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"7397 results found.
- GRB 080330: Liverpool Telescope Optical observations
- GRB 080330: Swift detection of a burst with an optical counterpart
- GRB 080330: TAROT Calern observatory optical detection
- GRB080325 - I and z-band Imaging
- GRB 080328: Swift detection of a burst with an optical counterpart
- GRB 080325: Subaru detection of NIR afterglow candidate
- GRB 080325: MITSuME Akeno optical upper limits
- GRB 080325: GROND Observations
- GRB 080325: Swift/UVOT Upper Limits
- GRB 080325: NIR afterglow candidate
- GRB 080325: Swift detection of a burst
- GRB 080319D: optical upper limit
- GRB 080320: Early Super-LOTIS Observations
- GRB 080320: Swift detection of a burst
- GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
- GRB 080319D: Swift detection of a burst with a possible optical afterglow
- GRB 080319C: Swift detection of a burst with an optical afterglow
- GRB 080319C: KAIT OA candidate
- GRB080319B Liverpool Telescope optical afterglow candidate
- GRB 080319B: Super-LOTIS Detection of a Bright OT
- 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/UVOT observations of GRB 080315
- GRB 080315: Swift detection of a possible burst
- GRB 080307: NIR upper limit
- GRB 080310 afterglow candidate (correction to UT time)
- GRB 080310: Swift detection of a burst with optical afterglow
- GRB 080310 afterglow candidate
- GRB 080307: TNT optical observation
- GRB 080307: Gemini-N i-band observations - candidate afterglow
- GRB 080307: retraction of UVOT candidate
- GRB 080307: Optical observation with DMC/KANATA
- 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 080229: VLT NIR observations
- GRB 080229: TNG NIR observations
- GRB 080229: REM NIR observations
- GRB 080229: Faulkes Telescope South optical limit
- GRB 080229: Swift detection of a bright burst
- GRB 080218B: REM NIR early upper limits
- GRB 080218B: Swift detection of a burst
- GRB080212: Optical afterglow candidate observed by MITSuME Telescope
- GRB 080212: Swift detection of a burst
- GRB 080207: VLT NIR early upper limits
- GRB 080210: VLT redshift
- GRB 080210: Swift detection of a burst with optical afterglow
- GRB 080210: TAROT La Silla observatory optical detection
- GRB080207: RTT150 Optical Observations
- GRB 080207: REM NIR observations
- GRB 080207: Swift detection of a burst
- GRB 080205: Swift detection of a burst
- GRB 080129: KAIT optical limits
- GRB 080129: Gemini-South photometry
- GRB 080129 (?): UVOT Upper Limits
- GRB 080121: Upper limit on X-ray afterglow
- GRB 080123: Swift detection of a short burst
- GRB 071227: optical afterglow
- GRB 071227: Magellan redshift confirmation
- GRB 071227: VLT probable redshift of the candidate host galaxy
- GRB071227: Swift/UVOT refined analysis
- GRB 071227: REM NIR and Optical observations
- GRB 071227: Swift detection of a burst
- GRB 070429B: Possible UVOT Detection of an Optical Afterglow
- GRB071104: NIR Afterglow Candidate at TNG
- GRB 071122: MASTER optical observation
- GRB 071122: Corrected P60 Coordinates
- GRB 071122: P60 Optical Afterglow Candidate
- GRB 071122: Swift detection of a burst
- GRB 071117: TAROT La Silla observatory optical observations
- GRB 071118: Swift detection of a burst
- GRB 071117: Initial Swift/UVOT observations
- Swift detection of MXB 0656-072
- GRB 071112B: Gemini Optical Imaging
- GRB 071112C: Swift detection of a burst with an optical counterpart
- GRB 071112: Swift detection of a possible burst
- GRB071109: Super-LOTIS observations
- GRB 071109: further Swift-XRT analysis
- GRB 071104: Possible Swift UVOT Afterglow Candidate
- GRB071101: Optical and NIR upper limits by KANATA
- GRB 071101: Swift detection of a burst
- GRB 071031: REM NIR and Optical observation
- GRB 071031: Swift detection of a burst with an optical counterpart
- GRB 071028: SARA observations of variable source
- GRB 071028: Swift detection of a burst
- GRB 071025: Swift detection of a burst
- GRB 071021: R-band detection and analysis
- GRB071021: Optical+NIR observations
- GRB 071021: Subaru NIR observation
- GRB 071021: retraction of Faulkes Telescope South candidate
- GRB 071021: Swift-XRT Team refined analysis
- GRB 071021 : Lulin R-band limit
- GRB 071021: Faulkes Telescope South optical candidate
- GRB 071018: SARA observations
- GRB 071013: 3rd TLS Epoch - constraints on variability
- GRB 071013: TLS 2nd epoch - Kornienko candidate constant
- GRB 071013: Optical observations
- GRB 071013: optical observations at NOT
- GRB071013: optical limit