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"27321 results found.
- GRB 071118: P60 Observations
- GRB071118 MITSuME OAO optical observation
- GRB 071118: Observations from OSN
- GRB 071117: VLT observations and probable redshift
- Swift/UVOT observations of GRB071118
- Konus-Wind and Konus-A observations of GRB 071117
- Swift XRT follow-up observations of GRB071008
- Swift/UVOT upper limits for GRB 071117
- GRB071118: Swift XRT refined analysis
- GRB 071117: Gemini Optical Afterglow Discovery
- GRB 071118, Swift-BAT refined analysis
- GRB 071117: TAROT La Silla observatory optical observations
- GRB 071118: Swift detection of a burst
- GRB 071117: Gemini Observations
- GRB 071117: Swift-XRT refined analysis
- GRB 071117, Swift-BAT refined analysis
- Swift detection of MXB 0656-072
- GRB 071112C: Optical and NIR data observed with KANATA
- GRB 071112C MITSuME Akeno early optical observation
- GRB 071112C: SARA upper limit
- GRB 071112C : Second Epoch Lulin R-band observations
- GRB071112C MITSuME Okayama Optical Observation
- GRB 071112C: Swift-BAT refined analysis
- GRB 071112C: Swift XRT refined analysis
- Swift UVOT upper limits of GRB071112B
- GRB 071112B: Gemini Optical Imaging
- GRB 071112B: Swift-XRT preliminary analysis
- GRB 071112B, Swift-BAT partial refined analysis of the SHB
- GRB 071112C : Lulin R-band observation
- GRB 071112C: TAROT Calern observatory optical observations
- 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