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.
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"24382 results found.
- Konus-Wind and Konus-A observation of GRB 070508
- GRB 070510: Swift detection of a possible burst
- RHESSI Spectrum of GRB070508
- GRB 070509, Swift-BAT refined analysis
- GRB 070508: Suzaku/WAM observation of the prompt emission
- GRB 070509: ROTSE-III Optical Limits
- GRB070508: Swift/UVOT Observations
- GRB 070508, SMARTS optical afterglow observation
- GRB 070508, Swift-BAT refined analysis
- GRB 070508: Multicolor optical observations and possible redshift limit
- GRB070412: MAGIC telescope GeV observation
- GRB 070506, Swift-BAT Refined Analysis
- GRB070429B: VLT observations
- GRB 070309: Swift-XRT afterglow confirmation
- Swift/UVOT observations of GRB070429B
- GRB 070429B, Swift-BAT refined analysis
- Swift/UVOT observations of GRB070429A
- GRB 070429A, Swift-BAT refined analysis
- GRB 070429B: ROTSE-III Optical Limits
- GRB 070429: ROTSE-III Optical Limits
- GRB 070427, Swift-BAT Refined Analysis
- GRB 070411: Late-time Keck imaging
- GRB070419B: Suzaku WAM observation of the prompt emission
- GRB 070420, SMARTS optical/IR afterglow observations
- GRB 070411, deep LBT photometry
- GRB 070411: break in the optical light curve
- GRB 070420 Swift-BAT Refined Analysis
- GRB070419A: Kuiper Optical detection
- GRB 070419A: MARGE Observations
- GRB 070420: Faulkes Telescope South Observations
- GBR 070419A: Swift/XRT refined analysis
- GRB 070420: NIR and optical afterglow confirmed
- GRB 070419A: MITSuME Okayama Observations
- GRB 070419B, Swift-BAT refined analysis
- GRB 070419A Swift-BAT Refined Analysis
- GRB 070419A: RAPTOR Detection of Early Emission
- GRB 070419A: Faulkes Telescope North Optical Observations
- GRB070419A, optical observation
- GRB 070419: P60 Confirmation of Optical Afterglow
- GRB 070419A: ROTSE-III Optical Limits
- GRB 070418: Optical and IR observations with KANATA
- Trigger 276045: Swift detection of a possible burst
- IBAS Alert n.4202: not a real GRB
- GRB 070318, SMARTS optical/IR afterglow observations
- GRB070412: Swift UVOT observations
- IBAS Alert n.4199: Not a GRB
- GRB 070412, Swift-BAT refined analysis
- GRB 070412 Liverpool Telescope optical limit
- GRB 070411: Optical photometry at Crni Vrh
- GRB 070411, Swift-BAT refined analysis
- GRB 070412: Swift detection of a burst
- GRB 070411 : Liverpool Telescope Observations
- GRB 070411: ROTSE-III Detection of Optical Counterpart
- GRB 070406, Swift-BAT refined analysis
- GRB 070406: Correction to the optical candidate in GCN6253
- GRB 070406: Gemini South Imaging and XRT analysis
- GRB 070406: NOT observations
- GRB 070406: The exprosure time of Xinglong TNT optical Upper Limit
- GRB 070402: Suzaku WAM observation of the prompt emission
- GRB 070328: Suzaku WAM observation of the prompt emission
- INTEGRAL ToO Observation of SGR1806-20
- UVOT observations of GRB070330
- GRB 070330, Swift-BAT refined analysis
- GRB 070330, SMARTS optical/IR observations
- GRB 070330 - Watcher Observations
- GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
- Konus-Wind observation of GRB 070328
- long burst from SGR 1806-20 detected on March 26
- GRB 070328, Swift-BAT refined analysis
- GRB070220: optical observations
- GRB070208: optical observations
- GRB070318: Swift UVOT indicates unusual optical/UV afterglow
- Short-Hard GRB 070209: PROMPT Observations
- GRB 070318: absorption-line redshift
- GRB070318: Swift UVOT continuing observations
- GRB 070318, Swift-BAT refined analysis
- IBAS Alert n. 4176: not a GRB
- GRB 070311: Tautenburg sees afterglow fading
- IBAS Alert n. 4169: not a GRB
- GRB 070311: Optical observation.
- GRB 070309: variability of the XRT afterglow candidate
- GRB 070311: RAPTOR Detection of Optical Emission
- GRB 070311: MDM Optical Detection
- GRB 070311: MITSuME Okayama Optical Observation
- GRB 070311: Swift-XRT refined analysis
- GRB 070311: REM candidate afterglow
- GRB 070311: a long GRB detected by INTEGRAL
- GRB060901: Candidate optical afterglow
- GRB 070309: A long GRB detected by INTEGRAL
- GRB 070125: X-ray light curve analysis
- IBAS Alert 4162: Not a GRB
- GRB 070306: NOT observations
- GRB 070306, Swift-BAT refined analysis
- GRB 070306: XRT Team Refined Analysis
- GRB 070306: Optical and IR observations with KANATA
- GRB070227: Swift-XRT refined analysis
- GRB 070125, deep late-time optical observation
- GRB 070223: Optical Observations
- GRB 070227, Swift-BAT refined analysis
- GRB 920925C: optical afterglow candidate