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"7293 results found.
- GRB 061028: Optical R passband observations
- GRB 061102: Swift detection of a burst
- GRB 061028: Futher P200 Observations
- GRB 061028: P200 Observations
- GRB 061028: Swift detection of a burst
- GRB 061027, Swift refined analysis of a possible burst
- GRB 061027: Swift detection of a possible burst
- GRB061025: ROTSE-III Confirmation of Optical Counterpart
- GRB 061025: REM observations
- GRB 061025: Gemini-S observations
- GRB 061021: Swift detection of a burst
- GRB 061019: SARA upper limit
- GRB061019: Swift XRT refined analysis
- GRB 061019: REM K-band candidate afterglow
- GRB 061006: astrometry-corrected XRT position
- GRB 061007: ROTSE-III Detection of Optical Counterpart
- GRB 060930: near-IR afterglow candidate retraction
- GRB 061004: Optical afterglow candidate and redshift
- GRB 061004: Swift detection of a burst
- GRB 060930: near-IR afterglow candidate
- GRB 061002: Swift detection of a burst: CORRECTED CONTENT
- GRB 061002: Swift detection of a burst
- GRB 060929: Swift detection of a burst
- GRB 060927: Swift XRT Team refined analysis
- GRB060927: Faulkes Telescope South observation
- GRB 060927: Swift detection of a burst
- GRB 060926: RTT150, UVOT afterglow candidate confirmation
- GRB 060926: MASTER optical observation
- GRB 060926: Swift detection of a burst
- GRB 060923C: Gemini Observations and Afterglow Candidate
- GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
- GRB 060923A: Swift XRT refined analysis
- GRB 060923A: Keck and Gemini Observations
- GRB 060923C: optical observation
- GRB 060923B: Swift detection of a burst
- GRB 060923: UKIRT nIR observations - candidate afterglow
- GRB 060923: Swift detection of a burst
- GRB 060919: Swift detection of a burst
- GRB060912: optical observations
- GRB 060912: Swift detection of a burst with an optical afterglow
- GRB 060908: Swift detection of a burst with a bright optical counterpart
- GRB 060906: KAIT observations
- GRB 060906: Confirmation of P60 Optical Afterglow
- GRB 060906: observations with FRAM
- GRB 060906 (?): P60 Optical Afterglow Candidate
- GRB 060906: Swift detection of a probable burst
- GRB 060904B: Swift detection of a burst with optical counterpart
- GRB 060904: Swift detection of a bright burst
- GRB 060826(?): Swift detection of a possible burst
- GRB 060825: TAROT optical observations
- GRB 060825: Swift detection of a burst
- GRB060801: host galaxy redshift
- GRB 060814: Swift detection of a bright burst
- GRB 060813: Swift detection of a burst
- GRB 060807: K- and R-band observations
- GRB060807: optical afterglow candidate
- GRB060807: optical upper limit in white light
- GRB 060805B: Swift/UVOT Upper Limits
- GRB 060807: Swift detection of a burst
- GRB 060805: optical upper limit in R
- GRB 060805: Swift/UVOT Upper Limits
- GRB 060805: Swift detection of a burst
- GRB 060804: Swift UVOT observations
- GRB 060804: Swift detection of a burst with a possible UVOT counterpart
- GRB060801: optical upper limit in R
- GRB 060801: Swift detection of a short burst
- GRB060719: prompt NIR observations with REM
- GRB 060719: prompt PROMPT observations
- GRB 060719: Continued LCO optical observations
- GRB 060719: Swift detection of a burst
- GRB 060717 optical upper limit
- GRB 060714: REM infrared observations
- GRB 060717: Swift detection of a burst
- GRB 060714 : Liverpool Telescope Observations
- GRB 060714: OA redshift
- GRB 060708: VLT spectroscopy
- GRB060714: optical observations
- GRB 060714: Swift detection of a burst with an UVOT optical afterglow
- GRB060712: MASTER optical observation
- GRB120706: MASTER optical observation
- GRB 060707: Swift-XRT refined analysis
- GRB 060708: Swift detection of a burst with an UVOT countpart
- GRB 060707: BOOTES-IR optical afterglow candidate
- GRB 060707: Swift detection of a burst
- GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
- GRB060602A: Swift/UVOT upper limits
- GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
- GRB 060607: Swift detection of a burst with bright optical counterpart
- GRB060605: Spectral Observations and Redshift
- GRB 060605: Swift detection of a burst with optical counterpart
- GRB060604: Swift/UVOT detections
- GRB 060604: redshift
- GRB 060604: Swift detection of a burst with possible optical counterpart
- GRB 060602B: Swift detection of a burst
- GRB060602B: Watcher observations - no OT candidate
- GRB060602B: BOOTES-IR candidate afterglow
- GRB 060526: Continued emission for the Swift burst
- GRB 060526: Swift detection of a burst with x-ray and optical afterglow
- GRB 060522: REM NIR observations
- GRB 060522: TNG optical observations