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"3402 results found.
- GRB 230606A: Swift-XRT refined Analysis
- LIGO/Virgo S230518h: Swift XRT observations, 8 X-ray sources
- GRB 230512A: Swift-XRT observations
- GRB 230510A: Swift-XRT refined Analysis
- GRB 230506C: Swift-XRT refined Analysis
- GRB 230506C: Swift/UVOT Upper Limits
- GRB 230506B: Swift-XRT refined Analysis
- GRB 230506C: Swift-XRT analysis
- GRB 230427A: Swift-XRT refined Analysis
- GRB 230423A: Swift-XRT refined Analysis
- GRB 230420A: Swift-XRT refined Analysis
- GRB 230414B: Swift-XRT refined Analysis
- GRB 230409B: Swift-XRT refined Analysis
- GRB 230405B: Swift-XRT refined Analysis
- GRB 230307A: Chandra late-time detection of the X-ray afterglow
- GRB 230328B: 3.6m DOT multiband optical observation
- GRB 230328B: Swift-XRT refined Analysis
- GRB 230325A: Swift-XRT refined Analysis
- GRB 230322B: Swift-XRT refined Analysis
- GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
- GRB 230307A: Swift/UVOT detection
- GRB 230307A: Swift-XRT afterglow detection
- GRB 230307A: Swift/BAT upper limits on the early afterglow
- GRB 230307A: Swift-XRT observations
- GRB 230228A: Swift-XRT refined Analysis
- GRB 230217A: Swift/UVOT Upper Limits
- GRB 230217A: Swift-XRT afterglow detection
- GRB 230217A: Swift-XRT observations
- GRB 230216A: Swift-XRT refined Analysis
- Swift Trigger 1153670 is probably not a GRB
- GRB 221009A: Continued Swift Observations
- GRB 230204B: Swift/UVOT Upper Limits
- GRB 230204B: Swift-XRT afterglow detection
- GRB 230205A: Swift-XRT refined Analysis
- GRB 230204A: Swift-XRT refined Analysis
- GRB 230123A: Swift-XRT refined Analysis
- GRB 230116C: Swift-XRT observations
- GRB 230116D: Swift-XRT refined Analysis
- GRB 221231A: Swift-XRT afterglow detection
- GRB 221231A: Swift-XRT observations
- GRB 221226B: Swift-XRT refined Analysis
- GRB 221216A: Swift-XRT refined Analysis
- GRB 221215A: Swift-XRT observations
- GRB 221206B: Swift-XRT observations
- GRB 221202A: Swift-XRT refined Analysis
- GRB 221201A: Swift-XRT refined Analysis
- GRB 221120A: Swift-XRT refined Analysis
- GRB 221119A: Fermi-LAT detection
- GRB 221110A: Swift-XRT refined Analysis
- GRB 221028A: Swift-XRT refined Analysis
- GRB 221027B: Swift-XRT refined Analysis
- GRB 221022A: Swift-XRT observations
- GRB 221024A: Swift-XRT refined Analysis
- GRB 221017A: Swift-XRT observations
- GRB 221009A: Second epoch of NuSTAR data
- GRB 221016A: Swift-XRT refined Analysis
- MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
- GRB 221009A: IXPE preliminary upper limits of X-ray polarization
- GRB 221006A: Swift-XRT afterglow detection
- GRB 221009A: NuSTAR Detection
- GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
- GRB 221009A: Continued Swift/XRT observations
- GRB 221009A: Swift-XRT refined Analysis
- GRB 221008A: Swift-XRT observations
- GRB 221006A: Swift-XRT observations
- GRB 220930A: Swift-XRT refined Analysis
- GRB 220921A: Swift-XRT Observations
- GRB 220909A: Swift-XRT observations
- GRB 220831A: Gemini-South Infrared Observations
- GRB 220907A: Swift-XRT refined Analysis
- GRB 220907A: Swift-XRT position
- GRB 220831A: Swift-UVOT Upper Limits
- GRB 220831A: Swift-XRT observations
- GRB 220826A: Swift-XRT refined Analysis
- GRB 220810A: Further Swift-XRT observations
- GRB 220813A: Swift-XRT refined Analysis
- GRB 220810A: Swift-XRT observations
- GRB 220730A: Swift-XRT afterglow detection
- GRB 220730A: Swift-XRT observations
- GRB 220715B: Swift-XRT refined Analysis
- GRB 220714B: Swift-XRT refined Analysis
- GRB 220711B: 10.4 m GTC(+EMIR) observations
- GRB 220711B: 10.4 m GTC(+EMIR) observations
- GRB 220710A: Swift-XRT afterglow detection
- GRB 220711B: Swift-XRT refined Analysis
- GRB 220708A: Swift-XRT refined Analysis
- GRB 220708B: Swift-XRT afterglow detection
- GRB 220706A: Swift-XRT refined Analysis
- GRB 220701A: Swift-XRT refined Analysis
- GRB 220627A: Swift-XRT afterglow detection
- Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
- GRB 220611A: X-ray afterglow Chandra sub-arcsecond localization
- GRB 220623A: Swift-XRT refined Analysis
- GRB 220611A: Continued Gemini Infrared Observations
- GRB 220618A: Swift-XRT refined Analysis
- GRB 220617A: Swift-XRT observations
- GRB 220611A: Gemini Ks counterpart detection
- GRB 220611A: Gemini South Infrared Detection
- GRB 220611A: Swift-XRT refined Analysis
- GRB 220606B: Swift follow-up observations