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"19530 results found.
- GRB 071003: KAIT optical afterglow observations
- GRB 071003: Swift detection of a bright burst
- GRB 070714B: host galaxy spectroscopic redshift
- GRB 071001: Swift-XRT Team refined analysis
- GRB 071001, Swift-BAT refined analysis
- Faulkes Telescope South observations of GRB 071001
- GRB 071001: Swift detection of a burst
- VLA observation of GRB 070923
- Disregard the Swift-XRT Notices today
- GRB070925: Swift-XRT Afterglow confirmation
- GRB070925: Swift-XRT Position
- Update on Swift Status
- GRB 070920B: ROTSE-III Early Optical Limits
- Recent SGR1806-20 Activity
- GRB 070923, Swift-BAT refined analysis
- GRB 070920B: XRT observations
- GRB 070923: Swift detection of a short hard burst
- GRB 070917: Suzaku/WAM observation of the prompt emission
- GRB 070920B: TAROT La Silla observatory optical observations
- GRB 070917: Confirmation of the X-ray afterglow
- GRB 070920B, Swift-BAT refined analysis
- GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
- GRB 070920B: NOT optical observations
- GRB 070920B: Swift detection of a burst
- GRB 070920, Swift-BAT refined analysis
- GRB 070920: TAROT Calern observatory optical observations
- GRB 070920: Swift detection of a burst
- SGR1806-20: Swift-BAT detection of enhanced activity
- GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
- Konus-Wind observation of GRB 070917
- Swift Status and XRT Calibration Uncertainties
- GRB 070917: Swift-XRT observations
- GRB 070917: KAIT optical limits
- GRB 070917: R band observations
- GRB 070917, Swift-BAT refined analysis
- GRB 070917: Swift detection of a bright burst
- GRB 070911: Suzaku WAM observation of the prompt emission
- GRB 070913: Swift-XRT detection of the possible X-ray afterglow
- GRB 070809: The Swift evidence for the SHB nature of this burst
- GRB 070913: Swift-BAT refined analysis
- GRB 070913: Corrected BAT position
- GRB 070913: TAROT La Silla observatory optical observations
- GRB 070913: Swift detection of a burst
- Swift-BAT Notices back to autonomous real-time distribution
- GRB 070911: Swift XRT refined analysis
- GRB 070911, Swift-BAT refined analysis
- GRB 070911: Swift detection of a burst
- IPN search for a GRB associated with TAROT transient on August 31
- Intense burst from SGR 1806-20 detected on September 7
- GRB 070824 - Combined SuperAGILE/IPN Localization
- GRB 070731: Swift/UVOT Upper Limit
- GRB 070805: UVOT afterglow candidate retraction
- GRB070810b: optical candidate
- GRB 070810A: ROTSE-III Refined Analysis
- Swift observatory off line
- GRB070810B: Swift/UVOT Upper Limits
- GRB 070810B: XRT refined analysis
- GRB 070810B, Swift-BAT refined analysis
- GRB 070809: Swift/UVOT Corrected Photometry
- Swift Alert 070810.8: MASTER optical observation
- Swift Trigger 287421: False trigger due to star tracker loss
- GRB 070810A: Swift-BAT refined analysis
- GRB 070809: Swift/UVOT Upper Limits
- GRB 070810B: Swift detection of a short burst
- VLA upper limit on the short hard burst GRB 070729
- No radio detection in superAGILE burst 070724B
- GRB 070810: Swift-XRT Team Refined Analysis
- GRB 070809: Swift-XRT refined analysis
- GRB 070810: enhanced Swift-XRT position
- GRB 070810: Swift/UVOT Optical Counterpart
- GRB 070810: ROTSE-III Detection of Optical Counterpart
- GRB 070810: Swift detection of a burst
- GRB 070809, Swift-BAT refined analysis
- GRB 070808: Swift/UVOT upper limits
- GRB 070809: ROTSE-III Optical Limits
- GRB 070809: Swift detection of a short burst
- GCN Swift XRT update position notices and enhanced position circulars
- GRB 070808: Swift XRT refined analysis
- GRB 070808, Swift-BAT refined analysis
- GRB070808 - SDSS Pre-Burst Observations
- GRB 070808: ROTSE-III Optical Limits
- GRB 070808: Swift detection of a burst
- GRB070805 XRT and UVOT afterglow candidate
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- Swift/UVOT observations of GRB070805
- GRB 070805, Swift-BAT refined analysis
- GRB 070805: Swift XRT initial analysis.
- GRB 070805: Swift/UVOT initial analysis
- GRB 070805: Swift detection of a burst
- UVOT observations of SAXJ1810.8-2609
- Swift detection of a outburst from SAX J1810.8-2609
- VLA non-detection of GRB 070721B
- GRB 070802: REM optical observations
- GRB 070724B: Swift-XRT afterglow confirmation
- GRB 070802: Swift-XRT refined analysis
- GRB070802: Swift/UVOT upper limits
- GRB 070802, Swift-BAT refined analysis
- GRB 070802: refined Swift XRT position
- GRB 070802: GROND J band candidate
- GRB 070802: Swift detection of a burst