LIGO/Virgo/KAGRA S240422ed: BOOTES-6/DPRT optical upper limits for EP240426a
- LIGO/VIRGO/KAGRA S240422ed: Historical variability for EP240426a
- GRB 240426A: AstroSat CZTI detection
- XMM-Newton observation of EP240426a
- LIGO/Virgo/KAGRA S240426dl: Identification of a GW compact binary merger candidate
- GRB 240414A: NOEMA detection
- LIGO/Virgo/KAGRA S240422ed: EP240426a possible optical detection
- EP240426a: GMG optical upper limit
- LVK S240422ed: Further Swift-XRT followup of three sources
- LIGO/Virgo/KAGRA S240426s: Identification of a GW compact binary merger candidate
- IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S240422ed: PRIME near-infrared observations
- LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
- LIGO/Virgo/KAGRA S240422ed: Second night Pan-STARRS observations of the skymap
- LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
- LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
- LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA and Kilonova-Catcher galaxy targeting observations
- LIGO/Virgo/KAGRA S240422ed: Additional DECam GW-MMADS Candidates from the first two nights of observations
- LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
- GRB 240419B: Swift-BAT refined analysis
- GRB 240421B: Swift-BAT refined analysis
- GRB 240422A: Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S240422ed: Archival BlackGEM/MeerLICHT detections of AT 2024hdr & AT 2024hdq
- LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
- LIGO/Virgo/KAGRA S240422ed: No significant counterpart candidates in HAWC observations
- LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA/FRAM Observations
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
- LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
- LIGO/Virgo/KAGRA S240422ed: Early X-ray Upper Limits from EP-WXT for the LVK Sky Localization Region
- LIGO/Virgo/KAGRA S240422ed: J-band non-detection of Mag24a
- LIGO/Virgo/KAGRA S240422ed: Continued Imaging of Mag24a
- LIGO/Virgo/KAGRA S240422ed: Archival DECaPSs2 observations of the field of Mag24a
- LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
- LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
- LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
- IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S240421ar: Updated Sky localization
- LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
- LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from Pan-STARRS observations of the skymap
- LIGO/Virgo/KAGRA S240422ed: No Counterparts in DDOTI/OAN Optical Observations
- GRB 240419A: Swift-BAT refined analysis
- GRB 240418A: Swift-BAT refined analysis
- LXT240402A/GRB240402B: Chandra X-ray detection
- LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
- LIGO/Virgo/KAGRA S240422ed: WINTER near-infrared J-band observations
- LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam observations
- LIGO/Virgo/KAGRA S240422ed: Updated NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
- LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S240422ed: Updated Sky localization and EM Bright Classification