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"- Swift-XRT and UVOT observations of the IPN burst GRB 080211
- GRB 080212: VLT optical rapid decay
- GRB 080212: REM refined analysis
- Konus-Wind observation of GRB 080211
- VLA radio upper limit on GRB 080212
- Swift/UVOT refined analysis of GRB080212
- GRB 080212, Swift-BAT refined analysis
- GRB080212: Optical afterglow candidate observed by MITSuME Telescope
- GRB 080212: Gemini-South optical observations
- GRB 080212: GROND detects afterglow
- GRB 080212: REM NIR afterglow?
- GRB 080212: optical observations
- GRB 080212: Enhanced Swift-XRT position
- GRB 080212: Swift-XRT Team refined analysis
- GRB 080210: Keck photometry
- VLA non-detection of GRB 080210
- GRB 080212: Swift detection of a burst
- IPN localization of GRB 080211
- GRB 080212: DSS/2MASS Galaxy at XRT position
- GRB 080207: VLT NIR early upper limits
- GRB 080210: Swift/UVOT Refined Analysis
- GRB 080207: optical observations.
- GRB 080210: Hobby-Eberly Telescope Absorption Spectroscopy
- GRB 080210, Swift-BAT refined analysis
- GRB 080210: Super-LOTIS observations
- GRB 080210: Swift-XRT Refined Analysis
- GRB 080210: VLT redshift
- GRB 080210: Enhanced Swift-XRT position
- GRB 080210: Rapid PROMPT Detections
- GRB 080210: GOND detection in all bands and redshift upper limit
- GRB080210 - SDSS Pre-Burst Observations
- GRB 080210: Swift detection of a burst with optical afterglow
- GRB 080210: TAROT La Silla observatory optical detection
- GRB 080207: GROND upper limits
- GRB 080205: GAO 150cm telescope Optical limit
- GRB 080207, Swift-BAT refined analysis
- GRB 080207: Optical limits from Gemini-South
- GRB 080205: RTT150 optical observations
- Swift detection of AX J1749.1-2639
- GRB 080207: Super-LOTIS observations
- GRB 080207, Swift-BAT refined analysis
- Swift Trigger 302777 is not a GRB
- GRB080207: RTT150 Optical Observations
- GRB 080207: REM NIR observations
- GRB080207: Swift/UVOT refined analysis
- GRB 080207: TAROT Calern observatory optical observations
- GRB 080207: Swift-XRT Refined Analysis
- GRB 080207: Enhanced Swift-XRT position
- GRB 080207: Swift detection of a burst
- Konus-Wind observation of GRB 080204
- GRB 080205 optical upper limit
- GRB 080205: MASTER optical observation
- GRB 080205: optical observation
- VLA radio upper limit on GRB 080205
- INT+WFC R-band observations of GRB 080205
- GRB 080205, Swift-BAT refined analysis
- IPN localization of very hard GRB 080204
- GRB 080205: Swift XRT refined analysis
- GRB 080205: OA evolution from KAIT observations
- GRB 080205: Swift/UVOT observations
- GRB 080205: Enhanced Swift-XRT position
- GRB 080205: KAIT OA detection
- GRB 080205: Swift detection of a burst
- Swift-BAT Trigger #302454, correction of GCN notice, update on AX J1749.1-2639
- GRB 080130: Swift-BAT refined analysis
- GRB 080130: further Swift XRT observations confirm fading source
- GRB 080129: Swift/UVOT Refined Upper Limits
- Swift/UVOT observations of GRB080130
- GRB 080130: REM NIR observations
- GRB 080130(?): Swift XRT observation
- GRB 080130?: Detection of a possible burst by BATSS
- GRB 080129: Optical observations from OSN
- GRB 080129: Swift-XRT refined analysis
- X-ray transient in NGC 2770: RTT150 optical observations
- GRB 080129: KAIT optical limits
- GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
- GRB 080129: optical limit by Pi of the Sky
- GRB 080129, Swift-BAT refined analysis
- GRB 080129: TAROT La Silla observatory optical observations
- GRB 080129: Gemini-South photometry
- GRB 080129: GROND detection in all bands, and fading
- GRB 080129: GROND detection of the optical/NIR afterglow, and fading
- GRB 080129: Enhanced Swift-XRT position
- GRB 080129: Gemini-South Imaging Observations
- GRB 080129: Swift XRT position
- GRB 080129 (?): UVOT Upper Limits
- GRB 080129 (?): Swift detection of a possible burst
- A new website of high-level data products for Swift GRBs
- GRB 080121: Upper limit on X-ray afterglow
- GRB 080123 : Suzaku WAM observation of the prompt emission
- Swift trigger(=301779) is not a GRB
- Transient 080109/SN 2008D: Spectroscopic Evolution
- GRB 080122: pseudo-z= 1.93 from prompt emission spectrum
- Konus-Wind observation of GRB 080122
- GRB 080122 : Suzaku WAM observation of the prompt emission
- GRB 080121: Swift/UVOT upper limits
- SNe 2008D and 2007uy: Chandra Detections
- GRB 080121 position was incorrect
- GRB 080121: Enhanced Swift-XRT position
- Two non-burst Swift SubThreshold triggers