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"27030 results found.
- GRB 080319B: Swift-XRT Team Refined Analysis
- GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
- 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 080319A, Swift-BAT refined analysis
- GRB 080319C: Early Super-LOTIS Observations
- GRB 080319C: Swift detection of a burst with an optical afterglow
- GRB 080319C: KAIT OA candidate
- GRB 080319B: Change in power law decay index
- GRB 080319B: Gemini-South Spectroscopy
- GRB080319B Liverpool Telescope optical afterglow candidate
- GRB 080319B: Super-LOTIS Detection of a Bright OT
- GRB 080319B: KAIT OA
- 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
- Swift/UVOT observations of GRB 080315
- Swift trigger 306323: Swift-BAT/XRT refined analysis
- SAX J1818.6-1703: Swift detection (trigger 306379)
- GRB 080315: TAROT Calern observatory optical observations
- GRB 080315: Swift detection of a possible burst
- GRB 080310: ROTSE-III Observations of Optical Counterpart
- GRB080310: Optical observation by MITSuME telescope
- GRB 080310: early RAPTOR multicolor observations
- 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: VLT/UVES spectroscopy
- GRB080310: Super-LOTIS suggestion of brightening
- GRB 080310: Swift detection of a burst with optical afterglow
- GRB080229, optical upper limit (Correction)
- GRB080307, optical upper limit
- GRB080229, optical upper limit
- GRB 080307: Swift-XRT Team refined analysis
- GRB 080307: Swift/UVOT Upper Limits
- GRB 080307: Early RAPTOR Limits
- GRB 080307, Swift-BAT refined analysis
- GRB080307 - SDSS Pre-Burst Observations
- GRB 080307, Preliminary Swift-BAT refined analysis
- GRB 080307: Swift detection of a burst
- GRB 080303: Swift/UVOT follow-up of afterglow detection
- GRB 080303, Swift-BAT refined analysis
- GRB080303: Swift XRT refined analysis
- 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 080303A: ROTSE-III Optical Limits
- GRB080229: Swift XRT refined analysis
- GRB080229: Possible optical afterglow
- UVOT analysis for GRB080229
- GRB 080229, Swift-BAT refined analysis
- GRB 080229: Faulkes Telescope South optical limit
- GRB 080229A: ROTSE-III Optical Limits
- GRB 080229: Swift detection of a bright burst
- Swift-XRT improved positions, and new redshift limits.
- GRB 080204: Suzaku WAM observation of the prompt emission
- GRB 080218B, Swift-BAT refined analysis
- GRB 080218B: Swift-XRT refined analysis
- Swift/UVOT observations of GRB080218B
- GRB 080218B: GROND upper limits
- GRB 080218A, Swift-BAT refined analysis
- GRB 080211: Suzaku WAM observation of the prompt emission
- GRB 080218B: Swift detection of a burst
- GRB 080218: Swift detection of a burst
- Swift-XRT and UVOT observations of the IPN burst GRB 080211
- Swift/UVOT refined analysis of GRB080212
- GRB 080212, Swift-BAT refined analysis
- GRB080212: Optical afterglow candidate observed by MITSuME Telescope
- GRB 080212: GROND detects afterglow
- GRB 080212: optical observations
- GRB 080212: Swift-XRT Team refined analysis
- GRB 080210: Keck photometry
- GRB 080212: Swift detection of a burst
- GRB 080212: DSS/2MASS Galaxy at XRT position
- GRB 080210: Swift/UVOT Refined Analysis
- GRB 080210, Swift-BAT refined analysis
- GRB 080210: Super-LOTIS observations
- GRB 080210: Swift-XRT Refined Analysis
- GRB 080210: Rapid PROMPT Detections
- GRB 080210: GOND detection in all bands and redshift upper limit
- GRB080210 - SDSS Pre-Burst Observations
- GRB 080210: Swift detection of a burst with optical afterglow
- GRB 080210: TAROT La Silla observatory optical detection
- GRB 080207, Swift-BAT refined analysis
- GRB 080207: Optical limits from Gemini-South
- Swift detection of AX J1749.1-2639
- GRB 080207: Super-LOTIS observations
- GRB 080207, Swift-BAT refined analysis
- Swift Trigger 302777 is not a GRB
- GRB080207: RTT150 Optical Observations
- GRB080207: Swift/UVOT refined analysis
- GRB 080207: TAROT Calern observatory optical observations
- GRB 080207: Swift detection of a burst
- GRB 080205, Swift-BAT refined analysis
- GRB 080205: Swift XRT refined analysis
- GRB 080205: OA evolution from KAIT observations