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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').
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"

42 results found.

  1. GRB 251013C: JinShan observations of the non-thermal rebrightening of the optical counterpart
  2. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
  3. GRB 251013C: VLA detection
  4. GRB 251013C: Kilonova-Catcher optical afterglow detection
  5. GRB 251013C: Swift/UVOT Detection
  6. GRB 251013C, GCN Circular 42267, errata corrige
  7. GRB 251013C: detection of a radio counterpart at 15.5GHz
  8. GRB 251013C: SVOM/ECLAIRs refined analysis
  9. GRB 251013C: MAO/AZT-22 optical observations
  10. GRB 251013C: Swift ToO observations
  11. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) further multi-band optical observations
  12. GRB 251013C: OHP/T193 further optical observations and possible color evolution
  13. GRB 251013C: Calapai Observatory, Massa S. Giorgio (Messina), optical observation
  14. GRB 251013C: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an bright optical counterpart
  15. GRB 251013C: MarSEC, optical afterglow photometry
  16. GRB 251013C: OHP/T193 optical afterglow photometry and spectroscopy
  17. GRB 251013C: Bassano Bresciano Observatory optical observations
  18. GRB 251013C: Early and late-time optical counterpart detection by LCO
  19. GRB 251013C: Fermi GBM Observation
  20. GRB 251013C NUTTelA-TAO / BSTI Early Measurements
  21. GRB 251013C: ULL-ASTRO-MASTER detection of the optical afterglow with the LCO 40-cm telescope at Sutherland Observatory
  22. GRB 251013C: Asiago optical observations
  23. GRB 251013C: ABObservatory optical observations
  24. GRB 251013C: J band observations by SYSU 80cm infrared telescope
  25. GRB 251013C: EP-FXT counterpart detection
  26. GRB 251013C: AstroSat CZTI detection
  27. GRB 251013C: ALMA detection
  28. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) detection of the optical counterpart
  29. GRB 251013C: DDOTI detection of the optical afterglow
  30. GRB 20251013C: SLKT optical afterglow photometry
  31. Fermi GRB 251013C: Global MASTER-Net observations report
  32. GRB 251013C: Swift-XRT counterpart detection
  33. GRB 251013C: GOTO optical afterglow detection
  34. GRB 251013C: SAO RAS optical observations
  35. GRB 251013C: LCO optical afterglow detection
  36. GRB 251013C: Optical Observations via Virtual Telescope Project, Italy
  37. GRB 251013C: NOT spectroscopic redshift z = 0.572
  38. GRB 251013C: LAST detection of optical counterpart
  39. GRB 251013C: BOOTES-6 early optical detection
  40. GRB 251013C: SVOM/VT optical observation
  41. GRB 251013C: SVOM detection of a burst
  42. GRB 251013C: Fermi GBM Final Real-time Localization

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