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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"

41 results found.

  1. GRB 241030A: J-band observations
  2. GRB 241030A: LCO optical observation
  3. GRB 241030A: TESS observations
  4. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  5. GRB 241030A: Mondy optical observations
  6. GRB 241030A: GRBAlpha detection
  7. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  8. GRB 241030A: Rapid release of TESS data.
  9. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  10. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  11. GRB 241030A: further SAO RAS optical observations
  12. GRB 241030A: Optical Observations via Virtual Telescope Project
  13. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  14. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  15. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  16. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  17. GRB 241030A: SAO RAS optical observations
  18. GRB 241030A: Fermi GBM Observation
  19. GRB 241030A: Swift-BAT refined analysis
  20. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  21. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  22. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  23. GRB 241030A: Swift-XRT refined Analysis
  24. Konus-Wind detection of GRB 241030A
  25. GRB 241030A: Fermi-LAT detection
  26. Fermi GRB 241030A: Global MASTER-Net observations report
  27. GRB 241030A: AKO Optical Afterglow Detection
  28. Swift GRB 241030A: Global MASTER-Net observations report
  29. GRB 241030A: Swift/UVOT Detection
  30. GRB 241030A: SVOM/GRM observation
  31. GRB 241030A: SVOM/C-GFT optical observations
  32. GRB 241030A: Multiband optical detection with Mephisto
  33. GRB 241030A: SVOM/VT optical afterglow observations
  34. GRB 241030A : MITSuME Akeno optical afterglow detection
  35. GRB 241030A: Enhanced Swift-XRT position
  36. GRB 241030A: TRT optical observations
  37. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  38. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  39. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  40. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  41. GRB 241030A: Fermi GBM Final Real-time Localization

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