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"- GRB 140705A: Swift/UVOT Upper Limits
- GRB 140705A: Swift-BAT refined analysis of a possible newly discovered SGR 1935+2154
- GRB 140705A: Enhanced Swift-XRT position
- GRB 140705A: Swift detection of a short burst
- GRB 140621A: Suzaku WAM observation of the prompt emission
- GRB 140629A: SAO RAS Rc band photometry
- GRB 140629A, Optical observations
- GRB 140703A: VLA K-band detection
- GRB 140703A: CARMA 3mm detection
- GRB 140703A: P60 observations of a red, slowly-fading afterglow
- GRB 140703A: RATIR Optical and NIR Observations
- GRB 140703A: Fermi GBM detection
- GRB 140703A: Monte Agliale Observatory optical observations
- GRB 140703A: Swift-XRT refined Analysis
- GRB 140703A: Swift-BAT refined analysis
- Correction to GCN 16507: GRB 140703A!
- GRB 140703A: MASTER optical observations
- GRB 140703A: Enhanced Swift-XRT position
- GRB140703A: 10.4m GTC redshift
- GRB 140703A: BOOTES-2 and OSN optical observations
- GRB 140703A: Swift detection of a burst
- GRB 140619C: Suzaku WAM observation of the prompt emission
- GRB 140629A: MITSuME Akeno Optical observation
- GRB 140629A: MASTER-Net preliminary light curve
- GRB 140629A: SAO RAS monitoring
- GRB 140629A: additional P60 observations
- Fermi 425667201: optical counterpart search
- GRB 140629A: Nishi-Harima NIR Observations
- Konus-Wind observation of GRB 140629A
- GRB 140629A: Swift/UVOT Detection
- GRB 140629A: TNG redshift confirmation
- GRB140629A: VATT optical observations
- GRB 140629A: P60 observations
- GRB 140629A: Swift-XRT refined Analysis
- GRB 140629A: BTA redshift
- GRB 140629A: MITSuME Ishigakijima Optical Observation
- GRB140629A: Kanata/HOWPol optical observation
- GRB 140629A: T100 observations
- GRB 140629A: NOT optical observations
- GRB 140629A: KWFC z-band photometry
- GRB 140629A : Virtual Telescope optical observations
- GRB 140629A: RTT150 optical observations
- GRB 140629A: Swift-BAT refined analysis
- GRB 140629A : Xinglong TNT optical observation
- GRB 140629A: Enhanced Swift-XRT position
- GRB 140629A: MASTER OT detection
- GRB 140629A: Swift detection of a burst with an optical counterpart
- GRB 140628A: GROND observation of the afterglow
- GRB 140628A: Swift-XRT refined Analysis
- GRB 140628A: Zadko observatory - Gingin optical observations
- GRB 140628A: Swift-BAT refined analysis
- GRB 140628A: Swift/UVOT Detection
- GRB 140628A: Swift/UVOT Detection
- GRB 140628A: Swift-XRT afterglow detection and enhanced position
- GRB 140626A: TAROT La Silla observatory optical observations
- GRB 140622A: TAROT La Silla observatory optical observations
- GRB 140628A: Swift detection of a burst
- GRB 140619B: Magellan near-infrared observations
- Swift Trigger 602668: XRT and UVOT confirm is not astrophysical source
- GRB 140623A: further Swift-XRT observations
- Swift Trigger 602668 is probably not an astrophysical source
- GRB 140626A: Swift-BAT refined analysis
- GRB 140626A: Swift-XRT refined Analysis
- GRB 140626A: Swift/UVOT Upper Limits
- GRB 140626A: Enhanced Swift-XRT position
- GRB 140626A: GROND Afterglow Candidate
- GRB 140619B: Suzaku WAM observation of the prompt emission
- GRB 140626A: Swift detection of a burst
- Further Swift/XRT observations of GRB140620A/iPTFcva
- GRB140606B/iPTF14bfu: Keck detection of an associated supernova
- GRB 140620A / iPTF14cva: TShAO optical observations
- GRB 140624A: Fermi GBM observation of a short burst
- GRB 140623A: Swift-XRT and UVOT observations
- GRB 140623A / iPTF14cyb: Fermi GBM detection
- GRB 140621A: Swift-XRT observations
- GRB 140622A: iTelescope.Net T11 Optical Observation
- GRB 140621A: Fermi GBM detection
- GRB 140622A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 140621A
- IPN Triangulation of GRB 140621A
- Konus-Wind observation of GRB 140619A
- Fermi 425193729 / iPTF14cyb: Discovery of optical afterglow
- GRB 140622A: KAIT Optical Upper Limit
- GRB 140620A / iPTF14cva: Konkoly optical observations
- GRB 140622A: Swift-XRT refined Analysis
- GRB 140622A: An unusual short event, Swift-BAT refined analysis
- GRB 140622A: VLT/X-shooter redshift
- GRB 140622A: RATIR Optical and NIR Observations
- GRB 140622A: GROND Upper limits
- GRB 140622A: Enhanced Swift-XRT position
- GRB 140622A: Swift detection of a short burst
- GRB 140620A: Swift/UVOT Detection
- GRB 140606B / iPTF 14bfu: SAO RAS optical observations
- Correction to GCN 16429 (GRB 140619C)
- Konus-Wind observation of GRB 140619C
- GRB 140620A: Swift-XRT observations
- IPN Triangulation of GRB 140619C (long/very intense)
- GRB 140620A / iPTF14cva: Fermi GBM observations
- Fermi 424934131 / iPTF14cva: Discovery and Redshift of Optical Afterglow
- GRB 140619B: Swift-XRT observations