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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"

38264 results found.

  1. BeppoSAX GRB Alert: GRB991106
  2. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  3. GRB ALERT: GRB991105
  4. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  5. GRB 991014, Optical Observations
  6. GRB 991014 - BeppoSAX NFI observations
  7. GRB 991014, Optical Observations
  8. GRB 991014, radio observations
  9. GRB991014 BATSE Observations
  10. GRB 991014, Optical Observations
  11. GRB 991014, optical observations
  12. Super-LOTIS optical observation of GRB991014
  13. IPN/NFI error box for GRB991014
  14. IPN localization of GRB991014 - CORRECTION
  15. IPN localization of GRB991014
  16. BeppoSAX ALERT: GRB991014
  17. GRB 990915 optical observations
  18. GRB 990907 optical observations
  19. BATSE GRB trigger criteria
  20. Optical Observations of GRB990907
  21. IPN error box for GRB990915 (=BATSE 7766)
  22. IPN localization of BATSE #7766 (GRB990915)
  23. IPN localization of GRB990907
  24. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  25. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  26. GRB 990712 Late Optical Decay and Host Galaxy
  27. GRB 990712, Optical Observation
  28. GRB990806 BeppoSAX follow up
  29. GRB990806: BATSE Observations
  30. GRB 990806 Optical observations
  31. Optical Observations of GRB990806
  32. GRB 990806, Optical Observations
  33. GRB 990806, optical observations
  34. GRB 990806, Optical Observations
  35. GRB990806 UBVRIJHK observations
  36. BeppoSAX ALERT GRB990806: Summer GRB
  37. GRB 990712 Optical Observations
  38. GRB990705: No Evidence for Neutrino Signal
  39. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  40. VLT spectrum of GRB990712
  41. GRB 990712
  42. Late-time HST/STIS Observations of GRB 990510
  43. Refined BeppoSAX-WFC position of GRB990712
  44. GRB 990705, R-band observations
  45. Updated IPN localization of GRB990705
  46. IPN localization of GRB990704
  47. IPN localization of GRB990705
  48. Infrared and Optical Observations of GRB990705
  49. GRB 990705, radio observations
  50. GRB990704 radio and optical observations
  51. BeppoSAX GRB990705: possible X-ray afterglow
  52. GRB 990704 X-ray Observations
  53. GRB 990704 Optical Observations
  54. GRB 990704, optical observations
  55. GRB990704
  56. GRB990705: Intriguing Positional Coincidences
  57. GRB990704
  58. GRB990704, optical observations
  59. Identification of a possible optical counterpart for GRB990704
  60. GRB990704
  61. Refined BeppoSAX-WFC position of GRB990704
  62. GRB990704: BeppoSAX detection
  63. Optical Observations of GRB990627
  64. GRB 990627, radio observations
  65. GRB990627: BeppoSAX-WFC final location
  66. BeppoSAX: GRB990625
  67. Late-time HST/STIS Observation of GRB 990123
  68. GRB 990506 - clarification to GCN 352
  69. GRB 990506 - Optical Observations
  70. Optical Observations of GRB 990506
  71. GRB 990506 Radio Transient
  72. GRB990527 Optical Observations
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. IPN error box for GRB990527
  75. Late Afterglows of GRBs 990510, 990123
  76. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  77. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  78. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  79. GRB 990506 optical observation
  80. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  81. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  82. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  83. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  84. radio observations of X-ray/GRB transient field
  85. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  86. Optical report on X-ray/GRB transient
  87. radio detection of X-ray/GRB transient
  88. BeppoSAX: A new fast X-ray transient
  89. GRB 990510: optical observations
  90. GRB990510: photometric and spectroscopic observations with the VLT
  91. GRB 990510: optical linear polarization
  92. GRB 990510: optical observations
  93. GRB990510, VI observations
  94. GRB 990506 R band observations
  95. GRB990510: X-ray afterglow
  96. GRB 990510: optical observation
  97. VLT spectrum of GRB990510
  98. GRB 990510: Broad Band Break
  99. GRB 990510: BATSE Observations
  100. GRB 990510 Optical Observations

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