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.
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 071021: possible high-z burst
- GRB 071021, Swift-BAT refined analysis
- GRB071018: 2nd epoch obsevations of Xinglong TNT
- GRB 071021: retraction of Faulkes Telescope South candidate
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071021: Xinglong TNT optical Upper Limit
- GRB 071021 : Lulin R-band limit
- Konus-Wind observation of GRB 071020
- GRB 071021: Faulkes Telescope South optical candidate
- GRB 071021: Swift detection of a burst
- GRB 071010B: Independent Confirmation of Break
- 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: VLT spectroscopy
- 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
- GRB071010b: optical observations
- GRB 071018: SARA observations
- GRB 071018: Swift-XRT observation
- GRB 071017 - Swift XRT observations
- VLA radio observation of GRB 071018
- GRB071018: Correction to the GCN 6936
- GRB071018: Correction to the GCN 6936
- GRB071018: Correction to the GCN 6936
- GRB071018: Correction to the title of the GCN 6936
- 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 071018?: Swift detection of a possible burst
- GRB 071010B: Suzaku WAM observation of the prompt emission
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071013: TNT optical data refined analysis
- GRB 071010B: Keck/DEIMOS emission-line redshift
- GRB 071017: a SHORT GRB detected by INTEGRAL
- GRB 071013: TLS 2nd epoch - Kornienko candidate constant
- GRB071013: optical observations
- GRB 071010B: Optical observations of EST
- GRB 071010B: TLS 3rd Epoch - finally a break??
- GRB 071011: MITSuME Optical Observations
- GRB 070920A: deep optical observations at the NOT
- GRB 071010B: Photometry after 1.6 days
- GRB 071010B: Keck/LRIS Photometry
- GRB 071010B: TLS 2nd Epoch, refined analysis
- GRB 071013: TLS Upper Limit
- Correction to GCN circular no. # 6915 for GRB 071010B
- VLA detection of radio afterglow of GRB 071010B
- VLA non-detection of GRB 071011
- GRB 071013: Optical observations
- GRB 071013: optical observations at NOT
- GRB 071013, Swift-BAT refined analysis
- GRB071013: optical limit
- GRB071010B, BVRcIc field calibration
- GRB 20071013: Xinglong TNT optical Upper Limit
- GRB 071013: Swift detection of a burst
- GRB 071010C Swift-BAT detection of a burst
- GRB 071011: Optical Limit after 13.95hrs
- GRB 071011: Xinglong TNT Optical afterglow observations
- GRB 071010B correction to GCN 6892 optical observations
- GRB 071011: Swift-XRT refined analysis
- VLA non-detection of GRB 071010A
- GRB 071011: NAYUTA Optical Observation, correction to GCN6886
- GRB 071011, Optical afterglow
- GRB 071011: Confirmation of P60 optical afterglow
- GRB 071010B: Optical Detection
- GRB 071011: Kanazawa Optical limits
- GRB 071011: P60 Optical Afterglow Candidate
- GRB 071011: MARGE Optical Limits
- GRB 071010B: Super-LOTIS upper limit
- GRB 071010B optical photometry
- GRB 071011: XRT afterglow detection
- GRB 071010B: Keck/LRIS Spectroscopy
- GRB 071011, Swift-BAT refined analysis
- GRB 071010B: Gemini Spectroscopic Observations
- GRB 071011: Early Super-LOTIS Observations
- GRB 071011: NAYUTA Optical Observation
- GRB 071010A: Continued Keck Imaging
- GRB 071010B: Bright OT confirmed with TLS
- GRB 071011: Optical afterglow candidate
- GRB 071011: Swift detection of a burst
- Optical Observation: GRB 071010
- Optical observations: GRB 071010A
- Konus-Wind observation of GRB 071010B
- GRB071010B: Swift/XRT detection
- GRB 071010B, Swift-BAT refined analysis
- GRB 071010A: bright NIR afterglow
- GRB 071006, Swift-BAT refined analysis
- GRB071008: optical observations
- GRB 071010B possible optical transient
- GRB 071010A: Keck/LRIS Photometry
- GRB 071010B: Swift detection of a burst
- GRB 071010: Swift-XRT observation
- GRB 071008, Swift-BAT refined analysis
- GRB 071010, Swift-BAT refined analysis