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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"

50 results found.

  1. GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
  2. GRB 240825A: LBT optical observations
  3. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  4. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  5. GRB 240825A: 7DT Optical Upper Limit
  6. GRB 240825A: Montarrenti Observatory optical follow-up observations
  7. GRB 240825A: ATCA Detection of Radio Counterpart
  8. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  9. GRB 240825A: MeerLICHT afterglow detection
  10. GRB 240825A: TSHAO Optical Upper Limit
  11. GRB 240825A: SOAR observations
  12. GRB 240825A: Swift-BAT refined analysis
  13. GRB 240825A: MeerKAT detection
  14. GRB 240825A: SVOM/VT optical detection
  15. GRB 240825A: further SAO RAS optical observations
  16. GRB 240825A: iTelescope optical observations
  17. GRB 240825A: Upper limits from a neutrino search with IceCube
  18. GRB 240825A: VLA detection
  19. GRB 240825A: GECAM detection
  20. GRB 240825A: ALMA detection
  21. GRB 240825A: SAO RAS optical observations
  22. GRB 240825A: TNG optical photometry and spectroscopy
  23. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  24. GRB 240825A: GMG Continued Optical Observation on the Second Night
  25. GRB 240825A: KAIT optical observations
  26. GRB 240825A: PRIME near-infrared detection
  27. Konus-Wind detection of GRB 240825A (bright/long)
  28. GRB 240825A: Fermi GBM Observation
  29. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  30. GRB 240825A: AKO Optical Follow-Up Observations
  31. GRB 240825A: AstroSat CZTI detection of the long bright burst
  32. GRB 240825A: Swift/UVOT Detection
  33. GRB 240825A: REM detection of the optical/NIR afterglow
  34. GRB 240825A: Swift-XRT refined Analysis
  35. GRB 240825A: VLT/X-shooter redshift
  36. GRB 240825A: SVOM/C-GFT optical observations
  37. GRB 240825A: Montarrenti Observatory optical observations
  38. GRB 240825A: Enhanced Swift-XRT position
  39. GRB 240825A: MASTER optical counterpart observation
  40. GRB 240825A: Fermi-LAT detection
  41. GRB 240825A: LCO optical observations
  42. Fermi GRB 240825A: Global MASTER-Net observations report
  43. GRB 240825A: GMG Optical Observation
  44. Swift GRB 240825A: Global MASTER-Net observations report
  45. GRB 240825A: 1.6m Mephisto multi-band detection
  46. GRB 240825A: AKO Optical Afterglow Detection
  47. GRB 240825A: Skynet Optical Afterglow observations
  48. GRB 240825A: Nanshan/HMT optical afterglow observations
  49. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  50. GRB 240825A: Fermi GBM Final Real-time Localization

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