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"3344 results found.
- GRB051109A: XRT refined analysis
- GRB 051109a: IR Photometry and Astrometry
- GRB 051109a: IR Detections
- GRB051028: Swift-XRT refined analysis
- XRT observations of GRB 051105A
- GRB 051022: XRT Refined Spectral and Temporal Analysis
- Chandra Observations of GRB 051022
- GRB051012: Swift-XRT analysis
- GRB 051022 Chandra Observations scheduled
- GRB 051022: SOAR JKs Observations
- GRB 051022, J & K-band observation
- GRB 051021: P200 Ks Observations
- GRB051021: Swift XRT analysis
- GRB 051016b: Gemini Near IR Observations
- GRB051008: Swift XRT refined analysis
- GRB 051001: AAT infra-red observations
- GRB 051001: ROTSE-III Optical Limits
- GRB050925: Swift/XRT limits
- GRB/SGR 050925: IR Observations
- GRB050922B: refined XRT analysis
- GRB050820B: analysis of the XMM-Newton observation
- Swift-BAT trigger 155764 is not a GRB
- GRB050916 : Swift-XRT refined analysis
- GRB050911: Upper limit on X-ray afterglow
- Swift-BAT trigger 155072 ground analysis
- GRB 050906: Swift XRT upper limit
- GRB 050904: early Swift XRT analysis results
- GRB 050827: Swift XRT preliminary analysis results
- GRB 050827: P200 NIR Observations
- GRB050824: decay of the XRT light curve and updated X-ray spectrum
- GRB 050730: XRT refined analysis
- GRB 050724: Chandra Observations of the X-ray Afterglow
- GRB050713: analysis of the XMM-Newton observation
- GRB 050714a: Refined XRT analysis and afterglow confirmation
- GRB 050713: ARC NIR Detections and Identification of Fading
- GRB 050525a: ARC 3.5-meter Optical and NIR Observations
- GRB 050626: Swift XRT observations
- GRB 050408: ARC 3.5-meter NIR Observations
- GRB 050603 - XRT data analysis of the first day
- GRB 050525a, infrared observations
- GRB 050509b: refined XRT/Chandra afterglow position analysis
- XRF050522: NIR observations of XRT candidate
- XRF 050522: Continued NIR P200 Monitoring
- XRF050522: Near-infrared Observations
- XRF050509C: Chandra Afterglow Detection
- XRF 050509c: Swift XRT Upper Limit
- GRB 050520: P200 Observations
- GRB 050504: Swift XRT afterglow candidate has faded
- Refined Chandra analysis of GRB 050509b
- Chandra observation of GRB 050509b
- GRB 050502a: Swift XRT Upper Limit
- GRB (?) 050504: IR Observations, Intriguing Source
- GRB 050502: Confirmed variability of the afterglow candidate +
- GRB 050421: Further Analysis of IR imaging
- GRB 050421: IR Observations
- GRB050326: analysis of the XMM-Newton observation
- GRB050416B: IR observations
- GRB050416: P200 NIR Observations
- GRB 050408: Swift XRT measurement of possible jet break
- GRB 050408: Swift XRT analysis
- GRB050408: REM NIR and Optical observation
- GRB 050326 XMM-Newton observation
- GRB050223: analysis of the XMM-Newton observation
- Swift-BAT trigger 107873: No Swift XRT counterpart
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- GRB 050306: REM optical-infrared observations
- GRB 050126: Confirmation of the NIR afterglow candidate
- GRB 050219b: candidate NIR afterglow
- GRB 050219b: Optical and near-IR observations from LCO
- GRB 050126: Detection of NIR afterglow with Keck/NIRC
- GRB 050124: NIR afterglow confirmed with Keck/NIRC
- GRB 050124: NIR Candidates from Keck/NIRC
- GRB050117: Palomar WIRC Ks-band observations
- NIR Observations of GRB 041219
- GRB 041211: Infrared Observations
- GRB041015: Near-Infrared observations
- GRB041006: Near Infrared observations
- GRB040827: analysis of the XMM-Newton observation
- GRB 040827: 2nd epoch of Magellan K-band imaging
- GRB 040827: Detection of NIR afterglow
- GRB 040812: Second epoch CXO Observations
- CXO observation of GRB 040812
- GRB 040730, infrared observations
- SGR 1806-20: no IR variability of the proposed counterparts
- SGR 1806-20, potential NIR counterpart
- GRB 040511: NIR observations with REM
- IBAS GRB alerts 1739, 1740, 1741
- GRB040223: Deep NIR NTT data re-analysis
- GRB 040223: Deep NIR NTT observations
- GRB 040223: REM IJK Observations
- GRB 040223 XMM-Newton observation ...
- GRB 031203 XMM-Newton observation
- GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
- XMM-Newton Observation of GRB031203
- GRB 031203: Deep NIR NTT & VLT observations
- XMM-Newton Observation of GRB031203
- GRB 031203: IR NTTobservations do not confirm REM detection
- GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
- GRB 031203: IR REM Observations
- GRB 031203 XMM-Newton observation