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').
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"
2722 results found.
- Fermi trigger No 737168073: Global MASTER-Net observations report
- Fermi trigger No 737105243: Global MASTER-Net observations report
- GRB 240511A: Fermi GBM Final Real-time Localization
- Fermi trigger No 737111207: Global MASTER-Net observations report
- IPN triangulation of GRB 240504A
- Fermi trigger No 736564880: Global MASTER-Net observations report
- GRB 240503A: AstroSat CZTI detection
- Fermi trigger No 736387941: Global MASTER-Net observations report
- Fermi GRB 240501A: Global MASTER-Net observations report
- Fermi trigger No 736197684: Global MASTER-Net observations report
- GRB 240501B: AstroSat CZTI detection
- GRB 240426A: AstroSat CZTI detection
- EP240426a: YAHPT optical upper limit
- LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
- LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
- LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration
- LIGO/Virgo/KAGRA S240422ed: No significant candidates in GRANDMA and Kilonova-Catcher galaxy targeting observations
- LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
- LIGO/Virgo/KAGRA S240422ed: Subaru/MOIRCS near-infrared observations by J-GEM Collaboration
- LIGO/Virgo/KAGRA S240422ed: GOTO counterpart search
- LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility observations and candidates
- LIGO/Virgo/KAGRA S240422ed: Magellan Observations
- Fermi GRB 240422A: Global MASTER-Net observations report
- Fermi GRB 240421B: Global MASTER-Net observations report
- Fermi trigger No 735280430: Global MASTER-Net observations report
- GRB 240418A: TSHAO Zeiss-1000 optical upper limit
- Fermi GRB 240417A: Global MASTER-Net observations report
- Improved IPN triangulation of GRB 240411A
- EP240416A: MASTER optical observations
- Fermi GRB 240415A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
- GRB 240411B: CrAO/ZTSh optical observations
- IceCube Alert 240412.23: Global MASTER-Net observations report
- Swift Trigger 1220736: detection of 4U 1543-62.
- Fermi GRB 240407A: Global MASTER-Net observations report
- GRB 240405B: Fermi GBM Final Real-time Localization
- GRB 240405A: Fermi GBM Final Real-time Localization
- LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
- Konus-Wind detection of LXT 240402A/GRB 240402B
- LXT 240402A: MASTER optical observations with AGN in error-box
- GRB 240402B: GECAM-C detection
- X-ray transient LXT 240402A: LEIA detection
- EP240331A: MASTER optical observations
- Fermi trigger No 733366352: Global MASTER-Net observations report
- Fermi GRB 240329A: Global MASTER-Net observations report
- GRB 240329A: Fermi GBM Final Real-time Localization
- Fermi GRB 240328B: Global MASTER-Net observations report
- Fermi GRB 240328A: Global MASTER-Net observations report
- IceCube-240327B: No candidates from the Zwicky Transient Facility
- GRB 240328A: Fermi GBM Final Real-time Localization
- IceCube Alert 240327.68: Global MASTER-Net observations report
- Fermi trigger No 733097506: Global MASTER-Net observations report
- Fermi trigger No 733092476: Global MASTER-Net observations report
- Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
- GRB 240320A: Fermi GBM Final Real-time Localization
- Fermi GRB 240318A: Global MASTER-Net observations report
- GRB 240317A: AstroSat CZTI detection
- Fermi GRB 240317B: Global MASTER-Net observations report
- Fermi trigger No 732299243: Global MASTER-Net observations report
- Fermi trigger No 731839490: Global MASTER-Net observations report
- Fermi GRB 240310A: Global MASTER-Net observations report
- Fermi GRB 240306A: Global MASTER-Net observations report
- Fermi GRB 240305A: Global MASTER-Net observations report
- GRB 240218A: ALMA detection
- IPN triangulation of GRB 240229A
- GRB240218A: ATCA observation of the radio counterpart
- Swift Trigger 1218645: Another detection of Swift J151857.0-572147
- Konus-Wind detection of GRB 240225B (long)
- Fermi GRB 240227A: Global MASTER-Net observations report
- GRB 240218A: CMO SAI NIR upper limit
- Fermi trigger No 730618809: Global MASTER-Net observations report
- GRB 240218A: VLA detection
- Transient EPW20240219aa: 7DT Optical Upper Limits
- GRB 240215B: GRBAlpha detection
- Fermi trigger No 729914426: Global MASTER-Net observations report
- GRB 240218A: REM detection of a NIR afterglow candidate
- Swift GRB240218.08: Global MASTER-Net observations report
- Fermi trigger No 729703985: Global MASTER-Net observations report
- GRB 240214A/1H 0451-560: MAXI/GSC detection
- Fermi GRB 240213A: Global MASTER-Net observations report
- GRB 240209A: GOTO optical counterpart candidate
- Fermi trigger No 729152364: Global MASTER-Net observations report
- Fermi trigger No 729012023: Global MASTER-Net observations report
- GRB 240205B: Fermi GBM Observation
- Fermi trigger No 728749569: Global MASTER-Net observations report
- GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
- Swift GRB240205.93: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 728740048/240204491 is not a GRB
- Fermi trigger No 728796365: Global MASTER-Net observations report
- IceCube Alert 240204.38: Global MASTER-Net observations report
- GRB 240127A: Fermi GBM Final Real-time Localization
- GRB 240123A: GRBAlpha detection
- GRB 240118A: Mondy optical observations
- GRB 240118A: Swift-XRT afterglow detection
- GRB 240118A: AbAO optical upper limit
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A
- IPN triangulation of GRB 240112A (long)
- GRB 240115B: AstroSat CZTI detection
- GRB 240107A: VZLUSAT-2 detection