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"27401 results found.
- 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
- GRB060218: UV Detection and Light Curves
- GRB060219: SARA Observations
- GRB 060219: Swift/UVOT Upper Limits
- GRB 060219: Swift-XRT Team refined analysis
- GRB 051221B: Swift-XRT Team Refined Analysis
- GRB060218: Radio Afterglow Discovery
- GRB060219: SDSS pre-burst observations
- GRB 060219: Swift-BAT detection of a weak burst
- Oddball GRB 060218, transient or GRB?
- GRB060218: Swift/XRT Team preliminary analysis of the possible burst
- GRB 060218: Pre-burst detection of a possible host galaxy
- Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
- GRB 060211B: Swift/UVOT Upper Limits
- GRB060218 : SDSS pre-burst observations
- GRB 060218: Swift-BAT detection of a possible burst
- GRB 060213: optical afterglow not confirmed
- Swift UVOT observations of GRB060213
- GRB 060211B: Skynet Observations
- GRB060213: Swift XRT observations and possible afterglow candidate
- GRB 060213: IPN localization
- GRB060211B: REM optical and NIR observations
- GRB 060211A: Further refined analysis of the Swift burst
- GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
- GRB 060211b: P60 Observations
- GRB 060211A: Partial refined analysis on the Swift-BAT burst
- GRB 050826: Optical Afterglow and Host Galaxy
- GRB 060210: Further refined analysis of the Swift-BAT burst
- GRB 060211B: Swift/BAT refined analysis
- GRB060210: Swift/UVOT Upper Limits
- GRB 060211B: Swift-XRT Team refined analysis
- GRB 060210: Optical Observations
- GRB 060211: Swift detection of a long burst
- GRB 060210: Refined analysis of the Swift-BAT burst
- GRB060210: Swift XRT Refined Analysis
- GRB 060210 : Xinglong and Lulin optical limit
- GRB 060210: optical evolution
- GRB 060210: Swift detection of a burst
- GRB060210: Optical afterglow
- GRB 060209 : TAROT optical observation
- GRB 060203: Swift/UVOT upper limits
- GRB 060121 : WIDGET Pre-trigger limit