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"26338 results found.
- GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
- SN2002ap (SN/GRB?) Echelle spectra
- GRB020127 Optical Observations
- SN 2002ap (SN/GRB?)
- SN 2002ap in M74
- SN2002ap (SN/GRB?) UBVRI Field Photometry
- GRB020127: Chandra Observations and Prospective Counterparts
- GRB020124, optical observations
- GRB020127: Optical observations
- GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
- VLT observations of GRB 020124: The fading optical/near-infrared afterglow
- GRB 020124 Optical Observations
- IPN triangulation of GRB020124 (HETE 1896)
- GRB 020124: Optical afterglow
- GRB020124(=H1896): Localization of a Long GRB by HETE
- Possible optical counterpart to a GRB
- GRB011211: BeppoSAX/GRBM data
- Optical polarization observations for GRB011211
- GRB 011211: Detection of the Probable Host Galaxy
- GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
- Color indices of the afterglow of GRB011211
- GRB011212: Optical observations at Gunma
- GRB 011211, spectrum and optical photometry
- GRB 011130: Optical Observations of X-ray and Radio Sources
- GRB 011130, Radio/X-ray Comparison
- GRB 011211: Evidence for an Optical Break
- GRB 011211: TNG Spectroscopic Observations
- GRB 011212: optical observation at Oslo (relayed)
- GRB 011211, Optical Observations
- GRB011211, BVRI field photometry
- GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
- Fading of the optical source associated of XRF 011211
- GRB011130 (=XRF011130): Further analysis of Chandra Target of
- GRB 011130: Optical Observations of Chandra Sources
- GRB 011130: Optical Observations of Chandra sources
- GRB011130 (XRF011130) Chandra Observations
- GRB011130 (=XRF011130): Scheduled Target of Opportunity
- GRB 011130: Magellan spectroscopy
- GRB011130, optical observations
- GRB 011130, K band observations
- GRB011130 (=XRF011130): Second Revised Localization by HETE
- GRB 011130 I-band Observation
- GRB011130 (XRF011130) optical observations
- GRB011130 (XRF011130) SDSS PT i-band observations
- Detection of the X-ray afterglow of GRB011121 by BeppoSAX
- GRB011130 (=XRF011130): Revised Localization of an X-ray
- GRB001109, Radio Monitoring
- GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
- GRB010921 - Milagro GeV/TeV Observations
- GRB011121: fainter still
- GRB011121
- GRB 011121: Radio Observations
- GRB 011121 J-Band Astrometry
- GRB011121: continued decay
- GRB011121: possible redshift, continued decay
- GRB011121: fading behavior
- IPN triangulation of GRB011121
- GRB 011030: TNG K-band observation
- XRF011030: J and K band observations
- XRF011030: Chandra Observations
- GRB 011030: K-band observations
- GRB011030: Z-band observations
- GRB 011030 R band observations
- The X-ray Flash 011030 ('GRB 011030')
- Non-triggered burst 011030 ("GRB 011030")
- The Radio Afterglow from the X-ray Rich GRB 011030
- GRB010921, optical observation
- GRB011019: Subaru Optical Observations
- GRB 011030 K-band Observations
- GRB010921, optical observations
- GRB 011030, WSRT radio observations
- GRB011030 - further refinement WFC position
- BeppoSAX ALERT: Possible X-ray rich GRB011030
- GRB011019: NEAT Optical Observations
- GRB011019: ROTSE-III optical observations
- GRB 010921, I-band observations
- GRB011019: A Faint, X-ray Rich GRB localized by HETE
- GRB 010921: The afterglow of HETE #1761
- 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
- H1761: A Bright GRB Detected by HETE
- HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
- GRB000926, Host Galaxy Observations
- GRB001109, Host Galaxy Spectroscopic Observations
- Probable SGR or Short Duration GRB Detected by HETE
- GRB 010222: HST observations -- host galaxy and late-time decay
- BeppoSAX/GRBM detection of GRB 010801
- GCN and HETE status
- Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
- BeppoSAX/GRBM detection of GRB010728
- GRB 010222 - WHT BVRI images
- SGR1900+14 burst seen by HETE: BeppoSAX data
- GRB 010629 Optical Observations
- GRB010629: Optical Observations
- SGR1900+14: High Fluence Burst Localized by HETE
- IPN triangulation of GRB010629
- GRB010629: A Burst Localized by HETE
- SGR1900+14: Second Burst Localized by HETE