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"19549 results found.
- GRB020406(?), optical observations
- GRB020405, Radio Observations
- GRB 020405, U-band observations
- GRB020331 NIR observation at KPNO (re-submission)
- GRB02033 NIR observation at KPNO
- GRB020331 field photometry
- GRB 020331, NIR observations
- GRB020331(=H1963): The "Easter" Burst Detected by HETE
- GRB 020322: BeppoSAX observations of the X-ray afterglow
- GRB011211: HST Observations of Optical Afterglow and Host Galaxy
- Near-Infrared Observations of GRB020322 at TIRGO
- GRB 020322: Optical Observations
- GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
- GRB 020321: Optical observations
- GRB020317 BVRI field photometry
- GRB011211 revised BVRI field photometry
- GRB020305 BVRI field photometry
- GRB020322 BVRI field photometry
- GRB 020322: Optical Sources and Improved Astrometry
- GRB020317: optical observations
- GRB020321 optical observations
- GRB020321: a faint BeppoSAX detection
- GRB 020317 : KISO Optical Observations
- GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
- GRB 020305: Optical Observations
- GRB020317, optical observations
- GRB 020317: Optical observations
- GRB 011121: Third HST Epoch
- GRB020305: Properties of the Candidate Optical Afterglow
- GRB011130 (XRF011130) Second Epoch Chandra Observations
- XRF/GRB 011030: Detection of the Probable Host Galaxy
- GRB020305, optical observations
- GRB020305 (=H1939): Localization of a GRB by HETE
- HST Imaging of the afterglow and host of GRB 011121
- IPN detection and localization of Cygnus X-1 flares
- SGR1900+14 activity
- GRB020124 BVRI field photometry
- SN2002ap (SN/GRB?) optical spectrographic observations
- GRB020127 Optical Observations
- SN2002ap (SN/GRB?) UBVRI Field Photometry
- GRB020127: Chandra Observations and Prospective Counterparts
- pre-SN2002ap (SN/GRB?) imaging of M74
- GRB020124, optical observations
- GRB020127: Optical observations
- 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
- GRB020124(=H1896): Localization of a Long GRB by HETE
- Possible optical counterpart to a GRB
- GRB011212, Optical Observations
- GRB011211: BeppoSAX/GRBM data
- Optical polarization observations for GRB011211
- GRB 011130: Optical Observations of X-ray and Radio Sources
- GRB 011212: optical observation at Asiago
- GRB 011211: Evidence for an Optical Break
- GRB 011212: optical observation at Oslo (relayed)
- GRB 011211: Optical Spectroscopy
- 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
- GRB011130 (=XRF011130): Further analysis of Chandra Target of
- GRB011130 (XRF011130) Chandra Observations
- GRB011130 (=XRF011130): Scheduled Target of Opportunity
- GRB 011130, K band observations
- GRB011130 (XRF011130) SDSS PT i-band observations
- XRF011130: Infrared Observations
- 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
- GRB011030, optical observation
- XRF011030: Chandra Observations
- GRB011030: Z-band observations
- GRB 011030 I-band Observation
- 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
- GRB011019: Subaru Optical Observations
- GRB011030 - further refinement WFC position
- 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
- GRB010921: Spectroscopy of the Host Galaxy
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- GRB010928(=H1770): Localization of a Long GRB by HETE
- GRB010923(=H1764): A Short Duration GRB Detected by HETE
- GRB010921, negative optical observations