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"25840 results found.
- 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 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
- GRB080319B Liverpool Telescope optical afterglow candidate
- 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
- GRB080310, LBT and MDM photometry
- GRB080315: Bok Optical Observations
- Swift/UVOT observations of GRB 080315
- GRB 080315: Optical observations
- GRB 080315: TAROT Calern observatory optical observations
- GRB 080315: Swift detection of a possible burst
- GRB 080307: GAO 150cm telescope Optical Observation
- GRB 080229A: GAO 150cm telescope Optical Observation
- GRB 080310, Swift-BAT refined analysis
- GRB 080310: Swift-XRT refined analysis
- GRB 080310: Swift/UVOT Refined Analysis
- GRB 080310 - SDSS Pre-Burst Observations
- GRB 080310: Enhanced Swift-XRT position
- GRB 080310: RRM optical photometry with the VLT
- GRB 080310: REM observations
- GRB 080310: Swift detection of a burst with optical afterglow
- GRB080307, optical upper limit
- GRB080229, optical upper limit
- GRB 080307: Swift-XRT Team refined analysis
- GRB 080307: Swift/UVOT Upper Limits
- GRB 080307, Swift-BAT refined analysis
- GRB080307 - SDSS Pre-Burst Observations
- GRB 080307: TNT optical observation
- GRB080307: Optical upper limits
- GRB 080307: Gemini-N i-band observations - candidate afterglow
- GRB 080307: Enhanced Swift-XRT position
- GRB 080307, Preliminary Swift-BAT refined analysis
- GRB 080307: Optical observation with DMC/KANATA
- GRB 080307: Swift detection of a burst
- VLA possible radio detection of GRB 080229
- GRB080303: Swift XRT refined analysis
- GRB 080303: Enhanced Swift-XRT position
- Swift UVOT observations of GRB080229B
- GRB080229B: Swift XRT afterglow observation
- GRB 080303A: Faulkes Telescope South optical afterglow observations
- GRB 080303: Swift detection of a burst with optical afterglow
- GRB 080303: REM NIR afterglow candidate
- GRB 080303A: ROTSE-III Optical Limits
- GRB 080229: I-band observations from OSN
- GRB 080229: VLT NIR observations
- GRB080229: Swift XRT refined analysis
- GRB 080229: TNG NIR observations
- GRB 080229: Enhanced Swift-XRT position
- GRB 080229: REM NIR observations
- GRB080229: Possible optical afterglow
- GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
- UVOT analysis for GRB080229
- GRB 080229: Faulkes Telescope South optical limit
- GRB 080229A: ROTSE-III Optical Limits
- GRB 080229: Swift detection of a bright burst
- XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
- GRB 071010B : Early optical brightening detected by TAOS
- Swift-XRT improved positions, and new redshift limits.
- ESO optical and NIR observations of GRB 080218B
- GRB 080204: Suzaku WAM observation of the prompt emission
- GRB 080218B: Swift-XRT refined analysis
- Swift/UVOT observations of GRB080218B
- GRB 080218B: REM NIR early upper limits
- GRB 080218B: Enhanced Swift-XRT position
- GRB 080218B: GROND upper limits
- GRB 080211: Suzaku WAM observation of the prompt emission
- Swift-XRT and UVOT observations of the IPN burst GRB 080211
- GRB 080212: REM refined analysis
- Konus-Wind observation of GRB 080211
- VLA radio upper limit on GRB 080212
- Swift/UVOT refined analysis of GRB080212
- GRB080212: Optical afterglow candidate observed by MITSuME Telescope
- GRB 080212: GROND detects afterglow
- GRB 080212: REM NIR afterglow?
- GRB 080212: Enhanced Swift-XRT position
- GRB 080212: Swift-XRT Team refined analysis
- GRB 080210: Keck photometry
- VLA non-detection of GRB 080210
- GRB 080212: Swift detection of a burst
- IPN localization of GRB 080211
- GRB 080207: VLT NIR early upper limits
- GRB 080210: Swift/UVOT Refined Analysis
- GRB 080210: Super-LOTIS observations
- GRB 080210: Swift-XRT Refined Analysis