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"20514 results found.
- GRB 101225A: HST observations - no host detected
- GRB 101225A: Redshift retraction and results of additional photometric follow-up at the NOT
- GRB 110112A: WHT candidate afterglow/host galaxy
- GRB 110112A: MASTER optical observations
- GRB 110106B: MASTER optical observations
- GRB110112A: TNT optical afterglow candidate
- GRB 110106B: early optical and near-IR observations
- GRB 101225a
- GRB 101219b. Possible radio afterglow detection.
- GRB 110106B: MASTER early optical observations
- GRB 110107A: Swift-XRT Afterglow Candidate
- GRB 110107A: Swift-BAT refined analysis
- Short GRB 110106A: MASTER OT observations
- GRB 110106B: Gemini-North / WHT detection of a fading afterglow
- GRB 110106A: TNG NIR observations
- GRB 110106B: Liverpool Telescope observations
- GRB 110106B: WHT candidate afterglow
- GRB 110106A: Swift/UVOT Upper Limits
- GRB110106B: Xinglong TNT upper limit
- GRB 110106A: TNG optical observations and candidate counterparts
- GRB 110106A: MASTER optical observations
- GRB 101225A: Keck redshift
- GRB110106A: Xinglong TNT upper limit
- GRB 101225A: Host galaxy
- GRB 101219A: Gemini-North host redshift
- GRB 101219B: After 2 weeks still detected by Swift/UVOT
- GRB110102A: Swift/UVOT observations
- GRB 101225A: MMT spectroscopy
- GRB 101225A: P60 Observations
- GRB 101225A: MAXI/GSC observations
- GRB 101225A Late-time emission observed by Swift-BAT
- GRB 101225: Optical follow-up of the Christmas burst
- GRB 101225A: WHT observations
- Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
- GRB 101225A: Swift/UVOT Detection
- Trigger 441015 / GRB 101225A: Further NOT optical observation
- GRB 101224A: NOT optical observation
- GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
- GRB 101224A: Swift/UVOT Upper Limits
- GRB 101219A: Chandra Observations
- GRB 101219B: Swift/UVOT refined analysis
- GRB 101219B: GROND Detection of the Optical/NIR Afterglow
- GRB 101219A: IAC80 optical observations
- GRB 101219A: Swift/UVOT Upper Limits
- GRB 101219A: GROND Upper limits
- GRB 101219A: Magellan NIR observations
- GRB 101219A: Further Gemini-South Imaging
- GRB 101219A: Gemini-South observations
- GRB 101219A: REM optical and NIR observations
- GRB 101213A: Swift/UVOT Upper Limits
- GRB101204A: Swift/UVOT observations
- GRB101204A GROND Detection of the Optical/NIR Afterglow
- GRB 101204A Afterglow Candidate, VATT Observations
- GRB 101204A Swift-XRT/UVOT afterglow candidate
- GRB 101129A SHB found by IPN and in ground analysis of BAT data
- GRB 101201A: Swift/UVOT Detection
- GRB 101201A: GROND Detection of the Optical/NIR Afterglow
- GRB 101123A: ROTSE optical observations
- GRB 101123A: MASTER prompt optical observations
- Optical observation of GRB 101024A
- GRB 101117B: GROND Upper limits
- GRB 101117B: Swift/UVOT Observations of the Optical Afterglow
- GRB 101112A: OSN and BTA observations
- XRF 101117A: Palomar Transient Factory Observations
- GRB101114A: Swift/UVOT Upper Limits
- XRF101117A: MAXI/GSC detection of a short X-ray transient
- GRB 101114A: GROND Upper limits
- Possible detection of INTEGRAL burst GRB 101112A by the EVLA
- GRB 101112A: optical observations
- GRB 10112A: MASTER optical observations
- GRB 101112A: BOOTES-2/TELMA optical afterglow candidate
- GRB 100906A: optical observations
- GRB 101030A : MOA optical observation
- GRB 101030A: GROND optical/NIR afterglow candidate
- GRB 101030A: Swift/UVOT Upper Limits
- GRB 090111, the review of the sky area in plate archives (1976-1996)
- GRB 101024A: GROND optical/NIR observations
- GRB 101024A: Zadko observatory - Gingin. Optical observations refined analysis
- GRB 101024A: Zadko observatory - Gingin. Optical observations
- GRB 101023A: miniTAO/ANIR NIR detection
- GRB101024A: Swift/UVOT
- GRB 101024A: GRAS06 optical observations
- Swift/UVOT observations of GRB101023A
- GGRB 101023A: GROND detection of the optical-NIR afterglow
- GRB 101023A: Gemini discovery of optical afterglow
- GRB 101023A: REM NIR observations
- GRB 101020A: MASTER polarization optical observations
- GRB 101017A: miniTAO/ANIR NIR upper limits
- GRB 101017A: Swift/UVOT Observations
- GRB 101008A: optical observations
- GRB 101011A: BOOTES-3 Upper Limit
- GRB 101011A: Swift/UVOT observations
- GRB 101011A, GROND upper limits
- GRB 101011A: Zadko observatory - Gingin optical observations
- GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
- GRB 101008A: MASTER prompt optical observations (correction to GCN#11328)
- GRB 101008A: MASTER prompt optical observations
- GRB101008A, GROND detection of a fading afterglow
- GRB 101008A: SAO RAS optical observations
- GRB 101008: Swift/UVOT Upper Limits