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"3051 results found.
- GRB 070612A: Super-LOTIS observations
- GRB 070611: Watcher Observations
- GRB 070612B: KAIT limits
- GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
- GRB 070521: optical limit by Pi of the Sky
- GRB 070506, Swift-BAT Refined Analysis
- GRB 070506: Swift detection of a burst with optical afterglow
- GRB 070429: Swift detection of a burst
- GRB 070427: Swift detection of a burst
- GRB 070420 Swift-BAT Refined Analysis
- GRB070419A, optical observation
- GRB 070412: Optical observations at Crni Vrh
- GRB 070411: Tautenburg RRM Afterglow Confirmation
- GRB 070406: Xinglong TNT optical Upper Limit
- GRB 070318: Swift detection of a burst with an optical afterglow
- IPN localization of very bright long hard GRB 070207
- RHESSI Spectrum of GRB070125
- Konus-Wind observation of GRB 061222A
- GRB 061222b, SMARTS optical/IR afterglow observations
- GRB 061217: ROTSE-III Optical Limits
- GRB 061121: Second Epoch ATCA Radio Observations
- GRB 061126: Early Detection of the IR Afterglow
- GRB 061121: MDM Continued Monitoring
- GRB 060928: Confirmation of the X-ray afterglow detected by Swift
- GRB 061006: Swift-BAT refined analysis of the short-hard burst
- IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
- GRB 060928: Swift observations
- GRB 060923A: Keck and Gemini Observations
- GRB 060923, Swift-BAT refined analysis
- GRB 060908: Swift/UVOT Observations
- GRB 060906: observations with FRAM
- GRB 060904B: RTT150 optical observations
- GRB060814: Break in the XRT light curve
- GRB 060805B: Swift/UVOT Upper Limits
- GRB060719: prompt NIR observations with REM
- GRB050326: Host Galaxy Candidates
- GRB050124: Possible Host Galaxy
- GRB050223: Host Galaxy
- GRB 060522: PROMPT Optical Limits
- GRB 060507: Swift-BAT Refined Analysis
- GRB 060502: Swift detection of a burst with an optical counterpart
- GRB060428B, optical observation
- GRB 060428A: Refined analysis of the Swift-BAT burst
- GRB 060421: TTT Observations
- GRB060413: Swift/UVOT upper limits
- GRB 060413: Swift detection of a burst
- SGR 1900+14: BAT observations
- HETE Trigger 4043: ROTSE-III Optical Limits
- H4043, an unusual high-energy transient observed by HETE
- GRB 060322: Confirmation of Swift XRT afterglow
- GRB 060322: Swift XRT afterglow candidate
- GRB 060319: Swift detection of a burst
- Bright short hard GRB 060303: IPN localization and Konus spectrum
- GRB 060218/SN 2006aj: RBO optical observations
- GRB 060211A: Partial refined analysis on the Swift-BAT burst
- GRB 050826: Optical Afterglow and Host Galaxy
- GRB 060211: Swift detection of a long burst
- GRB 060130: PROMPT Observations
- GRB 060124: Swift-BAT detection of a burst
- GRB 060116: IR Candidate Afterglow
- GRB 060115: OT photometry with MITSuME
- Swift Trigger 172767 is not a GRB
- GRB 051105b: ART optical limits
- SGR 1806-20: continued moderate activity seen with INTEGRAL
- GRB 051022 Chandra Observations scheduled
- GRB051021b: Magellan IR Imaging
- GRB051008: optical candidate
- GRB051008: optical observation
- GRB051008: Radio Observation
- GRB 051008: Swift XRT position
- GRB 051008: Swift UVOT Candidate
- Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
- GRB 051001: Swift Detection of a Burst
- GRB050922B: Swift UVOT early upper limits.
- GRB 050922B: optical limit
- GRB050922B: Swift-BAT detection of a weak long burst
- Swift-BAT trigger 155764 is not a GRB
- Swift-BAT trigger 155764 is probably not a GRB
- GRB 050915: Swift detection of a GRB
- GRB050908: VLT R-band decay index.
- GRB 050908: Swift detection of a burst
- GRB050904: Optical Observations
- GRB 050826: Optical Candidate
- GRB050824: MASTER:OT decay
- GRB 050820: Swift detection of a GRB
- GRB050814: P60 Optical Afterglow Candidate
- Retraction of Swift Trigger 149131 (GRB 050805B)
- Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
- GRB 050802 : Lulin Optical follow-up observation
- GCN 050801: early Swift XRT analysis results
- GRB 050730: Swift XRT afterglow observations
- GRB050721A: Swift-BAT detection of a weak burst
- GRB 050626: Swift XRT observations
- GRB 050701: Swift XRT afterglow position
- Swift trigger 143708 is really GRB 050701
- GRB050603: Fading Afterglow observed by Swift UVOT
- GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
- GRB050502b: Early Observation
- GRB 050509a: Swift-BAT refined analysis
- GRB 050509A: Optical observations