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"28047 results found.
- GRB 020127, I-band observations starting 3.14-hr after the event
- GRB010921 Optical Observations
- GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
- GRB020124: Optical observations
- GRB 020124: Optical observations
- GRB 020124: Optical afterglow
- GRB020124(=H1896): Localization of a Long GRB by HETE
- Possible optical counterpart to a GRB
- GRB011212, Optical Observations
- Optical polarization observations for GRB011211
- GRB 011211: Detection of the Probable Host Galaxy
- GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
- GRB 011130: Optical Observations of X-ray and Radio Sources
- GRB 011212: optical observation at Asiago
- GRB 011211: Evidence for an Optical Break
- GRB 011211: TNG Spectroscopic Observations
- optical follow-up of GRB(XRF) 011211
- GRB 011212: optical observation at Oslo (relayed)
- GRB 011211, Optical Observations
- GRB011212, BVRI field photometry
- GRB011211, BVRI field photometry
- GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
- Fading of the optical source associated of XRF 011211
- GRB 011211 Optical Observations: Likely Afterglow
- GRB011130 (=XRF011130): Further analysis of Chandra Target of
- GRB011130 (XRF011130) Chandra Observations
- GRB011130 (=XRF011130): Scheduled Target of Opportunity
- GRB 011130, K band observations
- GRB011130, optical observations
- GRB011130 (=XRF011130): Second Revised Localization by HETE
- GRB011130 (XRF011130) SDSS PT i-band observations
- XRF011130: Infrared Observations
- GRB 011121
- GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
- GRB 011121: J-band observations
- GRB 011121: NIR observations, host galaxy?
- GRB011121: UBRI Observations
- GRB 011121 J-Band Astrometry
- GRB 011121: Detection of Bright IR Counterpart
- GRB011121: possible redshift, continued decay
- GRB 011030: TNG K-band observation
- XRF011030: J and K band observations
- XRF011030: Chandra Observations
- GRB011030: Z-band observations
- GRB 011030 R band observations
- GRB 011030 I-band Observation
- The X-ray Flash 011030 ('GRB 011030')
- Non-triggered burst 011030 ("GRB 011030")
- The Radio Afterglow from the X-ray Rich GRB 011030
- GRB 010921: HST Detection of the Afterglow and Host Galaxy
- GRB 970828: HST Observations of the Host Galaxy
- GRB 000131: HST Detection of the Host Galaxy
- GRB 970828: HST Observations of the Host Galaxy
- Optical observation of SGR 1806-20 at the 6-m SAO telescope
- GRB011019: Subaru Optical Observations
- GRB 011030 I-band Observations
- GRB 011030 K-band Observations
- GRB010921, optical observations
- GRB011030 - further refinement WFC position
- GRB 011030, Radio observations
- GRB011030: radio search
- GRB 010921: Possible supernova component
- GRB010921, optical observation at early time
- GRB 010921, I-band observations
- GRB011019, optical observations
- GRB011019: A Faint, X-ray Rich GRB localized by HETE
- GRB 010921: The afterglow of HETE #1761
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- GRB010923 as seen by BeppoSAX GRBM
- GRB010928(=H1770): Localization of a Long GRB by HETE
- GRB010923(=H1764): A Short Duration GRB Detected by HETE
- GRB010921, negative optical observations
- GRB010921 field photometry
- H1761: A Bright GRB Detected by HETE
- GRB000926, Host Galaxy Observations
- GRB001109, Host Galaxy Spectroscopic Observations
- Probable SGR or Short Duration GRB Detected by HETE
- GCN and HETE status
- Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
- GRB 010222 - WHT BVRI images
- SGR1900+14 burst seen by HETE: BeppoSAX data
- GRB 010629 Optical Observations
- SGR1900+14: High Fluence Burst Localized by HETE
- GRB010629, optical observations
- GRB010629: A Burst Localized by HETE
- SGR1900+14: Second Burst Localized by HETE
- SGR1900+14: A Burst Localized by HETE
- SGR1806-20: A Second, Intense Burst Localized by HETE
- SGR1806-20: Localization by HETE
- HETE Fully-Automated GCN Notices
- GRB000301C: Late-time HST/STIS observation
- GRB010518: a faint BeppoSAX detection
- GRB000418: HST/STIS Second-epoch Observations
- X-ray precursors to the large flare from SGR 1900+14
- GRB010427, Gamma Ray Observations
- SGR 1900+14: No evidence of extended X-ray emission
- SGR 1900+14 : RXTE observations
- BeppoSAX/NFI Follow-up Observation of SGR 1900+14
- SGR 1900+14: Correction to GCN 1049