GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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').
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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.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"8474 results found.
- LIGO/Virgo/KAGRA S240422ed: DECam GW-MMADS Candidates
- LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
- LIGO/Virgo/KAGRA S240422ed: Magellan Detection of a Potential Electromagnetic Counterpart
- LIGO/Virgo/KAGRA S240422ed: SAGUARO upper limits from CSS
- IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S240421ar: Updated Sky localization
- LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from Pan-STARRS observations of the skymap
- LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search
- LIGO/Virgo/KAGRA S240423br: Retraction of GW compact binary merger candidate
- LIGO/Virgo/KAGRA S240422ed: no candidate counterparts from ATLAS observations
- LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam observations
- LIGO/Virgo/KAGRA S240422ed: Magellan 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
- LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S240422ed: Identification of a GW compact binary merger candidate
- LIGO/Virgo/Kagra S240422ed: NED Galaxies in the Localization Volume
- GRB 240414A: radio detection with the VLA
- GRB 240414A: AMI-LA radio observations
- EP240420a: Xinglong decaying optical counterpart
- GRB 240421B: Swift detection of a burst
- EP240420a: Nanshan optical counterpart observations
- EP240420a: GWAC-F50A optical upper limit
- LIGO/Virgo/KAGRA S240421ar: Identification of a GW unmodeled transient candidate
- EP240420a: NOT optical counterpart candidate and potential host
- GRB240418A - Candidate afterglow from NIRES
- IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
- IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 240419B: optical afterglow from the NOT
- LIGO/Virgo/KAGRA S240420aw: Retraction of GW compact binary merger candidate
- GRB 240419B: Swift detection of a burst
- GRB 240419A: Swift detection of a burst
- GRB 240418A: AKO Upper Limit
- GRB 240411A: GOTO early optical upper limits
- GRB 240418A: Swift detection of a burst
- LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
- EP240414a: GSP detects optical candidate counterpart AT2024gsa
- LIGO/Virgo/KAGRA S240413p: DECam GW-MMADS candidates
- IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube
- EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa
- LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
- LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
- EP 240416a: Xinglong and NOT decaying optical counterpart
- EP240416a: Kinder optical counterpart candidate
- GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
- GRB 240415A: Earliest optical followup with the Kinder observations
- GRB 240415B: Swift ToO observations
- GRB 240415A: OHP/T193 optical observations
- IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
- X-ray transient EP 240414a - GTC spectroscopic observations
- EP 240414a: NOT optical counterpart confirmation
- GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
- GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- EP240413A: GOTO optical upper limits
- EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
- LIGO/Virgo/KAGRA S240413p: Updated Sky localization
- GRB 240411B: Kinder observations with Lulin observatory
- LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S240413p: Identification of a GW compact binary merger candidate
- IceCube-240412A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 240411B: OHP/T193 optical observations
- GRB 240411B: Swift detection of a burst
- EP240408a: GROND detection of a candidate counterpart
- IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
- GRB/FXT 240402B: Kinder optical counterpart candidate
- IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
- GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
- IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
- IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-240327B: No candidates from the Zwicky Transient Facility
- IceCube-240327B - IceCube observation of a high-energy neutrino candidate track-like event
- IceCube-240327A - IceCube observation of a high-energy neutrino candidate track-like event
- Transient EPW20240219aa: REM optical/NIR further observations
- X-ray transient EP240315a: Montarrenti Observatory optical upper limit
- X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
- X-ray transient EP240315a: Nanshan/HMT optical upper limit
- Einstein Probe detected of a fast X-ray transient EP240315a
- IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
- GRB 231215A: further radio observations with the VLA
- IceCube-240307A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
- Swift detection of Swift J151857.0-572147
- GRB 240303A: Swift detection of a burst
- IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-240229A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 240225B: Swift ToO observations
- GRB 240225B : MITSuME Akeno optical afterglow candidate detection
- GRB 240225B: 3.6m DOT observation
- GRB 240225B: NOT optical observations
- Swift-BAT triggers 1217729-1217732 are not astrophysical
- GRB 240225B: Nanshan/HMT optical afterglow detection
- GRB 240225B: GOTO detection of a candidate optical afterglow
- Transient EPW20240219aa: REM optical/NIR upper limits
- GRB 240225B: Tiled Swift observations
- Swift-BAT triggers 1217218-1217222 are not astrophysical
- Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
- Swift-BAT triggers 1216907-1216911 are not astrophysical