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"27776 results found.
- Swift-BAT triggers 153461-153465 are not GRBs
- Retraction of Swift-BAT trigger #153355
- GRB 050824: MDM Observations
- GRB 050827: Swift XRT preliminary analysis results
- Swift Trigger #152652 is not a GRB
- GRB050827: Swift/UVOT upper limits
- GRB 050827: Optical Limit
- GRB 050827: XRT possible afterglow detection
- GRB050827: RTT150 optical observations
- GRB 050827: Swift-BAT refined analysis
- GRB050827: Swift-BAT detection of a burst
- GRB 050826: Optical Candidate
- GRB050824, HETE-2 Observation
- GRB 050826: Swift XRT preliminary analysis results
- GRB 050826: BAT refined analysis
- GRB050826: Swift/UVOT early upper limits
- GRB050824: First 2 hours of power low optical decay?
- GRB 050826: Swift XRT position
- GRB050826: Swift-BAT detection of a long burst
- GRB050824: MASTER final analysis of the OT observations
- Possible GRB050825:MASTER optical observations
- Swift-BAT trigger 152038 is definitely not a GRB
- GRB050824: CORRECTION to UVOT observing times
- Swift-BAT trigger 152038 is probably not a GRB
- GRB050824: Swift/UVOT detection of fading afterglow
- GRB050824: decay of the XRT light curve and updated X-ray spectrum
- GRB050824, I-band imaging
- GRB 050822: refined XRT analysis
- GRB 050824: XRT refined analysis and possible afterglow detection
- GRB 050824: BAT refined analysis of a soft weak burst
- GRB050824: MASTER:OT decay
- GRB050824: MASTER observation OT
- GRB050805a: MASTER optical candidat
- GRB 050824: ROTSE-III Optical Limits
- GRB050824: Swift-BAT detection of a burst
- VLT/UVES spectroscopy of GRB050820
- GRB050822: Swift/UVOT upper limits
- GRB 050820A BAT observations of second, larger episode of emission
- GRB 050822: Swift-BAT refined analysis
- GRB 050820a - corrections to GCN 3846
- Swift/UVOT UV Photometry of GRB 050820B
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB 050822: Swift detection of a long burst
- Correction to Eiso calculation in GCN 3835 on GRB 050820A
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB050820a BVRcIc field photometry
- GRB050820B XMM-Newton observation
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820B: Refined analysis of the Swift-BAT burst
- GRB050820B: BAT-Swift detection of a bright GRB
- Swift/UVOT photometry of GRB050820
- GRB050820: refined XRT analysis
- GRB 050820: Early RAPTOR detections
- GRB 050820 Swift-BAT refined analysis
- GRB050819: refined XRT analysis
- GRB 050820: Swift detection of a GRB
- GRB050820: Optical afterglow from P60
- GRB 050819 Swift-BAT refined analysis
- GRB050819: Swift XRT position
- GRB050819: Swift-BAT detection of a weak burst
- Swift-BAT trigger 150993 is not a GRB
- Swift Trigger 150823 is HETE J1900.1-2455
- GRB050817: Swift-BAT Detection of a burst
- GRB050815: Optical afterglow detection by Swift UVOT
- GRB050815: XRT refined analysis
- GRB050815: Refined analysis of the Swift-BAT burst
- GRB 050815: ROTSE-III Optical Limits
- GRB050815: Swift XRT afterglow localization
- GRB050815: Swift-BAT detection of a burst
- GRB050814: Fading red source
- GRB050814: P60 Optical Afterglow Candidate
- GRB 050814: XRT refined analysis
- GRB050814: SWIFT/UVOT observation
- GRB050814: Refined analysis of the Swift-BAT burst
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050814: Swift detection of a burst
- GRB 050813: Magellan detection of a high redshift galaxy cluster
- GRB050813, SDSS pre-burst observations
- GRB 050813: KAIT optical limit
- GRB 050813: Swift-BAT refined analysis
- GRB050813: SWIFT/UVOT observation
- GRB 050813: Swift XRT afterglow localization
- GRB 050813: Possible Short Swift-BAT GRB
- GRB050813 (Swift 150139): P60 Observations
- Swift-BAT trigger 150131 is not a GRB
- Detection of an intermediate burst from SGR 1806-20 on August 8
- GRB 050730: WSRT Radio Observations
- GRB050805b: CrAO optical limit
- GRB050805a : Null detection report
- Swift-BAT trigger 149118 is very likely not a GRB
- Retraction of Swift Trigger 149131 (GRB 050805B)
- GRB 050805b: OHP optical limits
- GRB 050805b: TAROT optical limits
- GRB050805b: MASTER optical observations
- Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
- GRB050805a: MASTER optical candidat
- Swift-BAT trigger 149118 is probably not a GRB
- GRB 050803: RTT150 optical observations
- GRB050730: Radio Detection