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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"32763 results found.
- GRB 240102A: LCOGT Optical Upper Limits
- GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- GRB 240101A: Terskol Zeiss-2000 optical observations
- GRB 240101C: GRBAlpha detection
- GRB 240101B: Swift/UVOT Upper Limits
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 240101B: KAIT Optical Upper Limit
- GRB 240101A: KAIT Optical Upper Limit
- LIGO/Virgo/KAGRA S231231ag: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231231ag: Identification of a GW compact binary merger candidate
- GRB231230A: Fermi GBM Observation
- GRB 231230A: GOTO optical upper limits
- GRB 231230A: Swift/UVOT Upper Limits
- GRB 231230A: NOT optical upper limits
- IPN triangulation of GRB 231224A (short)
- LIGO/Virgo/KAGRA S231226av: Updated Sky localization
- LIGO/Virgo/KAGRA S231226av: Identification of a GW compact binary merger candidate
- GRB 231222B: GRBAlpha detection
- LIGO/Virgo/KAGRA S231224e: Updated Sky localization and Source Classification
- LIGO/Virgo/KAGRA S231224e: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231223j: Updated Sky localization
- GRB 231222B: Swift-XRT afterglow detection
- LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
- GRB 231222B: Fermi GBM Detection
- GRB 231222A: Tiled Swift observations
- IceCube-231211A: GRANDMA observations of PKS2047+098
- GRID detection of GRB 231215A
- GRB 231220A: Swift-XRT follow-up observations
- GRB 231220A: Swift ToO observations
- GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
- GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
- GRID detection of GRB 231205B
- GRID detection of GRB 231205A
- GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
- GRB 231214B: Fermi GBM observation
- GRB 231216A: optical upper limits from the INAF Asiago Observatory
- GRB 231215A: AMI-LA radio detection
- GRB 231216A: Nanshan/HMT optical upper limit
- GRB 231216A: LCOGT Optical Upper Limits
- GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: Swift-XRT refined analysis correction
- GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: AST3-3 YaoAn Optical Upper Limit
- GRB 231216A: REM NIR upper limits
- GRB 231216A: Swift/UVOT Upper Limits
- GRB 231216A: Swift-BAT refined analysis
- GRB 231215A: Swift-BAT refined analysis
- GRB 231214A: Swift-BAT refined analysis
- GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
- GRB 231216A: GIT optical upper limit
- GRB 231216A: NOT optical upper limits
- GRB 231215A: GRBAlpha detection
- Konus-Wind detection of GRB 231215A
- GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
- GRB 231215A: NOT optical observations
- GRB 231214A: Swift/UVOT Upper Limits
- GRB 231215A: Redshift from OSIRIS+ / GTC
- GRB 231205B: VZLUSAT-2 detection
- GRB 231204A: VZLUSAT-2 detection
- GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
- GRB 231215A: Fermi GBM observation
- GRB 231215A: CALET Gamma-Ray Burst Monitor detection
- GRB 231215A : OHP/T193 optical afterglow detection
- GRB 231215A: Swift/UVOT Detection
- GRB 231215A: AKO Optical Upper Limit
- GRB 231215A: AGILE detection
- GRB 231214A: Fermi GBM observation
- Konus-Wind detection of GRB 231210B
- ATCA observations of GRB 231210B
- GRB 231214A: REM optical/NIR upper limits
- GRB 231215A: GROWTH-India optical follow-up
- GRB 231215A : Nanshan/HMT optical observations
- GRB 231215A: AstroSat CZTI detection
- GRB 231215A : MITSuME Akeno optical afterglow candidate detection
- GRB 231215A: Mondy optical bright afterglow detection
- GRB 231214A: AstroSat CZTI detection
- GRB 231215C: MASTER OT detection
- GRB 231214A: Fermi-LAT detection
- GRB 231210B: REM optical/NIR upper limits
- IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S231213ap: Updated Sky localization
- LIGO/Virgo/KAGRA S231213ap: Identification of a GW compact binary merger candidate
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
- GRB 231210B: MeerLICHT afterglow observations
- GRB 231210B: Swift-BAT refined analysis
- IceCube-231202A: No candidates from the Zwicky Transient Facility
- GRB 231210B: VLT/X-shooter redshift
- GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
- IPN triangulation of GRB 231129C
- GRB 231208A: GRBAlpha detection
- GRB231205B: Swift/UVOT Upper Limits
- GRB 231208A: Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S231206ca: Updated Sky localization
- IPN triangulation of GRB 231205A
- GRB 231205B: Swift-BAT refined analysis
- GRB 231205B: 1.3m DFOT Optical upper limit
- LIGO/Virgo/KAGRA S231206cc: Updated Sky localization and Source Classification
- GRB 231206A: joint location of multiple instruments by ETJASMIN
- GRB 231205B: optical upper limit in TSHAOand AbAO
- LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate