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"25656 results found.
- GRB 060927: Early color
- GRB 060927: Swift XRT Team refined analysis
- GRB 060927, Swift-BAT refined analysis
- GRB060927: Faulkes Telescope South observation
- GRB060927 - SDSS Pre-Burst Observations
- GRB 060927A: ROTSE-III Detection of Optical Counterpart
- GRB 060927: Swift detection of a burst
- GRB 060926: Swift-UVOT Detections
- GRB 060926: Swift XRT refined analysis
- GRB 060926, Swift-BAT refined analysis
- GRB 060926: RTT150, UVOT afterglow candidate confirmation
- GRB 060926: Swift detection of a burst
- GRB 060923C, Swift-BAT refined analysis
- GRB 060923C: VLA Observation
- GRB060923B: Swift/UVOT upper limits
- GRB 060923C: Swift XRT refined analysis
- GRB 060923C, Swift-BAT partial refined analysis
- GRB 060923A: Swift XRT refined analysis
- GRB 060923C: Keck Observations
- GRB 060923A: Keck and Gemini Observations
- GRB 060923B, Swift-BAT refined analysis
- GRB060923C : Faulkes Telescope South optical limits
- GRB060923C: Faulkes Telescope North optical observations
- GRB 060923C: optical observation
- GRB 060923C: Swift detection of a burst
- GRB 060923B: Swift detection of a burst
- GRB 060923, Swift-BAT refined analysis
- GRB 060923: Early Super-LOTIS Observations
- GRB060923: Faulkes Telescope North optical observations
- GRB 060923: KAIT observations
- GRB 060923: Swift detection of a burst
- Swift detection of IGR J17497-2821 (trigger 230504)
- Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
- GRB 060919, Swift-BAT refined analysis
- GRB060919: XRT refined analysis
- GRB 060919: TAROT optical observations
- GRB 060919: Swift detection of a burst
- GRB 060912A: VLA Observation
- GRB060825: MAGIC telescope GeV observation
- Konus-Wind observation of GRB 060912
- GRB060912: Swift/UVOT Observations
- GRB 060912: Swift XRT Team Refined Analysis
- GRB 060912, Swift-BAT refined analysis
- GRB 060912: Swift detection of a burst with an optical afterglow
- VLA observations of GRB 060908
- GRB 060908, Swift/XRT refined analysis
- GRB 060908: Swift/UVOT Observations
- GRB 060908: Danish/DFOSC optical observations
- GRB 060908, Swift-BAT refined analysis
- GRB 060908 - SDSS Pre-burst Observations
- GRB 060908: PROMPT Detection of a Bright Counterpart
- GRB 060908: Swift detection of a burst with a bright optical counterpart
- GRB 060904A: Suzaku/WAM observation of the prompt emission
- GRB060904b optical detections (delayed report due to internet outage)
- GRB 060906: optical observation
- GRB 060906: Early RAPTOR optical limits
- GRB 060906, Swift-BAT refined spectral analysis
- GRB 060906: Swift/XRT Refined Analysis
- GRB 060906: Swift-UVOT observations
- GRB 060906, Swift-BAT refined analysis
- GRB 060906: FRAM observations - flash determination (airplane)
- GRB 060906: KAIT observations
- GRB 060906 (?): P60 Optical Afterglow Candidate
- GRB 060906: Swift detection of a probable burst
- GRB 060904B: RTT150 optical observations
- GRB060904A: Swift/UVOT optical observations
- GRB 060904A: pseudo-z from spectral parameters of the prompt emission
- GRB 060904B: Swift-BAT refined analysis
- GRB060904b: Optical observations with Swift/UVOT
- Konus-Wind observation of GRB 060904A
- GRB 060904B: Swift-XRT refined analysis
- GRB 060904A: Refined analysis of the Swift-BAT burst
- GRB 060904A: Swift-XRT refined analysis
- GRB 060904B: Optical observations at Crni Vrh
- GRB 060904B: TAROT optical counterpart observations
- GRB060904B - SDSS Pre-Burst Observations
- GRB 060904: TAROT optical observations
- GRB 060904B: Swift detection of a burst with optical counterpart
- GRB 060904B: ROTSE-III Detection of Optical Counterpart
- GRB060904 - SDSS Pre-Burst Observations
- GRB 060904: Swift detection of a bright burst
- GRB 060901: Swift/XRT Refined Analysis
- GRB 060604: VLA Observation
- GRB 060814: Suzaku/WAM observation of the prompt emission
- GRB 060605: VLA Observation
- GRB 060707: VLA observation
- GRB 060825: VLA observations
- GRB 060825: pseudo-z from spectral parameters of the prompt emission
- Swift-BAT trigger 226614 is not a GRB
- GRB060826 - SDSS Pre-Burst Observations
- GRB 060826(?): Swift detection of a possible burst
- GRB 060825: XRT Team Refined Analysis
- GRB 060825: Swift-BAT Refined Analysis
- GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
- GRB060825: Liverpool Telescope optical observations
- GRB 060825: TAROT optical observations
- GRB 060825: Swift detection of a burst
- GRB 060814: pseudo-z from spectral parameters of the prompt
- GRB060814: Break in the XRT light curve
- GRB060813: Break in the XRT light curve