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"27400 results found.
- GRB 080408: Swift-XRT position of a possible afterglow
- GRB 080409: Enhanced Swift-XRT position
- GRB 080409: REM optical/NIR observations
- GRB 080409: Swift detection of a burst
- GRB 080408: Analysis of AGILE Gamma-ray data
- GRB 080408: GRB Localization by SuperAGILE
- GRB 080319A: Early RAPTOR optical limits
- GRB 080319B: HST observations
- 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
- GRB 080328: GAO 150cm telescope Optical Observation
- GRB080330: Improved Swift XRT Position
- GRB080330: optical observations
- GRB080328, RIMOTS optical upper limit
- GRB080330: Swift XRT refined analysis
- GRB 080330: REM optical observations
- GRB 080330 Swift-UVOT refined analysis
- GRB 080328: Suzaku WAM observation of the prompt emission
- GRB080330: TNT optical observations
- GRB 080330, Swift-BAT refined analysis
- Konus-Wind observation of GRB 080328
- GRB 080330: GROND Observations
- GRB 080330: TAROT Calern observatory optical observations
- GRB 080330A: PAIRITEL Infrared Detections
- GRB 080330: error in reported XRT position
- GRB080330 - SDSS Pre-Burst 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, Swift-BAT refined analysis
- GRB 080325, Swift-BAT refined analysis
- Swift/UVOT observations of GRB080328
- GRB080319B, BVRcIc field calibration
- GRB 080328: Enhanced Swift-XRT position
- GRB 080328: Swift detection of a burst with an optical counterpart
- GRB 080325: Subaru detection of NIR afterglow candidate
- GRB 080325: GROND Observations
- GRB 080325: Swift/UVOT Upper Limits
- GRB 080325: Early observations from OSN
- GRB 080325: NIR afterglow candidate
- GRB 080319D: GROND Detection of the Optical Counterpart
- GRB 080325: Enhanced Swift-XRT position
- GRB 080325: Swift detection of a burst
- GRB 080319B : Apparent spectral evolution in very early Swift/XRT WT mode data: intrinsic or pile-up effect?
- GRB 080319B: Spitzer Mid-infrared Observations
- GRB 080319C: Suzaku WAM observation of the prompt emission
- Radio Detection of GRB 080319B
- GRB 080320, Swift-BAT refined analysis
- GRB 080319D: GROND Observations
- GRB 080319B: optical upper limit
- GRB 080319D: optical upper limit
- GRB 080319D, Swift-BAT refined analysis
- GRB 080319C: UVOT Observations
- GRB 080319B: UVOT Observations
- GRB 080319A: UVOT Observations
- GRB 080320: Swift XRT refined analysis
- GRB 080320: J detection with FLAMINGOS
- GRB 080319D: Swift XRT refined analysis
- GRB 080320: optical limit
- GRB 080320: Gemini-N optical afterglow
- GRB 080319C, Swift-BAT refined analysis
- GRB 080320: Enhanced Swift-XRT position
- GRB 080320 - SDSS Pre-Burst Observations
- GRB 080320: Swift detection of a burst
- GRB 080319B : Lulin observation of temporal break at 0.2 days
- GRB 080319C - SDSS Pre-Burst Observations
- GRB 080319A SDSS Pre-Burst Observations
- GRB080319B - SDSS Pre-Burst Observations
- GRB 080319A: Swift-XRT Team Refined Analysis
- GRB 080319B, Swift-BAT refined analysis
- GRB 080319C: Swift-XRT Team Refined Analysis
- GRB 080319B: Swift-XRT Team Refined Analysis
- GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
- GRB 080319C: AGILE-MCAL observation of the prompt emission
- GRB 080319D: MASTER-VWF-Kislovodsk optical observation
- GRB 080319C: MASTER-VWF-Kislovodsk optical observation
- GRB 080319D: Swift detection of a burst with a possible optical afterglow
- GRB 080319B: TORTORA synchronous observation
- GRB 080319B: Enhanced Swift-XRT position
- GRB 080319A: Enhanced Swift-XRT position
- GRB 080319A, Swift-BAT refined analysis
- GRB 080319B: REM early data
- GRB 080319C: Swift detection of a burst with an optical afterglow
- GRB 080319A: REM observations
- GRB 080319B: Change in power law decay index
- GRB 080319B: Gemini-South Spectroscopy
- GRB 080319A: optical observations at the NOT
- GRB 080319B: REM observations
- GRB080319A: P60 Optical Afterglow Observations
- GRB 080319B: Swift detection of an intense burst with a bright optical counterpart
- GRB 080319A: Swift detection of a burst
- Swift Trigger 306745 is not a GRB
- Swift Trigger 306616 is not a GRB
- GRB080315: Bok Optical Observations
- Swift/UVOT observations of GRB 080315
- Swift trigger 306323: Swift-BAT/XRT refined analysis
- GRB 080315: Optical observations