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"
2722 results found.
- GRB 080129: GROND detection in all bands, and fading
- GRB 080129: GROND detection of the optical/NIR afterglow, and fading
- IPN triangulation of GRB080122
- GRB 080121: Nearby SDSS galaxies
- GRB 080120: Swift-XRT refined analysis
- GRB080120: Swift XRT position
- GRB 071227: Swift detection of a burst
- GRB071020: optical observations
- GRB 071122 Swift-XRT refined analysis
- GRB 071122: Corrected P60 Coordinates
- GRB 071122: P60 Optical Afterglow Candidate
- GRB 071122: Swift detection of a burst
- GRB 071118, Swift-BAT refined analysis
- VLT FORS2 observations of short hard GRB071112B
- ATCA radio observations of short hard burst GRB 071112B
- GRB 071112C: SARA upper limit
- GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
- GRB 071028B Swift-BAT detection of a burst
- GRB 071025: Kuiper Telescope Optical Observations
- GRB 071025, Swift-BAT refined analysis
- GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
- GRB 071013: TNT optical data refined analysis
- GRB 071010B: Photometry after 1.6 days
- GRB 071010A: Continued Keck Imaging
- GRB 071006, Swift-BAT refined analysis
- GRB 071010B: Swift detection of a burst
- Recent SGR1806-20 Activity
- GRB 070917: Swift detection of a bright burst
- GRB 070808, Swift-BAT refined analysis
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- GRB 070729, Swift-BAT refined analysis
- GRB 070724B: Swift-XRT afterglow likely candidate
- GRB 070721A : Faulkes Telescope South optical limit
- GRB 070721A, Swift-BAT refined analysis
- GRB 070621: Watcher Observations
- GRB070520B: optical observations
- GRB 070521, optical observation
- GRB 070521, Swift-BAT refined analysis
- GRB 070521: optical limit by Pi of the Sky
- GRB 070419A: RAPTOR Detection of Early Emission
- GRB070330: Correction to UVOT position
- UVOT observations of GRB070330
- GRB 070330, Swift-BAT refined analysis
- GRB 070330: Swift-XRT refined analysis
- GRB 070330: Swift detection of a burst
- GRB 070311: MDM Optical Detection
- GRB070227: Swift-XRT refined analysis
- VLA observation of GRB 070224
- GRB 070227: optical observations
- GRB 070227: optical observations
- GRB 070209: Swift XRT analysis
- GRB 070103: Swift detection of a burst
- Retractions of previous Swift-BAT triggers
- GRB 061201: Magellan Redshift of nearby Abell cluster
- GRB061202 optical limit by "Pi of the Sky"
- RHESSI Spectrum of GRB061126
- GRB 061126: SARA Observations
- GRB 061126: Swift detection of a burst
- GRB061122: Swift/UVOT Optical Observations
- GRB 061110: Swift detection of a burst
- GRB061019: second epoch CrAO observations
- GRB 061028: MDM Observations
- GRB 061028, Swift-BAT refined analysis
- GRB061019: optical observations
- GRB 061007: Second Epoch ATCA Radio Observations
- GRB 061007: ATCA Radio Observations
- GRB060912: Swift/UVOT Observations
- GRB060904b optical detections (delayed report due to internet outage)
- GRB 060904B: RTT150 optical observations
- Two bright bursts from SGR 1806-20 detected with IBAS
- GRB 060825: VLA observations
- GRB 060825: XRT Team Refined Analysis
- GRB 060825: Swift-BAT Refined Analysis
- GRB060825: BOOTES-IR optical observations
- Konus-Wind observation of GRB 060813
- Swift detection of an outburst from the 4U 1246-58 LMXB burster
- GRB 060805: Swift detection of a burst
- GRB 060801, optical observation
- GRB 060605: SkyNet Optical Limits
- GRB 060712: Swift detection of a burst
- GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
- GRB 060607: REM NIR afterglow
- GRB 060522: Swift detection of a burst with possible optical afterglow
- GRB 060516: Swift detection of a burst
- GRB060501: P60 imaging and afterglow candidate
- GRB060428B, optical observation
- GRB060424: optical afterglow detection
- GRB 060424: Refined analysis of the Swift-BAT burst
- GRB 060403: Swift detection of a burst
- GRB 060312: ROTSE-III Optical Limits
- Bright short hard GRB 060303: IPN localization and Konus spectrum
- GRB 060223B: Swift XRT possible afterglow
- GRB 060218/SN 2006aj: RBO optical observations
- GRB 060223B: ART optical limits
- GRB 060206: Swift/UVOT Observations
- GRB 060209(?): Swift-BAT detection of a possible burst
- GRB060206: Swift-BAT detection of a burst
- GRB060124: detailed XRT analysis
- GRB 060123: Swift detection of a very long, faint burst
- GRB 060117: PROMPT Observations