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"19572 results found.
- GRB 080210: Enhanced Swift-XRT position
- 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: Optical limits from Gemini-South
- Swift detection of AX J1749.1-2639
- GRB 080207: Super-LOTIS observations
- GRB080207: RTT150 Optical Observations
- GRB 080207: REM NIR observations
- GRB080207: Swift/UVOT refined analysis
- GRB 080207: TAROT Calern observatory optical observations
- GRB 080207: Enhanced Swift-XRT position
- GRB 080207: Swift detection of a burst
- GRB 080205: optical observation
- VLA radio upper limit on GRB 080205
- INT+WFC R-band observations of GRB 080205
- IPN localization of very hard GRB 080204
- GRB 080205: Swift XRT refined analysis
- GRB 080205: Swift/UVOT observations
- GRB 080205: Enhanced Swift-XRT position
- 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 080129: Swift-XRT refined analysis
- GRB 080129: KAIT optical limits
- GRB 080129: TAROT La Silla observatory optical observations
- 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 (?): UVOT Upper Limits
- GRB 080121: Swift/UVOT upper limits
- SNe 2008D and 2007uy: Chandra Detections
- GRB 080121: Enhanced Swift-XRT position
- IPN triangulation of GRB080122
- GRB 080121: Nearby SDSS galaxies
- GRB 080121: Swift-BAT detection of a very weak, short burst
- 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
- GRB080120: Swift XRT position
- Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions
- Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
- XRF 080109 / SN 2008D: UKIRT JHK imaging
- optical observations, XRT in NGC 2770
- Gemini-South observations of XRF 080109 / SN 2008D
- Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
- Discovery of Radio Emission from Transient in NGC 2770
- XRF 080109 in NGC2770: NIR observations at TNG
- 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
- Refined Swift-XRT analysis of the transient in NGC 2770
- GRB 071227: optical afterglow
- Further Swift-BAT analysis of GRB 071227
- GRB 071227: Swift-XRT refined analysis
- GRB 071227: VLT probable redshift of the candidate host galaxy
- 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 070429B: Probable host galaxy and redshift
- GRB 071126: Enhanced Swift-XRT position
- GRB071122: Swift/UVOT Observations
- GRB071104: NIR Afterglow Candidate at TNG
- GRB 071122 Swift-XRT refined analysis
- GRB 071122: P60 Optical Afterglow Candidate
- GRB 071122: Swift detection of a burst
- GRB 071118: P60 Observations
- GRB071118 MITSuME OAO optical observation
- GRB 071118: Observations from OSN
- GRB 071117: VLT observations and probable redshift
- Swift/UVOT observations of GRB071118
- Swift XRT follow-up observations of GRB071008
- Swift/UVOT upper limits for GRB 071117
- GRB071118: Swift XRT refined analysis
- GRB 071117: Gemini Optical Afterglow Discovery
- GRB 071117: TAROT La Silla observatory optical observations
- GRB 071118: Swift detection of a burst
- GRB 071117: Gemini Observations
- GRB 071117: Initial Swift/UVOT observations
- Swift detection of MXB 0656-072
- GRB 071112C: Optical and NIR data observed with KANATA
- GRB 071112C: emission lines and refined VLT redshift
- GRB 071112C MITSuME Akeno early optical observation
- GRB 071112C: SARA upper limit
- GRB 071112C : Second Epoch Lulin R-band observations
- GRB071112C MITSuME Okayama Optical Observation