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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"

3360 results found.

  1. GCN and HETE status
  2. BeppoSAX/GRBM detection of GRB010728
  3. SGR1900+14: Second Burst Localized by HETE
  4. IPN triangulation of GRB010613
  5. GRB000418: HST/STIS Second-epoch Observations
  6. X-ray precursors to the large flare from SGR 1900+14
  7. SGR 1900+14 : RXTE observations
  8. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  9. GRB010412: BeppoSAX GRBM and WFC observations
  10. GRB010222: Chandra X-ray Observatory Observation
  11. GRB010222 - Optical observation
  12. GRB010222: Optical observation and decay
  13. GRB 010222 HST/Chandra TOO
  14. GRB010222: Optical Observations
  15. GRB 010220, simultaneous optical observations
  16. GRB010126 optical observations
  17. GRB001007, Radio observations
  18. GRB000926 - Amateur Optical Observations
  19. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  20. IPN localization of GRB000801
  21. GRB 990510: Possible detection of a host galaxy
  22. GRB 990510 Host Galaxy Discovery
  23. possible optical counterpart of GRB 000630
  24. IPN annulus for GRB000620
  25. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  26. The redshift of GRB 000418
  27. Correction to IPN error box for GRB000419
  28. GRB 000408, optical observations
  29. GRB000315 [IPN Positions]
  30. GRB000226 [IPN Position]
  31. IPN error boxes for GRB991229
  32. GRB 991106, LOTIS Optical Observations
  33. GRB991105: SAX-GRBM/-WFC detection
  34. GRB 991014, radio observations
  35. GRB 991014, Optical Observations
  36. IPN/NFI error box for GRB991014
  37. GRB990907: BeppoSAX follow up and X-ray afterglow
  38. GRB990806: BATSE Observations
  39. BeppoSAX ALERT GRB990806: Summer GRB
  40. Late-time HST/STIS Observations of GRB 990510
  41. GRB 990510: BeppoSAX/GRBM observations
  42. GRB980425 Optical observations of exponential decline at late time
  43. GRB990321 REFINED IPN ANNULUS
  44. GRB990308, Possible new SGR~0209+70
  45. GRB 990123: New Constraints on Possible Foreground Galaxies
  46. GRB 990123: Continued Radio Observations
  47. GRB 981226: radio variable
  48. GRB 980613: Spectroscopy of the host galaxy
  49. GRB981226 Optical Observations
  50. GRB 981226 optical observations
  51. GRB980613 Optical Observations
  52. GRB 980613 Near-IR observations
  53. GRB 980613: Optical transient and its host galaxy
  54. GRB 980613 optical observations
  55. GRB 980519
  56. GRB980425: Radio Observations
  57. GRB980326 optical observations
  58. Optical Observations of GRB 970508
  59. GRB 971214: Redshift from Keck Observations
  60. GRB 970828: Palomar Observations

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