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"
18435 results found.
- Konus-Wind observations of short/hard GRB 090715A
- GRB 090715B: MASTER optical limit
- GRB 090715A: Swift-BAT refined analysis
- GRB 090715B: Swift/UVOT followup observations
- GRB 090715B: break in the optical afterglow decay
- GRB 090715B: Enhanced Swift-XRT position
- GRB 090715B: Swift XRT Refined Analysis
- GRB 090715B: Swift-BAT refined analysis
- GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
- Swift problem fixed
- GRB 090715B: Swift detection of a burst with a possible optical counterpart
- GRB 090715A: ROTSE-III Optical Limits
- GRB 090715: Swift detection of a short hard burst
- Swift satellite anomaly
- GRB 090712: Fermi GBM observation
- GRB 090712: Swift-BAT refined analysis
- GRB 090712: Swift detection of a burst
- GRB 090621B: MTM-500 optical observations
- GRB 090709A: deep optical observation with the 10.4m GTC
- GRB 090709A: Suzaku WAM observation of the prompt emission
- GRB 090709A: Swift UVOT upper limits
- GRB 090709B: Fermi GBM detection
- GRB 090709A: confirmation of the periodicity in the SPI-ACS data
- GRB 090709A: evidence for a very red afterglow at low z
- GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
- GRB 090709A: Swift XRT Refined Analysis
- GRB 090709B, Swift-BAT refined analysis
- GRB 090709A: Swift-BAT refined analysis
- GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
- GRB 090709A: Wyoming Infrared Observatory NIR upper limits
- GRB 090709A, RIMOTS optical upper limits
- GRB 090709A: Enhanced Swift-XRT position
- GRB 090709B: Swift detection of a burst
- GRB 090708 : Fermi GBM detection
- GRB 090709: Faulkes Telescope North Upper Limits
- GRB 090709: PAIRITEL NIR Upper Limits
- GRB 090709: ROTSE-III Optical Limits
- GRB 090709: Swift detection of a bright burst
- GRB 090708: Early RAPTOR Optical Limits
- GRB 090708, Swift-BAT refined analysis
- 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