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"- GRB 160824A: Enhanced Swift-XRT position
- GRB 160824B: Fermi GBM detection
- GRB 160824A: Swift detection of a burst
- GRB 160821B: VLA 5.0 GHz observations
- Konus-Wind observation of GRB 160822A
- Konus-Wind observation of GRB 160820A
- GRB 160821B: Fermi GBM Detection
- GRB 160821B: Swift-XRT refined Analysis
- GRB 160821A: Swift-BAT refined analysis
- Short GRB 160821B: MASTER early optical observations
- GRB 160821B: NOT optical afterglow candidate
- GRB 160821B: Swift detection of a short burst
- GRB 160821A: TAROT Calern observatory optical detection
- GRB 160821A: Fermi-LAT detection of a bright burst
- GRB 160821A: Swift detection of a bright burst
- INTEGRAL/SPI-ACS observation of IceCube HESE 128340 58537957
- BAT detection and localization of GRB 160819A
- GRB 160816A: Further RATIR Optical and NIR Observations
- GRB 160815A: CALET Gamma-Ray Burst Monitor detection
- GRB 160816A: RATIR Optical and NIR Afterglow Confirmation
- Fermi GBM Observations of IceCube-160806A
- GRB 160816A: Swift/UVOT Detection
- GRB 160816A: IPN annulus
- GRB 160804A: 15 GHz detections and upper limit from AMI
- GRB 160714A: 15 GHz upper limits from AMI
- GRB 160816A: MASTER inspection
- GRB 160816730A: Fermi GBM detection/observation
- GRB 160816A: Swift ToO observations
- GRB 160815A: Swift/UVOT Detection
- Konus-Wind observation of GRB 160814A
- GRB 160815A: Swift-BAT refined analysis
- GRB 160815A: Swift-XRT refined Analysis
- GRB 160815A: Fermi GBM detection/observation
- GRB 160815A: Swift/UVOT Afterglow Detection
- Fermi GBM trigger 160812507/492696620 is not a GRB
- INTEGRAL/SPI-ACS and IBIS_VETO search for prompt gamma-ray counterpart of IceCube-160806A
- Fermi GBM trigger 160810523/492525192 is not a GRB
- GRB 160806A: Fermi GBM observation
- Konus-Wind observation of GRB 160806A
- GRB160802A - Astrosat CZTI detection
- GRB 160802A: CALET Gamma-Ray Burst Monitor detection
- IceCube-160731A: Konus-Wind limits
- GRB 160804A: TSHAO optical observations
- GRB 160804A: GROND observations
- GRB 160804A: VLT/X-shooter redshift
- GRB 160804A: SAO RAS optical observations
- GRB 160804A: TNG optical observations, afterglow fading and candidate host galaxy
- GRB 160804A: Fermi GBM observation
- Konus-Wind observation of GRB 160802A
- GRB 160804A: Swift-BAT refined analysis
- GRB 160804A: Swift/UVOT Detection
- GRB 160804A: Swift-XRT refined Analysis
- GRB 160804A: Swift detection of a burst
- IceCube-160731A: iPTF P48 Observations
- GRB 160801A: Swift/UVOT Upper Limits
- GRB 160801A: SAO RAS optical observations
- GRB 160801A: NOT upper limits
- FACT follow-up of IceCube20160731
- GRB 160801A: Swift-XRT refined Analysis
- Global MASTER net follow up of IceCube-160731A
- Swift follow up of IceCube-160731A
- GRB 160801A: Enhanced Swift-XRT position
- HAWC follow up of IceCube 160731
- GRB160720A: Astrosat CZTI detection
- GRB160709A: Astrosat CZTI detection of short GRB
- 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
- 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
- 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
- GRB 160714A: Swift/UVOT Upper Limits
- GRB 160716A: Enhanced Swift-XRT position
- GRB 160716A: Swift detection of a burst
- Swift Trigger 704327: KAIT Optical Observations
- GRB 160714A: Swift-XRT observations
- 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: MASTER early optical observations
- GRB 160709A CALET Gamma-Ray Burst Monitor detection
- GRB 160714A: Swift-XRT observations
- GRB 160712A: Swift/UVOT Upper Limits
- GRB 160712A: RATIR Optical and NIR Observations
- GRB 160712A: Skynet R-COP observations
- GRB 160712A: Enhanced Swift-XRT position
- GRB 160624A: 15 GHz upper limits from AMI
- GRB 160712A: Swift-XRT observations
- GRB 160712A: Swift detection of a burst
- GRB 160709A: MASTER early imaging Swift BAT error box
- 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)