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"
- Swift/BAT detection of GRB 050716
- GRB050715: Refined analysis of the Swift-BAT burst
- GRB 050715: Swift-BAT detection
- Swift UVOT Observations of GRB 050714B
- Konus-Wind observation of GRB 050713A
- GRB 050714B: refined XRT analysis
- GRB 050713b: RTT150 optical observations
- GRB 050714B: candidate afterglow does not fade
- GRB050714B: Refined analysis of the Swift-BAT burst
- GRB 050714B: optical afterglow
- Swift detection of a long transient (GRB 050714B?)
- GRB 050709: optical afterglow candidate
- GRB 050714, R-band candidate
- GRB 050714: Swift XRT afterglow position
- GRB 050714, optical observations
- GRB 050714A: ROTSE-III Optical Limits
- GRB 050714 - A long GRB detected with INTEGRAL
- GRB 050713A: XRT refined analysis
- GRB 050709: Spectroscopy
- GRB 050713A: RAPTOR detection of early optical emission
- GRB050713B :Swift/UVOT observations
- GRB050713b: XRT refined analysis
- GRB050712: TNG R-band observations
- GRB 050713B: Swift-BAT Refined Analysis
- Swift-BAT Trigger 145729 is not a GRB
- GRB 050713A: Swift/UVOT observation
- GRB 050713A : Swift-BAT Refined Analysis
- GRB050712: Swift UVOT Observation of Afterglow Emission
- GRB 050713A : Lulin R-band observation
- GRB 050713A XMM-Newton observation
- GRB 050713b : Lulin R-band observations
- GRB050713B: Faulkes North Telescope observation
- RBO RI observations of GRB 050713A
- GRB 050713B
- GRB050709 : Chandra source optical counterpart
- GRB050713: Liverpool Telescope prompt observations
- GRB 050712, optical observations
- GRB 050713 : Planned XMM-Newton observation
- GRB050709: Candidate X-ray Afterglow from Chandra
- GRB 050713, R-band observations at NOT
- GRB 050713: ARC NIR Detections and Identification of Fading
- GRB050713: possible I-band afterglow
- GRB 050713: Swift detection of Bright Burst
- GRB 050713A: ROTSE-III Optical Limits
- GRB050712: XRT refined analysis
- GRB050709: Radio Observations
- GRB 050709: Swift UVOT and XRT observations
- GRB 050712: Swift-BAT Refined Analysis
- GRB050712: UVOT candidate optical counterpart
- GRB 050712: Swift XRT afterglow position
- GRB 050712: Swift detection of a weak burst
- GRB 050709: LCO40 Observations
- GRB050709, optical observations
- GRB050709: A Possible Short-Hard GRB Localized by HETE
- PROMPT Rc Observations of GRB 050709
- GRB 050525a: PROMPT VRcIc Detections
- GRB 050525a: ARC 3.5-meter Optical and NIR Observations
- GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
- GRB 050626 optical observations
- GRB 050626: Swift XRT observations
- GRB 050701
- GRB 050701, optical observations
- GRB 050408: ARC 3.5-meter NIR Observations
- GRB 050701: Refined XRT analysis
- Swift UVOT observations of GRB 050701
- GRB050701: Swift-BAT Refined analysis
- GRB 050701: Swift XRT afterglow position
- Swift trigger 143708 is really GRB 050701
- GRB 050607, radio observations
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- GRB 050626 - Correction to GCN 3552
- GRB 050626 - a long GRB detected with INTEGRAL
- GRB 050525A: Swift Late-Time Decay Rate
- GRB050525a: HST Observations
- CORRECTION: GRB050603 Swift UVOT Afterglow Observations
- H3804: A Possible New XRB Detected by HETE
- H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
- XRF 050509c: Optical monitoring
- Konus-Wind observation of an intermediate burst from SGR 1806-20
- IBAS Alert #2512 is NOT a GRB
- XRF050509c: Radio Detection
- GRB 050416(a): Host Galaxy Redshift Determination
- GRB 050607: MDM Observation
- GRB 050607 optical decay
- GRB 050607: RTT150 optical observations
- GRB050607: refined analysis of prompt REM observations
- Swift/UVOT observations of GRB050607
- GRB 050607 : Lulin R-band observation
- GRB 050607: PROMPT VRcIc Observations
- GRB 050607: RAPTOR-S Early Optical Limits
- GRB050607: KAIT optical limits
- GRB 050525a, Mid-Infrared Observations
- GRB 050607: Optical decay and spectral slope
- GRB 050607: MDM Observations
- GRB050607,optical observation
- GRB 050607 - XRT refined data analysis
- Optical Afterglow of GRB 050607
- GRB050607 optical limit by "Pi of the Sky"
- GRB050607: Swift Detection of a long GRB
- GRB050607: P60 Observations