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 160629A: Swift-XRT afterglow detection
- GRB 160625B: LCOGT FTN observations
- GRB 160630A: Swift-BAT refined analysis
- GRB 160629A: Global MASTER Net Prompt OT observations
- GRB 160629A: Swift ToO observations
- GRB 160630A: Skynet PROMPT-CTIO observations of the optical afterglow
- Konus-Wind observation of GRB 160629A
- GRB 160630A: Zadko observatory - Gingin optical observations
- GRB 160630A: TAROT La Silla observatory optical observations
- GRB 160629A: BTA and GTC redshift
- GRB 160630A: Swift/UVOT Upper Limits
- GRB 160630A: Swift-XRT refined Analysis
- GRB 160625A: GROND upper limits
- GRB 160629A: Fermi GBM observation
- GRB 160630A: REM NIR observations
- GRB 160630A: Enhanced Swift-XRT position
- GRB 160630A: GROND Afterglow Detection
- GRB 160630A: Swift detection of a burst
- GRB 160629A: SAO RAS independent OT detection
- GRB 160629A: TAROT Calern observatory optical detection
- GRB 160629A: a long GBB detected by INTEGRAL
- GRB 160625B: TSHAO optical observations, correction GCN 19619
- GRB 160625B: TSHAO optical observations
- Konus-Wind observation of GRB 160620A
- GRB 160625B CALET Gamma-Ray Burst Monitor detection
- GRB 160625B: SMARTS optical/IR afterglow observations
- Pi of the Sky detection of an optical flash accompanying GRB 160625B
- GRB 160623A: SAO RAS optical observations
- Konus-Wind observation of a bright burst from SGR 1935+2154
- GRB 160625B: Global MASTER-Net prompt optical emission detection
- GRB 160625B: SAO RAS optical observations
- GRB 160625B: 15 GHz detection from AMI
- GRB 160623A: Possible detection of a radio afterglow at 15 GHz with AMI
- GRB 160601A: 15 GHz upper limits from AMI
- SGR 1935+2154: AMI 15 GHz upper limits of the magnetar during outburst
- GRB 160625B: VLA Detection
- GRB 160625B: TSHAO optical observations
- Konus-Wind observation of GRB 160625B
- GRB 160625B: Mini-MegaTORTORA detection of bright optical flash simultaneous with LAT event
- GRB 160625B: RATIR Optical and NIR Observations
- GRB 160625B: TNG redshift confirmation
- GRB 160625B: VLT/X-shooter redshift
- GRB 160625B: MITSuME Ishigakijima Optical Observation
- Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
- GRB 160623A CALET Gamma-Ray Burst Monitor detection
- Swift-BAT refined analysis on the bright event from SGR 1935+2154
- Swift Trigger 701668 is probably not an astrophysical event
- IPN Triangulation of GRB 160620A (short/hard)
- GRB 160625A: Swift/UVOT Upper Limits
- GRB 160625A: Swift-BAT refined analysis
- GRB 160625A: Swift-XRT refined Analysis
- Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154
- GRB 160625B: Swift/UVOT Detection
- GRB 160625B: RATIR Optical and NIR Afterglow Detection
- GRB 160625B: Fermi GBM refined analysis
- GRB 160625B: Fermi-LAT refined analysis
- GRB 160625B: Swift-XRT afterglow detection
- GRB 160623A: SMA submm afterglow observations
- GRB 160625A: Enhanced Swift-XRT position
- GRB 160625B: Tiled Swift observations
- GRB 160625B: Fermi GBM initial observations
- GRB 160625B: Fermi-LAT detection of a bright burst
- GRB 160625A - two different events?
- GRB 160625A: Swift-XRT observations
- GRB 160625A: Swift detection of a burst
- GRB 160624A: Swift/UVOT Upper Limits
- GRB 160624A: Lulin observation
- GRB 160623A: TSHAO optical observations
- GRB 160624A: Swift-XRT refined Analysis
- GRB 160623A: MITSuME Ishigakijima Optical Observation
- GRB 160624A: MITSuME Ishigakijima upper limits
- GRB 160624A: Fermi GBM observation
- GRB 160624A, Swift-BAT refined analysis
- GRB 160623A: Swift/UVOT Upper Limits
- GRB 160623A: RATIR Optical and NIR Observations, Afterglow Confirmation
- GRB 160624A: Enhanced Swift-XRT position
- GRB160624A:possible GRB host redshift
- GRB 160525B: 15 GHz upper limits from AMI
- GRB 160521B: 15 GHz upper limits from AMI
- GRB 160624A: Prompt enhanced Swift-XRT position
- GRB 160623A: Mondy optical observations
- GRB 160624A: Swift detection of a short burst
- Swift detection of a dust-scattered halo around GRB 160623A
- GRB 160623A: Swift-XRT afterglow detection
- GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
- Trigger 701182: Swift detection of SGR 1935+2154
- GRB 160623A: Fermi GBM detection/observation
- Konus-Wind observation of GRB 160623A
- GRB 160623A / Galactic transient: Fermi-LAT detection
- GRB 160623A: Swift ToO observations
- SGR 1617-5103 (BAT trigger 700791): Enhanced Swift-XRT position.
- Swift-BAT refined analysis of the recent outburst from SGR 1617-5103 (a.k.a. 1E 161348-5055 and 2E 1613.5-5053)
- Fermi GBM Trigger 160622573 is not a GRB
- BAT trigger 700791 (possible GRB 160622A) is SNR RCW 103
- GRB 160622A: Swift detection of a possible short GRB or a new SGR
- More FERMI GBM bursts from the magnetar SGR 1935+2154
- SGR 1935+2154: MAXI/GSC detection
- Fermi GBM trigger 488128598/160620637 is not a GRB
- Fermi GBM trigger 487974449/160618852 is not a GRB
- LIGO/Virgo G211117 / GW151226: Sky maps and other data available in LOSC