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.
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"- FACT follow-up of IceCube20160731
- GRB 160726A: CALET Gamma-Ray Burst Monitor detection
- GRB 160801A: Swift-XRT refined Analysis
- GRB 160801A: Swift-BAT refined analysis
- Global MASTER net follow up of IceCube-160731A
- Swift follow up of IceCube-160731A
- GRB 160801A: Enhanced Swift-XRT position
- GRB 160801A: MITSuME Okayama upper limits
- GRB 160801A: Swift detection of a burst
- HAWC follow up of IceCube 160731
- GRB 160716A: TAROT La Silla observatory optical observations
- GRB160720A: Astrosat CZTI detection
- GRB160709A: Astrosat CZTI detection of short GRB
- GRB160703A: Astrosat CZTI detection
- GRB 160705B: 15 GHz upper limits from AMI
- GRB 160703A: 15 GHz upper limits from AMI
- GBM observation of SGR-like burst from the direction of PSR 1119-6127
- Trigger 706396: Swift detection of a short burst from PSR 1119-6127
- GRB 160726A, Swift-BAT refined analysis
- Konus-Wind observation of short GRB 160726A
- GRB 160726A: Fermi GBM observation
- GRB 160726A: Swift detection of a short burst
- GRB 160721A: CALET Gamma-Ray Burst Monitor detection
- GRB 160720A CALET Gamma-Ray Burst Monitor detection
- GRB 160720A: Lomonosov BDRG gamma ray detection and MASTER limit
- Konus-Wind observation of GRB 160720A
- IPN Triangulation of GRB 160720A
- GRB 160703, GRB 160705, GRB 160720, SGR1935+2154: First SGRs and GRBs detected by Lomonosov.
- GRB 160720A: Fermi GBM detection
- Fermi GBM trigger 490701713/160720418 is not a GRB
- Fermi GBM trigger 490365157/160716523 is not a GRB
- GRB 160716A: Swift/UVOT Detection
- GRB 160714A: Swift/UVOT Upper Limits
- GRB 160716A: Swift-BAT refined analysis
- GRB 160716A: Swift-XRT refined Analysis
- GRB 160716A: Enhanced Swift-XRT position
- GRB 160716A: Swift detection of a burst
- Swift Trigger 704327: KAIT Optical Observations
- Swift Trigger 704444 is probably not an astrophysical event.
- GRB 160712A: Swift-BAT refined analysis
- GRB 160714A: TAROT Calern observatory optical observations
- GRB 160714A: Swift-XRT observations
- GRB 160623A: afterglow spectroscopy by GTC and independent redshift determination
- GRB 160714A: Fermi GBM observation
- GRB 160623A: optical astrometry, photometry, and redshift
- Swift-BAT trigger 704327 was due to noise
- Fermi GBM trigger 490193747/160714539 is not a GRB
- GRB 160714A: Swift-BAT refined analysis,
- Swift Trigger 704327: MASTER syncronous optical observations
- GRB 160714A: MASTER early optical observations
- GRB 160712A: Further GROND observations
- GRB 160709A CALET Gamma-Ray Burst Monitor detection
- Swift Trigger 704327: a possible GRB
- GRB 160714A: Optical observations from OSN
- GRB 160714A: Swift-XRT observations
- GRB 160714A: Swift detection of a short burst
- GRB 160712A: Swift/UVOT Upper Limits
- GRB 160712A: RATIR Optical and NIR Observations
- Konus-Wind observation of GRB 160712A
- GRB 160712A: GROND observations
- GRB 160712A: Swift-XRT refined Analysis
- GRB 160712A: Skynet R-COP observations
- GRB 160712A: Enhanced Swift-XRT position
- GRB 160629A: 15 GHz detections and upper limits from AMI
- GRB 160624A: 15 GHz upper limits from AMI
- GRB 160712A: Initial Swift/UVOT observations
- GRB 160712A: Swift-XRT observations
- GRB 160712A: Global MASTER-Net optical observation
- GRB 160712A: Swift detection of a burst
- GRB 160625B: Global MASTER-Crimea prompt optical emission detection (fwd)
- GRB 160709A: MASTER early imaging Swift BAT error box
- GRB 160709A, Swift-BAT detection and localization
- GRB 160625B: TSHAO optical observations
- GRB 160709A: Swift-XRT observations
- GRB 160709A: Global MASTER Net Fermi GBM Alerts observations
- Konus-Wind observation of GRB 160709A (short/hard)
- GRB 160709A: Fermi GBM Observations
- GRB 160709A: Fermi-LAT detection
- GRB 160709A: Tiled Swift observations
- Fermi GBM trigger 489771293/160709649 is not a GRB
- GRB 160705B: TAROT Calern observatory optical observations
- GRB 160628A CALET Gamma-Ray Burst Monitor detection
- GRB 160629A: Mondy optical observations
- GRB 160629A: AbAO optical observations
- GRB 160703A: Keck-I/LRIS Optical Observations
- Konus-Wind observation of GRB 160702A (short/hard)
- IPN Triangulation of GRB 160702A (short/hard)
- SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
- GRB 160705B: Swift/UVOT Upper Limits
- GRB 160705B: RATIR Optical and NIR Observations and Confirmation of the Fading Afterglow
- GRB 160705B: Swift-BAT refined analysis
- GRB 160623A: Astrosat CZTI detection
- GRB 160705B: Swift-XRT refined Analysis
- GRB 160705B: Enhanced Swift-XRT position
- GRB 160705B: LT optical candidate
- GRB 160705B: Swift detection of a burst
- GRB 160703A: Swift/UVOT Detection
- GRB 160703A: Swift-XRT afterglow detection
- GRB 160705A/MAXI J0748-149: MAXI/GSC detection
- GRB 160703A: MITSuME Ishigakijima Optical Observation