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"27342 results found.
- Erratum of GCN 4983 for GRB 060418 IR follow-up
- GRB 060418 : IR afterglow observations
- GRB 060418: Radio Observations
- GRB060418, BVRcIc field calibration
- GRB060418: Swift/UVOT Observations
- GRB060418: Optical Observations
- GRB 060418: Refined Analysis of the Swift-BAT burst
- GRB 060418, SMARTS continuing afterglow observations
- GRB 060418, SMARTS optical/IR afterglow observations
- GRB060418 : LT optical afterglow observation
- GRB 060418: REM candidate afterglow
- GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
- GRB060413: Swift/UVOT upper limits
- GRB 060413: REM NIR Observations
- GRB 060413: Refined analysis of the Swift-BAT burst
- GRB 060403: MITSuME optical observation
- GRB060403: Optical Limit
- GRB060403: XRT refined analysis
- GRB 060403: Swift/UVOT upper limits
- SGR 1900+14: BAT observations
- GRB 060403: Refined analysis of the Swift-BAT burst
- Konus-Wind observation of the recent SGR 1900+14 activity. Will
- GRB 060403: Swift detection of a burst
- HETE trigger H4044: RTT150 optical observations
- GRB060331: Swift/UVOT upper limits
- Swift XRT observations of the HETE transient H4043
- H4043, an unusual high-energy transient observed by HETE
- GRB 060322: LNA optical limit
- SGR 1900+14: bright burst detected by Konus-Wind on March 28
- INTEGRAL and XMM ToO observations of SGR1900+14
- SGR 1900+14: Swift-BAT detection of a bright outburst
- GRB 060323 : WIDGET simultaneous optical observations
- GRB 060323: Early optical observation at Xinglong
- GRB 060322: Confirmation of Swift XRT afterglow
- GRB060323: NOT optical observations
- GRB 060322: IAC80 optical observations
- GRB 060322: Swift XRT afterglow candidate
- GRB060323: P60 Observations
- GRB 060323: Swift/UVOT Observations
- GRB 060323: optical afterglow confirmed
- GRB060323: NOT observations
- GRB 060323: Optical Observations
- GRB 060323: Refined analysis of the Swift-BAT burst
- GRB 060323: optical observations at TNG
- GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
- GRB 060322: Refined analysis of the Swift-BAT burst
- GRB060323, optical observation
- 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 060218/SN 2006aj, LNA optical observation
- GRB060218: Refined photometric calibration of comparison stars
- GRB 060319: WHT K-band candidate afterglow
- GRB060319: Swift/UVOT upper limits
- GRB 060319: Swift-BAT refined analysis
- GRB 060319 optical observations at TNG
- GRB060319 : Liverpool Telescope optical limit
- GRB060319 - SDSS Pre-burst Observations
- GRB060313: Radio Observations
- GRB 060313: early afterglow NIR upper limits with REM
- GRB 060313: Further analysis of the Swift-BAT bright short hard burst
- GRB 060313: Swift/UVOT Observations
- GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
- GRB 060313, SMARTS optical counterpart?
- GRB 060313, SMARTS optical/IR observations
- GRB060313: optical and near infrared observations with REM
- GRB060218: SARA Observations of SN2006aj
- GRB 060312: Refined analysis of the Swift-BAT burst
- GRB 060218/SN 2006aj, high resolution spectra
- GRB 060312: Swift XRT team refined analysis
- GRB060306: APO Ks-band Imaging Observations
- GRB 060312: ROTSE-III Optical Limits
- Bright short hard GRB 060303: IPN localization and Konus spectrum
- GRB060219: Liverpool Telescope observations
- GRB 060306: MAGNUM observations
- GRB060218: analysis of the XMM-Newton observation
- Swift/UVOT observations of GRB060306
- GRB 060306: Swift-BAT refined analysis
- GRB 060306: Swift-XRT team refined analysis
- GRB 060306: Swift detection of a bright burst
- GRB060218: Ep,i - Eiso correlation
- GRB060223b: optical limit
- GRB 060223b: Swift/UVOT Upper Limits
- GRB 060218/SN 2006aj: K-380 optical observations
- GRB 060218/SN 2006aj, SMARTS optical/IR observations
- GRB 060223B: Swift XRT possible afterglow
- GRB 060218/SN 2006aj: ABT observations
- GRB 060218/SN 2006aj: REM optical and near-infrared observations
- GRB 060218 : Radio upper limits from GMRT
- GRB 060218/SN 2006aj: RBO optical observations
- GRB 060204B: GETS early limit
- GRB 060223A:Xinglong optical limits
- GRB 060223B: Swift-BAT refined analysis
- GRB 060223a: Swift/UVOT refined analysis
- GRB 060223B: Swift detection of a bright burst
- GRB 060223: Swift-BAT refined analysis
- GRB 060223: Swift detection of a burst
- Spectral properties of GRB060218/SN2006aj
- GRB 060219: Swift-BAT refined analysis
- GRB 060218: Decline in r-band flux