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"19592 results found.
- GRB 090708: ROTSE-III Optical Limits
- GRB 090708: Swift detection of a burst
- Swift-BAT trigger 356516 is not a GRB
- Possible GRB090705: Swift-XRT observations
- GRB 090705: PAIRITEL NIR Observations
- GRB 090705: Swift detection of a possible burst
- XRF 090702 : RTT150 optical observations
- GRB 090618: Mondy optical observations
- GRB 090529: CrAO optical upper limit
- GRB 090529: MTM-500 optical observations
- GRB 090529: Mt.Terskol optical observations
- XRF 090702: Swift-XRT refined analysis
- GRB 090702: UVOT upper limits
- XRF 090702: Swift-XRT afterglow position
- GRB 090628: Swift XRT refined analysis
- GRB 090618: RTT150 optical observations
- GRB 090628: Swift/UVOT Upper Limits
- GRB 090628: Swift-BAT refined analysis
- GRB 090628: GROND upper limits
- GRB 090628: Enhanced Swift-XRT position
- GRB 090626: IPN localization
- GRB 090628: Swift/UVOT Finding Chart Observation
- GRB 090628: Swift XRT position
- GRB 090628: Swift detection of a burst
- GRB 090625B: Swift/UVOT Upper Limits
- GRB 090625B: Swift-XRT refined analysis
- GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
- GRB 090621A: Enhanced Swift-XRT position
- GRB 090621B: GRT Optical Observation
- GRB 090621A: GRT Optical Observation
- PAIRITEL observations of GRB 090618
- GRB 090621B: Fermi GBM detection
- GRB 090621B: I-band observations from 1.23m CAHA
- GRB 090621: Fermi GBM observation
- GRB 090621B: Swift/UVOT Upper Limits
- GRB 090621B: Swift-BAT refined analysis
- GRB 090621B: Swift-XRT refined analysis
- GRB 090621B: RTT150 optical observations
- GRB 090618: RTT150 optical observations
- GRB 090621A: Swift-BAT refined analysis
- GRB 090621B: Swift detection of a short hard burst
- GRB 090621: Swift/UVOT Upper Limits
- GRB 090621: Swift-XRT Team refined analysis
- GRB 090621: Swift detection of a burst
- GRB 090618: ZTSh optical observations
- GRB090618, underlying supernova search
- GRB 090618: Fermi GBM observation
- GRB 090618, Swift-BAT refined spectral analysis
- GRB090618 - Continued optical monitoring and light curve break
- GRB 090618: Swift-BAT refined analysis
- GRB090618: Swift-XRT team refined analysis
- GRB090618: Swift/UVOT bright afterglow detection
- Swift XRT observations of GRB 090531A
- GRB 090618: AGILE observations
- GRB 090618: Enhanced Swift-XRT position
- GRB 090618 Faulkes Telescope North observations
- GRB 090618: ROTSE-III Detection of Optical Counterpart
- GRB090618: P60 Optical Afterglow
- GRB 090618: Swift detection of a bright burst with optical afterglow
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- RXTE Discovery of Pulsations from SGR 0418+5729
- GRB 090531B: Fermi GBM detection
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- GRB 090607: XRT Team Refined Analysis
- GRB 090607: Swift/UVOT Upper Limits
- GRB 090607: Swift-BAT refined analysis of the SHB
- GRB 090607: Faulkes Telescope North observations
- GRB 090607: Swift detection of a burst
- Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
- GRB 090530: RTT150 Optical Observation
- GRB 090529A: RTT150 Optical Observations
- GRB 090531B: GROND observation
- GRB 090530: Early RAPTOR Optical Observations
- GRB 090531B: Swift/BAT spectral lag results
- Corrections to GRB 090531B Swift/UVOT Upper Limits
- GRB 090531B, RIMOTS optical upper limits
- GRB 090531B: Swift/UVOT Upper Limits
- GRB 090530: GRT Optical Observation
- GRB 090531B: Swift-BAT refined analysis
- Initial Swift/UVOT observations of GRB 090531B
- GRB 090531B: Swift-XRT candidate afterglow position
- GRB 090531B: ROTSE-III Optical Limits
- GRB 090531B: Swift detection of a burst
- GRB 090531: Swift-BAT refined analysis
- GRB 090530: break in light curve
- GRB 090531: GROND upper limits
- GRB 090531: Swift detection of a burst
- GRB090530: Swift XRT refined analysis
- GRB090530: Swift/UVOT afterglow detection
- GRB 090529: Swift-XRT refined analysis
- GRB 090530: Enhanced Swift-XRT position
- GRB 090530: Swift-BAT refined analysis
- GRB 090530: PAIRITEL NIR Detections
- GRB 090530A: ROTSE-III Detection of Optical Counterpart
- GRB 090530: Swift detection of a burst with an optical counterpart
- GRB 090529: optical observations
- GRB 090529: TLS Afterglow Observations
- GRB090529: UVOT/Swift detection of a brightening optical afterglow
- GRB 090529: Swift-BAT refined analysis
- GRB 090529: Enhanced Swift-XRT position