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"16167 results found.
- Swift UVOT observations of GRB 081203A
- GRB 081130B: MASTER prompt optical observations
- GRB081203: optical observation
- GRB 081203: Swift detection of a burst with a bright optical counterpart
- GRB 081128: optical observation
- GRB 081130: MASTER VWF prompt optical observations Fermi GRB
- GRB 081128A: optical observations
- GRB 081128: Liverpool Telescope afterglow confirmation
- GRB081128: optical observations
- GRB081128 : Lulin optical follow-ups
- GRB 081128: Optical observation of xinglong TNT
- GRB 081126: GRT Optical Observation
- GRB 081126: Confirmation of the Optical Afterglow
- GRB 081126: optical observations
- GRB 081126: TAROT Calern observatory optical observations
- GRB 081121, SMARTS optical/IR afterglow observations
- GRB081121: Fermi GBM detection
- GRB081121: Refined Swift/UVOT observations
- GRB 081121: Swift-XRT refined analysis
- GRB 081121: Magellan Redshift
- GRB 081121: GROND observations
- GRB081121: Swift/UVOT observations
- GRB 081121: Swift detection of a burst
- GRB 081121: ROTSE-III Detection of Optical Counterpart
- GRB081118 : optical upper limit
- GRB 081016b, SMARTS optical/IR observations
- VLA Radio upper limit on GRB 081118
- GRB 081118: VLT redshift
- GRB 081118: optical afterglow candidate
- GRB 081109A: confirmation of possible detection host galaxy
- GRB 081102: RTT150 Optical observations
- GRB 081110: MASTER: first optical observations Fermi GRB
- GRB 081109: TAROT La Silla observatory optical observations
- GRB 081102: MASTER refind and final results
- GRB 081109B: Swift/UVOT refined analysis
- GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 081109A: Possible Swift-UVOT detection
- GRB 081109: Swift/UVOT upper limits
- GRB 081109A optical upper limit
- Swift-BAT Trigger 334129: possible burst
- GRB 081109: REM NIR afterglow detection
- GRB 081028 - PAIRITEL NIR detection
- GRB 081104: GROND found no Optical/NIR Afterglow
- UVOT/Swift observations of GRB081105
- GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
- GRB081104: Swift/UVOT Upper Limits
- GRB 081104 : Faulkes Telescope South observations
- GRB 081102: MASTER prompt optical limit
- GRB 081102: Swift/UVOT refined analysis
- GRB 081102: OPTIMA-Burst optical upper limit
- SGR 0501+4516: optical observations in August
- GRB 081024B: BTA deep optical observations
- GRB 081028: CrAO optical observations
- GRB 081024B: new Swift-XRT observations
- GRB 081029, SMARTS optical/IR afterglow observations
- GRB 081029: UVOT Detection of the Optical Afterglow
- GRB 081029: Redshift Confirmation from Gemini-South
- GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
- GRB 081029: REM observations
- GRB 081029: GROND Detection of the Optical/NIR Afterglow
- GRB 081029: ROTSE-III Detection of Optical Counterpart
- GRB 081028: Magellan redshift
- GRB081028: UVOT detection of a brightening afterglow
- Swift UVOT observations of GRB081028
- GRB 081028: TAROT Calern observatory optical observations
- GRB 081028: optical observations at the NOT
- GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
- Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
- Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
- GRB081025: RTT150 optical observations
- Swift UVOT observations of GRB081025
- Swift UVOT observations of GRB081024B
- Swift UVOT observations of GRB 081024
- GRB 081024: Faulkes Telescope North optical observations
- GRB 081024: KAIT Optical Limits
- GRB 081024A: ROTSE-III Optical Limits
- GRB 081016B: Swift/UVOT Upper Limits
- GRB 081016B: ROTSE-III Optical Limits
- Swift-BAT triggered on the flare star Algol
- GRB 080430: optical observations
- GRB 081008 optical upper limit
- GRB 081012: Swift/UVOT analysis of initial observations
- GRB 081012: ROTSE-III Optical Limits
- GRB081011: UVOT detection of an optical afterglow
- GRB 081008, SMARTS optical/IR afterglow observations
- GRB 081007: Radio Detection
- GRB 081008: VLT redshift confirmation
- GRB 081008: Gemini-South Absorption Redshiftt
- GRB 081008: Swift detection of a burst with optical afterglow
- GRB 081008: ROTSE-III Detection of Optical Counterpart
- GRB 081007, SMARTS optical afterglow observations
- GRB 081007: Early RAPTOR measurements of optical counterpart
- GRB 081007: Gemini-south redshift
- GRB 081007, Faulkes Telescope North optical observations
- GRB 081007, SMARTS optical/IR afterglow observations
- GRB 081007: REM NIR and optical counterpart
- GRB 081007: Swift detection of a burst with optical afterglow
- GRB 081003B: TAROT Calern observatory optical observations
- GRB 081003A: OSN optical observations
- GRB081003B: Optical limits from Spain