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"26338 results found.
- Confirmation of IPN position for GRB001204
- IPN triangulation of GRB001204 (short/hard)
- GRB 001105, further optical observations
- GRB001120: Gunn-i observations
- GRB001120, optical observations
- WSRT 4.8 GHz observations of GRB001109
- IPN triangulation of GRB001120
- Optical/NIR observations of GRB001109
- GRB 001109: deep JHK upper limits
- GRB 001109 X-ray afterglow with BeppoSAX
- GRB001109, R-band optical observations
- BeppoSAX ALERT: GRB001109
- IPN TRIANGULATION OF GRB001105
- GRB 991208: HST Imaging of the Host Galaxy
- GRB000926: R-image of the host galaxy
- GRB 001025B, I-band observations
- XMM-Newton observation of GRB001025
- IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
- IPN triangulation of GRB001025
- ASM Localization of GRB 001025
- GRB001007, Radio observations
- IPN TRIANGULATION OF GRB001020
- GRB001019, Optical Observations
- GRB001018, Gamma Ray Observations
- IPN TRIANGULATION OF GRB001019
- IPN TRIANGULATION OF GRB001018
- IPN TRIANGULATION OF GRB 001017
- GRB 000926: Improved Absorber Redshift
- HETE positions added to GCN
- BeppoSAX ALERT: GRB001011
- GRB 001007, BVR-band observations
- GRB000926 - Amateur Optical Observations
- CONCAM null result on GRB001005
- IPN triangulation of GRB001007
- HETE-2 Launches Successfully
- IPN triangulation of GRB001005
- HETE-2 48 hour Launch Delay
- GRB 000926 Chandra Observation
- IPN triangulation of GRB 001004
- Public availability of BeppoSAX data of GRB000926
- GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
- GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
- GRB000926 - Optical observations
- GRB 000926, Optical Decay
- GRB000926 - Optical observations
- GRB000926 - Optical observations
- GRB 000926, Optical Observations
- GRB000926 - Optical observations
- GRB000911: optical VLT observations
- GRB000926 K'-band Observation
- GRB000926 optical observations
- GRB000926 - Optical observations
- Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
- GRB 000926, optical observation by Oksanen (vsnet-grb)
- GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
- Spectroscopic Redshift of GRB 000926
- GRB000926, radio observations
- GRB 000926: Optical candidate
- Optical candidate for GRB000926
- IPN triangulation of GRB000926
- GRB 000911, BVRI field photometry
- IPN triangulation of GRB000925
- GRB000911, Radio and Optical observations
- IPN triangulation of GRB000911
- IPN triangulation of GRB000910
- GRB 000830: Optical observations
- GRB000210, Optical observations
- Chandra Position of GRB000210
- IPN triangulation of GRB000830
- HST/STIS observations of the host galaxy of GRB 980329
- IPN localization of GRB000820
- GRB000812, TNG R-band observations
- GRB000801 & GRB000730, Gamma Ray Observations
- GRB000730, Gamma Ray Observations
- IPN localization of GRB000812
- IPN localization of GRB000811
- GRB000801, Gamma Ray Observations
- GRB000301C, UBVI optical observations
- IPN localization of GRB000801
- IPN localization of GRB000730B
- IPN localization of GRB000730
- GRB 990510: Possible detection of a host galaxy
- IPN localization of GRB000727
- GRB 990712: Late time HST/STIS Observations
- GRB 991216, HST/STIS observations
- GRB981226, HST/STIS observations of the host galaxy
- GRB000630, optical observations
- GRB000630, Optical Observations
- GRB000630, optical observations
- GRB000630, optical observations
- GRB000630: Optical observations
- GRB000630, Radio Observations
- IPN triangulation of GRB000630
- GRB000418, HST/STIS Observations
- GRB 990506, HST/STIS Observations of the Host Galaxy
- GRB000623
- GRB000615: H-band observations
- IPN annulus for GRB000620
- GRB 000615: NIR further observations
- BeppoSAX ALERT: GRB000620