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"19593 results found.
- GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
- GRB080507: Swift/UVOT followup observations
- GRB 080507: Swift-XRT position of a possible afterglow
- GRB 080506: VLA radio upper limit
- GRB 080506: TLS 2nd Epoch - possible light curve break
- GRB 080506: Swift XRT refined analysis
- GRB080506: Swift/UVOT observations
- GRB 080506, Swift-BAT refined analysis
- GRB080503, RIMOTS optical upper limit
- GRB 080506: TLS afterglow detection in VRIZ
- GRB 080506: Enhanced Swift-XRT position
- GRB 080506: Swift detection of a burst with optical afterglow
- GRB 080503, Swift-BAT lag and time-resolved spectral analysis
- GRB080503: Swift/UVOT Upper Limits
- GRB080503 XRT refined analysis
- GRB 080503, Swift-BAT refined analysis
- GRB 080430
- GRB 080503: Enhanced Swift-XRT position
- GRB 080503: Swift detection of a short burst
- GRB 080411: Continued Swift Monitoring
- GRB 080430: Optical observations
- GRB080430: Swift/UVOT observations
- GRB 080430 optical observations
- GRB 080430, Swift-BAT refined analysis
- GRB 080430: Swift-XRT refined analysis
- GRB 080430: Enhanced Swift-XRT position
- GRB 080430 - SDSS Pre-Burst Observations
- GRB 080430: Swift detection of a burst with optical afterglow
- GRB 080430: TAROT Calern observatory optical observations
- GRB 080426: Swift-XRT refined analysis
- GRB080426: Swift/UVOT upper limits
- GRB 080426: Enhanced Swift-XRT position
- GRB 080426, Swift-BAT refined analysis
- GRB 080426: Swift detection of a possibly short burst
- Possible GRB 080315: XRT non-detection of afterglow
- Swift-BAT trigger 309665 is not a GRB
- GRB 080420A: ROTSE-III Optical Limits on a possible short burst
- GRB 080420?: Swift detection of a possible short burst
- GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
- Swift XRT and UVOT observations of GRB080414
- GRB 080319B: Jet Break, Energetics, Supernova
- GRB 080413A: Suzaku WAM observation of the prompt emission
- GRB 080413B: Suzaku WAM observation of the prompt emission
- GRB 080413B: Ep,i-Eiso correlation
- GRB080413B
- Swift-BAT spectral lag analysis of GRB 080413B
- GRB 080413B: Swift XRT refined analysis
- GRB080413A: Swift/UVOT observations
- GRB 080413B, Swift-BAT refined analysis
- GRB 080413A: Swift-XRT refined analysis
- GRB 080413A, Swift-BAT refined analysis
- GRB 080413B: GROND detection of afterglow in all bands
- GRB 080413B: Swift detection of a possibly short burst with optical counterpart
- GRB 080413: Enhanced Swift-XRT position
- GRB 080413: TAROT Calern observatory optical observations
- GRB 080413: Swift detection of a burst with an optical afterglow
- GRB 080413: ROTSE-III Detection of Optical Counterpart
- GRB 080411: Swift/UVOT refined analysis
- GRB 080411, Swift-BAT refined analysis
- GRB 080411: Swift-XRT Refined Analysis
- Konus-Wind observation of GRB 080411
- GRB 080411: Enhanced Swift-XRT position
- GRB 080411: Swift detection of a bright burst
- GRB 080330: Swift-XRT refined position retraction
- GRB 080409: Swift-BAT refined analysis
- Swift/UVOT observations of GRB080409
- GRB 080409: Swift XRT refined analysis
- UVOT/Swift Observations of GRB080408
- GRB 080408: Swift-XRT position of a possible afterglow
- GRB 080409: Enhanced Swift-XRT position
- GRB 080409: Swift detection of a burst
- GRB 080319A: Early RAPTOR optical limits
- GRB 080330: RAPTOR detection of prompt optical flash
- GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
- GRB 080405: Swift-BAT refined analysis
- GRB 080405: Swift-XRT position
- GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
- GRB 080325: optical upper limit
- GRB080330: Improved Swift XRT Position
- GRB080328, RIMOTS optical upper limit
- GRB080330: Swift XRT refined analysis
- GRB 080330 Swift-UVOT refined analysis
- GRB 080328: Suzaku WAM observation of the prompt emission
- GRB 080330, Swift-BAT refined analysis
- Konus-Wind observation of GRB 080328
- GRB 080330: GROND Observations
- GRB 080330: TAROT Calern observatory optical observations
- GRB 080330: error in reported XRT position
- GRB080330 - SDSS Pre-Burst Observations
- GRB 080330: Liverpool Telescope Optical observations
- GRB 080330A: ROTSE-III Detection of Optical Counterpart
- GRB 080330: Swift detection of a burst with an optical counterpart
- GRB 080330: TAROT Calern observatory optical detection
- GRB 080328: BTA optical imaging and spectroscopy
- GRB 080328, Swift-BAT refined analysis
- GRB 080328: Swift XRT refined analysis
- GRB 080325, Swift-BAT refined analysis
- Swift/UVOT observations of GRB080328
- GRB 080328: Enhanced Swift-XRT position
- GRB080328: Faulkes Telescope North observations