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"
18732 results found.
- GRB060501: Swift UVOT followup observations
- GRB060502: Super-LOTIS Observations
- GRB 060502: Swift detection of a burst with an optical counterpart
- GRB 060501: MDM Observations
- GRB060501: Super-LOTIS observations
- GRB060501: P60 imaging and afterglow candidate
- GRB 060501: Refined analysis of the Swift-BAT burst
- GRB060501: Swift XRT position
- GRB 060501: ROTSE-III Optical Limits
- GRB 060501: Swift detection of a burst
- GRB060428B: optical observation
- GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
- GRB 060428B: MDM Observations
- GRB060428B: Swift XRT Team refined analysis
- GRB 060427B: IPN localization of a short hard burst
- GRB 060428B: Refined analysis of the Swift-BAT burst
- GRB 060428B: KAIT observations
- GRB060428A: Swift/UVOT observations.
- GRB060428B, optical observation
- GRB 060428A: Refined analysis of the Swift-BAT burst
- GRB060428A: Swift XRT Team refined analysis
- GRB 060428B: Swift detection of a burst
- GRB 060428: Swift detection of a burst
- GRB 060427: NOT observations
- GRB 060427: Swift/UVOT upper limits.
- GRB 060427: Refined analysis of the Swift-BAT burst
- GRB060427: Swift XRT Team refined analysis
- GRB060418: Swift XRT Team Further Refined Analysis
- GRB 060427, optical observation
- GRB 060427: Swift detection of a burst
- GRB 060425: IPN localization and KW spectrum of a short, hard burst
- GRB 060424: Refined analysis of the Swift-BAT burst
- GRB 060424: Swift detection of a burst
- Swift-BAT detection of Mrk 421
- GRB060421: Swift/UVOT observations
- GRB 060421: Swift-BAT Refined Analysis
- GRB 060421: Swift-XRT refined analysis
- GRB 060418: prediction of t_break
- Konus-Wind observation of GRB 060418
- GRB(?)060421:MASTER optical limit
- GRB(?)060421 : XRT position
- Possible GRB060421: BART limits
- GRB(?) 060421: Swift detection of a burst
- GRB060418: Swift/UVOT Observations
- GRB 060418: FRAM early afterglow observation
- GRB 060418: Refined Analysis of the Swift-BAT burst
- VLT/UVES observations of GRB060418
- GRB060418: Swift XRT Team Refined Analysis
- GRB060418: Magellan/MIKE Spectroscopic Redshift
- GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
- SGR 1900+14: Refined analysis of the Swift-BAT outburst
- GRB060413: Swift/UVOT upper limits
- SGR 1900+14: Swift detection of an outburst
- GRB 060413: Refined analysis of the Swift-BAT burst
- GRB 060413: XRT refined analysis
- GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
- GRB 060413: Swift detection of a burst
- GRB060403: XRT refined analysis
- GRB 060403: Swift/UVOT upper limits
- SGR 1900+14: BAT observations
- GRB 060403: Refined analysis of the Swift-BAT burst
- GRB060403: Swift XRT refined position
- Konus-Wind observation of the recent SGR 1900+14 activity. Will
- GRB 060403: Swift detection of a burst
- GRB060331: Swift/UVOT upper limits
- Swift XRT observations of the HETE transient H4043
- SGR 1900+14: bright burst detected by Konus-Wind on March 28
- SGR 1900+14: Swift-BAT detection of a cluster of outbursts
- SGR 1900+14: Swift-BAT detection of a bright outburst
- GRB 060323 : WIDGET simultaneous optical observations
- GRB 060322: Confirmation of Swift XRT afterglow
- GRB060323: optical limit
- SGR 1900+14: CORRECTION to GCN 4923
- SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
- SGR 1900+14: Swift detection of renewed activity
- GRB060323: NOT optical observations
- GRB 060322: IAC80 optical observations
- GRB 060322: Swift XRT afterglow candidate
- GRB 060323: Swift/UVOT Observations
- GRB060323: NOT observations
- GRB 060323: Refined analysis of the Swift-BAT burst
- GRB 060323: Swift XRT refined analysis
- GRB 060323: Swift/XRT position
- GRB 060322: Refined analysis of the Swift-BAT burst
- GRB060323 - SDSS Pre-Burst Observations
- GRB 060323: Swift detection of a burst with a possible optical afterglow
- GRB 060322: Swift-BAT detection of a 200-sec burst
- GRB 060319: IAC-80 optical observations
- GRB060319: Swift XRT refined analysis
- GRB060319: Swift/UVOT upper limits
- GRB 060319: Swift-BAT refined analysis
- GRB060319: Swift/XRT position
- GRB 060319: Swift detection of a burst
- Konus-Wind observation of GRB 060313
- GRB 060313: Further analysis of the Swift-BAT bright short hard burst
- GRB 060313: Swift/UVOT Observations
- GRB 060313: Swift-XRT team refined analysis
- GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
- GRB 060313: Swift XRT position
- GRB060313: optical and near infrared observations with REM