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.
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"26301 results found.
- Lowell/Perkins observation of GRB 991216
- GRB 991208 Keck Spectroscopy
- GRB 991216: Extremely bright BATSE burst
- R-band Observations of GRB991208 at TNG
- GRB991208, optical observations
- GRB 991208 Keck Spectroscopy
- GRB991208 - millimeter detection
- GRB991208 15-GHz observations
- GRB991208, optical observations
- GRB 991208 Optical Decay
- GRB 991208 optical observations
- GRB 991208 optical observations
- IPN localization of GRB991208
- Optical Observations of GRB991105
- GRB991106: BeppoSAX/BATSE results
- GRB 991106, optical observations
- GRB991106, near-infrared observations
- BeppoSAX NFI Observation of GRB991106
- GRB 991105: BATSE Observations
- IPN localization of GRB991105
- GRB 991106 Optical Observations
- GRB 991105, optical observations
- GRB 991106, optical observations
- BeppoSAX GRB Alert: GRB991106
- BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
- GRB ALERT: GRB991105
- GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
- GRB 991014, radio observations
- GRB991014 BATSE Observations
- GRB 991014, optical observations
- IPN/NFI error box for GRB991014
- BeppoSAX ALERT: GRB991014
- GRB 990915 optical observations
- GRB 990907 optical observations
- GRB990907 and 990908
- GRB990908, another BeppoSAX-GRBM/WFC burst detection
- BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
- GRB 990712 Late Optical Decay and Host Galaxy
- GRB 990712, Optical Observation
- GRB990806 BeppoSAX follow up
- GRB990806: BATSE Observations
- Optical Observations of GRB990806
- GRB 990806, Optical Observations
- BeppoSAX ALERT GRB990806: Summer GRB
- GRB 990712 Optical Observations
- GRB 990712 Optical Decay: Indication of Bright Host Galaxy
- Late-time HST/STIS Observations of GRB 990510
- Refined BeppoSAX-WFC position of GRB990712
- BeppoSAX NFI Observation of GRB990705
- BeppoSAX NFI Observation of GRB990705
- GRB 990705, radio observations
- GRB 990704, optical observations
- GRB990704
- GRB990704, optical observations
- Refined BeppoSAX-WFC position of GRB990704
- GRB990704: BeppoSAX detection
- BeppoSAX NFI Observation of GRB990627 X-ray afterglow
- Optical Observations of GRB990627
- GRB 990627, radio observations
- GRB990627: BeppoSAX-WFC final location
- BeppoSAX: GRB990625
- Late-time HST/STIS Observation of GRB 990123
- X-ray/GRB 1SAX J0835.9+5118, Optical Observation
- Late Afterglows of GRBs 990510, 990123
- X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
- X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
- X-ray/GRB 1SAX J0835.9+5118, Optical Observations
- X-ray/GRB 1SAX J0835.9+5118, Optical Observation
- X-ray/GRB 1SAX J0835.9+5118, Optical Observation
- X-ray/GRB 1SAX J0835.9+5118, Optical Observation
- radio observations of X-ray/GRB transient field
- optical observation of the X-ray/GRB transient SAX J0835.9+5118
- Optical report on X-ray/GRB transient
- radio detection of X-ray/GRB transient
- BeppoSAX: A new fast X-ray transient
- GRB990510: photometric and spectroscopic observations with the VLT
- GRB 990510: optical observations
- GRB 990506 R band observations
- VLT spectrum of GRB990510
- GRB 990510: Broad Band Break
- GRB 990510: BATSE Observations
- GRB 990510 Optical Observations
- GRB 990510, BVI photometry
- GRB 990510 optical observations
- GRB 990510: BeppoSAX/GRBM observations
- GRB990510 optical observations
- GRB 990510 optical observations
- GRB 990510 optical observations
- GRB 990506: BATSE Observations
- GRB 990506, optical observations
- GRB 990510: Final BeppoSAX-WFC Coordinates
- GRB 990506, Optical Observations
- GRB 990506 optical observations
- GRB 990506 optical observations
- GRB990506 observation plan
- Refined IPN error box for GRB990506
- GRB 990506: Limits on the possible optical transient
- GRB 990506, optical observations from +1 to +3 hours
- IPN localization for GRB990506
- GRB 970228: Redshift and properties of the host galaxy