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"27391 results found.
- Swift XRT follow-up observations of GRB071028B
- GRB071112C Xinglong_TNT_and_EST_afterglow observations
- GRB 071112C: Optical and NIR afterglows observed with KANATA
- GRB 071112C: Swift detection of a burst with an optical counterpart
- GRB 071112B: Swift detection of a short hard burst
- GRB 071112: Swift detection of a possible burst
- Swift/UVOT initial analysis of GRB071109
- GRB 071109: further Swift-XRT analysis
- GRB 071109: TAROT Calern observatory optical observations
- GRB 071109: Swift-XRT possible X-ray counterpart
- GRB 071109: IBIS refined analysis
- GRB 071104: Swift-XRT Team Refined Analysis
- GRB 071104: Possible Swift UVOT Afterglow Candidate
- GRB 071104: Swift-XRT position
- GRB 071104: Gamma Ray Burst Localization by SuperAGILE
- Swift XRT and UVOT observations of GRB071028B
- GRB 071101, Swift-BAT refined analysis
- GRB 071101: Swift-XRT Team refined analysis
- GRB071101: Optical and NIR upper limits by KANATA
- GRB0711101: Two new source from Xinglong TNT observation
- GRB 071101: TAROT Calern observatory optical observations
- GRB071101 LOAO B,V,R,I observation
- GRB 071101: Swift detection of a burst
- GRB 071031, Swift-BAT refined analysis
- GRB 071031: Swift-XRT Team refined analysis
- GRB 071020: MITSuME Akeno optical observations
- GRB 071031: REM NIR and Optical observation
- GRB 071031: Swift detection of a burst with an optical counterpart
- GRB 071028B Swift-BAT detection of a burst
- GRB 071028: SARA observations of variable source
- Swift UVOT upper limits to GRB071028
- GRB071028: Xinglong EST V-band upper limit
- GRB 071028: Swift-XRT Team refined analysis
- GRB 071028, Swift-BAT refined analysis
- GRB 071028: Swift detection of a burst
- GRB 071003: Infrared Photometry with Keck Adaptive Optics
- GRB071021: MARGE Optical Limits
- GRB071020, optical upper limit
- GRB 071025: SARA VRI upper limits
- Swift UVOT upper limits
- GRB071025: Xinglong TNT I-band upper limit
- GRB 071025: Swift-XRT Team refined analysis
- GRB 060602A: host redshift
- GRB 071025, Swift-BAT refined analysis
- GRB071021 : CFHT Ks-band observation
- GRB 071025: ROTSE-III Refined Analysis
- GRB 071025a: PAIRITEL observations
- GRB 071025: ROTSE-III Detection of Optical Counterpart
- GRB 071025: Swift detection of a burst
- GRB 071021: R-band detection and analysis
- Possible radio detection of GRB 071021 with the VLA
- GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
- GRB 071020: SARA observations
- Radio detection of GRB 071020 with the VLA
- GRB071021: MITSuME Okayama Optical Upper Limits
- GRB 071021: Z-band detection
- GRB 071021: optical and NIR observations
- GRB 071021: possible high-z burst
- GRB 071021, Swift-BAT refined analysis
- GRB071018: 2nd epoch obsevations of Xinglong TNT
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071021: Xinglong TNT optical Upper Limit
- GRB 071021 : Lulin R-band limit
- GRB 071021: Swift detection of a burst
- GRB071020A: Xinglong TNT Optical afterglow observations
- GRB 071020: Swift-XRT refined analysis
- GRB 071020, Swift-BAT refined analysis
- GRB 071020A: IR Imaging with PAIRITEL
- GRB 071020: ROTSE-III Analysis of Optical Counterpart
- GRB071020 - SDSS Pre-burst Observations
- GRB 071020: Swift detection of a bright burst
- GRB 071020A: ROTSE-III Detection of Optical Counterpart
- GRB 071018: Mercator Telescope optical observations
- Swift autonomous slewing re-enabled
- GRB 071018: SARA observations
- GRB 071018: Swift-XRT observation
- GRB 071017 - Swift XRT observations
- GRB 071018: Possible OT from Xinglong TNT observation
- GRB 071010B: Light Curve Break Confirmed
- GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
- GRB 071018, Swift-BAT refined analysis
- GRB 071010B: Suzaku WAM observation of the prompt emission
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071013: TLS 2nd epoch - Kornienko candidate constant
- GRB 071010B: Optical observations of EST
- GRB 071011: MITSuME Optical Observations
- GRB 070920A: deep optical observations at the NOT
- GRB 071010B: Keck/LRIS Photometry
- GRB 071013: TLS Upper Limit
- VLA non-detection of GRB 071011
- GRB 071013: Optical observations
- GRB 071013: optical observations at NOT
- GRB 071013, Swift-BAT refined analysis
- GRB071010B, BVRcIc field calibration
- GRB 20071013: Xinglong TNT optical Upper Limit
- GRB 071010C Swift-BAT detection of a burst
- GRB 071011: Optical Limit after 13.95hrs
- GRB 071010B correction to GCN 6892 optical observations
- GRB 071011: Swift-XRT refined analysis
- VLA non-detection of GRB 071010A