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"
24672 results found.
- GRB 050730: Preliminary Analysis of MIKE Spectrum
- GCN 050801: early Swift XRT analysis results
- GRB 050801: Swift-BAT refined analysis
- GRB 050730: XRT refined analysis
- GRB 050730: early TAROT optical observations
- GRB 050730, spectra and optical photometry
- GRB050730: Refined BAT analysis of the Swift-BAT burst
- GRB 050730 XMM-Newton observation
- GRB050730: Swift-BAT detection of a weak burst
- GRB050713b: Maidanak optical observations
- GRB 050724: Secure Host Redshift from Keck
- GRB 050724: WHT optical observations
- GRB050713: analysis of the XMM-Newton observation
- Swift-BAT trigger 147918 is not a real GRB
- GRB050724: VLT observations of the variable source
- GRB050709: Second Epoch Chandra Observation
- GRB050726: Swift-BAT detection of a weak burst
- GRB 050724: Optical Variability in Nearby Galaxy
- GRB 050724: J-band observations
- GRB 050724: GMOS Imaging and Spectroscopy
- GRB050724: Radio Observation
- GRB 050724: Optical imaging/astrometry
- GRB 050724: Swift/UVOT Upper Limit
- GRB050724: Refined analysis of the Swift-BAT possible short burst
- GRB 050724: possible host galaxy in DSS
- GRB 050721A: Swift-BAT refined analysis
- GRB 050721A: Early Swift XRT analysis results
- GRB050721A: optical decay
- GRB 050721: optical afterglow confirmed
- GRB 050709: Refined Spectral and Temporal Properties
- GRB050714b: Radio Observation
- GRB050712: Radio Observations
- GRB050713a: Radio Observation
- GRB 050712, Tautenburg optical afterglow observations
- Swift-BAT detection of a possible GRB
- GRB 050714B: VLT R-band observations
- GRB 050717: Additional LCO observations
- GRB 050716; J-band observations
- GRB 050717: LCO near-IR observations
- Swift/UVOT Observations of GRB 050717
- GRB 050717: Swift-BAT refined analysis
- GRB050717: Swift XRT position
- Swift detection of GRB 050717
- Swift UVOT Observations of GRB 050716
- GRB 050716: Refined XRT analysis.
- GRB050716: Refined analysis of the Swift-BAT burst
- GRB 050716: Lulin B and R band optical observations
- GRB050716, optical observation
- GRB050716: Faulkes North Telescope observation
- GRB050715: Refined analysis of the Swift-BAT burst
- GRB 050715: Swift-BAT detection
- GRB 050713b: RTT150 optical observations
- GRB050714B: Refined analysis of the Swift-BAT burst
- GRB 050714B: optical afterglow
- GRB 050714, R-band candidate
- GRB 050714, optical observations
- GRB 050713A: XRT refined analysis
- 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
- 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
- GRB050709: Candidate X-ray Afterglow from Chandra
- GRB050713: possible I-band afterglow
- 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 050709: LCO40 Observations
- GRB050709, optical observations
- 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: Swift XRT 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
- Swift trigger 143708 is really GRB 050701
- GRB 050607, radio observations
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- GRB050525a: HST Observations
- 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
- XRF050509c: Radio Detection