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"28063 results found.
- 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: 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
- GRB 080210: Swift detection of a burst with optical afterglow
- GRB 080210: TAROT La Silla observatory optical detection
- GRB 080207: GROND upper limits
- 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
- GRB 080205 optical upper limit
- VLA radio upper limit on GRB 080205
- INT+WFC R-band observations of GRB 080205
- 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
- GRB 080130: further Swift XRT observations confirm fading source
- 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: Swift-XRT refined analysis
- 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: 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 080121: Swift/UVOT upper limits
- SNe 2008D and 2007uy: Chandra Detections
- GRB 080121 position was incorrect
- GRB 080121: Enhanced Swift-XRT position
- GRB 080121: Swift-BAT detection of a very weak, short burst
- GRB 080123: Swift-XRT refined analysis
- GRB 080123: Swift/UVOT refined analysis
- GRB 080123: Enhanced Swift-XRT position
- GRB 080123: Swift detection of a short burst
- GRB 080120: GROND confirmation of the optical afterglow
- VLA radio upper limit on GRB 080120
- GRB 080120: Swift-XRT refined analysis
- UVOT detection of GRB080120
- GRB 080120: GROND detection
- GRB080120: Swift XRT position
- XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
- XRF 080109 / SN 2008D: WSRT Radio Detection
- NGC 2770B has the same redshift as NGC 2770
- Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
- optical observations, XRT in NGC 2770
- Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
- XRB 080109/SN 2008D: Early decline in brightness and change in colors
- XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
- XRF 080109 in NGC2770: Detectable Superluminal Motion
- Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
- XRF in NGC 2770: Search for X-ray periodicity
- Refined Swift-XRT analysis of the transient in NGC 2770
- Transient in NGC 2770: spectroscopic evidence for a SN
- Early OT detection of XRF in NGC 2770 in Asiago frames
- Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
- GRB 071227: optical afterglow
- GRB 071227: Swift-XRT refined analysis
- GRB 071227: VLT probable redshift of the candidate host galaxy
- GRB 071227: Magellan observations
- GRB071227: Swift/UVOT refined analysis
- GRB 071227: REM NIR and Optical observations
- GRB 071227: Swift detection of a burst
- GRB071020: optical observations
- GRB 070429B: Possible UVOT Detection of an Optical Afterglow
- GRB 071208?: Swift detection of a possible burst
- GRB 070429B: Probable host galaxy and redshift
- GRB 071129: Swift detection of a burst
- GRB 071112C: Optical/NIR observations
- Disregard the "GRB 071126" position
- GRB 071126: Enhanced Swift-XRT position