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"20537 results found.
- GRB 050730: RTT150 optical observations
- GRB 050730: Swift XRT afterglow observations
- GRB 050730: PROMPT VRcIc Observations
- GRB050730, afterglow observations
- GRB050730: confirmation of redshift
- GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
- GRB 050730, SMARTS optical/IR afterglow observations
- GRB050730: Liverpool Telescope optical observations
- GRB050730: Swift-BAT detection of a weak burst
- GRB 050709: PROMPT Rc Observations
- GRB050713b: Maidanak optical observations
- GRB 050724: Secure Host Redshift from Keck
- GRB 050724: WHT optical observations
- GRB050726: Swift UVOT observations
- GRB 050724: Chandra Observations of the X-ray Afterglow
- GRB050724: Refined Radio Position
- GRB 050724, SMARTS optical/IR afterglow observations
- GRB 050726, SMARTS optical/IR observations
- GRB 050727: RTT150 optical observations
- GRB050724: VLT observations of the variable source
- GRB 050726: PROMPT Rc Observations
- GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
- GRB050724: Further Radio Observations
- GRB 050726: early Swift XRT analysis results
- 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: spectroscopy of object in the XRT error circle
- GRB 050724: optical and near-IR observations
- GRB 050724: Optical imaging/astrometry
- GRB 050724: RTT150 optical observations
- GRB 050724 : Lulin early R-band monitoring observations
- GRB 050724: possible host galaxy in DSS
- GRB 050721: early afterglow light curve
- GRB 050721: optical afterglow confirmed
- GRB 050721a: Optical Observations
- GRB 050717: PROMPT RcIc Observations
- GRB050712: Radio Observations
- 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: Refined XRT analysis.
- Swift detection of GRB 050717
- GRB 050716 - UKIRT identification of candidate afterglow
- Swift UVOT Observations of GRB 050716
- GRB 050716: Refined XRT analysis.
- GRB 050716: Lulin B and R band optical observations
- GRB 050716: Optical Observations
- GRB050716: Faulkes North Telescope observation
- Swift/BAT detection of GRB 050716
- Swift UVOT Observations of GRB 050714B
- GRB 050714B: refined XRT analysis
- GRB 050713b: RTT150 optical observations
- Swift detection of a long transient (GRB 050714B?)
- GRB 050709: optical afterglow candidate
- GRB 050714, optical observations
- GRB 050709: Spectroscopy
- GRB050713B :Swift/UVOT observations
- GRB050712: TNG R-band observations
- GRB050712: Swift UVOT Observation of Afterglow Emission
- GRB 050713A : Lulin R-band observation
- GRB 050713b : Lulin R-band observations
- GRB050713B: Faulkes North Telescope observation
- RBO RI observations of GRB 050713A
- GRB 050713B
- GRB050713: Liverpool Telescope prompt observations
- GRB 050712, optical observations
- GRB050709: Candidate X-ray Afterglow from Chandra
- GRB 050713, R-band observations at NOT
- GRB 050713: ARC NIR Detections and Identification of Fading
- GRB 050713: Swift detection of Bright Burst
- GRB050709: Radio Observations
- GRB 050709: Swift UVOT and XRT observations
- GRB 050712: Swift detection of a weak burst
- GRB 050709: LCO40 Observations
- GRB050709, optical observations
- PROMPT Rc Observations of GRB 050709
- 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, optical observations
- GRB 050408: ARC 3.5-meter NIR Observations
- Swift UVOT observations of GRB 050701
- GRB 050607, radio observations
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- GRB 050525A: Swift Late-Time Decay Rate
- GRB050525a: HST Observations
- CORRECTION: GRB050603 Swift UVOT Afterglow Observations
- H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
- XRF 050509c: Optical monitoring
- XRF050509c: Radio Detection
- GRB 050416(a): Host Galaxy Redshift Determination
- GRB 050607: MDM Observation