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"19530 results found.
- GRB 070427: Swift detection of a burst
- GRB070419B: Suzaku WAM observation of the prompt emission
- GRB 070411, deep LBT photometry
- GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
- GRB 070420 Swift-BAT Refined Analysis
- GRB070419A: Kuiper Optical detection
- GRB070419a: Swift UVOT observations
- GRB 070419A: MARGE Observations
- GRB 070420: optical rebrightening observed at Mt. John
- GRB 070420: Swift XRT refined analysis
- GRB070420: Swift UVOT continuing observations
- GRB 070420: Faulkes Telescope South Observations
- GBR 070419A: Swift/XRT refined analysis
- GRB 070420: TAROT La Silla observatory optical observations
- GRB 070420: NIR and optical afterglow confirmed
- GRB 070420: Swift detection of a burst with optical afterglow
- GRB 070419A: Early Super-LOTIS Observations
- GRB 070419B, Swift-BAT refined analysis
- GRB 070419A Swift-BAT Refined Analysis
- GRB 070419A: RAPTOR Detection of Early Emission
- GRB 070419B: Swift XRT refined analysis
- GRB 070419A, Optical observations
- GRB070419 - SDSS Pre-Burst Observations
- GRB 070419A: Faulkes Telescope North Optical Observations
- GRB 070419B optical afterglow candidate
- GRB 070419B: optical afterglow candidate
- GRB070419A, optical observation
- GRB070330: Correction to UVOT position
- GRB 070419B: Swift detection of a burst
- GRB 070419A: ROTSE-III Optical Limits
- GRB 070419: Swift detection of a burst
- Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
- Trigger 276045: Swift detection of a possible burst
- GRB 070406: Swift XRT refined analysis
- GRB 070411: TLS data shows plateau, flares
- GRB070412: Swift UVOT observations
- GRB 070411: Swift/UVOT observations
- GRB 070412, Swift-BAT refined analysis
- GRB 070412: Swift-XRT refined analysis
- GRB 070411: Swift-XRT refined analysis
- GRB 070412: Optical observations at Crni Vrh
- GRB 070412: Swift-XRT refined position
- GRB 070411, Swift-BAT refined analysis
- GRB 070412: Swift detection of a burst
- GRB 070411: ROTSE-III Detection of Optical Counterpart
- GRB 070411: Tautenburg RRM Afterglow Confirmation
- GRB 070411: Swift detection of a burst with optical afterglow
- GRB 070406: Swift XRT team further analysis
- GRB 070406: Astrometrically Refined XRT Position, Unfading Source
- GRB 070406, Swift-BAT refined analysis
- GRB070406: Swift UVOT observations
- GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
- GRB 070406: SARA upper limit
- GRB 070406: Xinglong TNT optical Upper Limit
- GRB 070406: Swift detection of a burst
- INTEGRAL ToO Observation of SGR1806-20
- UVOT observations of GRB070330
- GRB 070330, Swift-BAT refined analysis
- GRB 070330: TAROT La Silla observatory optical observations
- GRB 070330: Swift-XRT refined analysis
- GRB 070330: Swift detection of a burst
- GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
- Konus-Wind observation of GRB 070328
- GRB 070328: Swift/UVOT Upper Limits
- GRB 070328: Swift/XRT Refined Analysis
- GRB 070328, Swift-BAT refined analysis
- GRB 070328: Swift detection of a burst
- GRB070318: Swift UVOT indicates unusual optical/UV afterglow
- GRB 070318: Gemini + Magellan spectra
- GRB070318: Swift UVOT continuing observations
- GRB070318: Swift-XRT refined analysis
- GRB 070318: Swift/UVOT Continued Observations
- GRB 070318, Swift-BAT refined analysis
- GRB 070318: Swift detection of a burst with an optical afterglow
- GRB 070311: Late Central Engine Activity Optical Flare??
- VLA observation of GRB 070311
- GRB 070309: variability of the XRT afterglow candidate
- GRB 070311: Swift/UVOT Upper Limits
- GRB 070311: Swift-XRT refined analysis
- GRB070309: Swift/XRT possible afterglow detection
- GRB 070125: Chandra X-ray Confirmation of Jet Break
- GRB 070309: Swift/UVOT Upper Limits
- Swift UVOT Finding Charts for GRB 070309
- GRB 070125: X-ray light curve analysis
- VLA observation of GRB 070306
- GRB 070306: NOT observations
- GRB 070306 Swift/UVOT refined analysis
- GRB 070306, Swift-BAT refined analysis
- GRB 070306: XRT Team Refined Analysis
- GRB070306 - SDSS Pre-burst Observations
- GRB 070306: Swift detection of a burst
- GRB070227: Swift-XRT refined analysis
- GRB 070125, deep late-time optical observation
- VLA observation of GRB 070224
- GRB 070227: optical observations
- GRB 070223: Optical Observations
- GRB 070227: optical observations
- GRB 070227: Swift/UVOT Upper Limits
- GRB 070227: TAROT La Silla observatory optical observations
- GRB 070227, Swift-BAT refined analysis