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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"

35263 results found.

  1. GRB 991105, optical observations
  2. GRB991106, optical observation at SAO-RAS
  3. GRB 991106, LOTIS Optical Observations
  4. GRB 991106, optical observations
  5. BeppoSAX GRB Alert: GRB991106
  6. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  7. GRB ALERT: GRB991105
  8. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  9. GRB 991014, Optical Observations
  10. GRB 991014 - BeppoSAX NFI observations
  11. GRB 991014, Optical Observations
  12. GRB 991014, radio observations
  13. GRB991014 BATSE Observations
  14. GRB 991014, Optical Observations
  15. GRB 991014, optical observations
  16. Super-LOTIS optical observation of GRB991014
  17. IPN/NFI error box for GRB991014
  18. IPN localization of GRB991014 - CORRECTION
  19. IPN localization of GRB991014
  20. BeppoSAX ALERT: GRB991014
  21. GRB 990915 optical observations
  22. GRB 990907 optical observations
  23. BATSE GRB trigger criteria
  24. Optical Observations of GRB990907
  25. IPN error box for GRB990915 (=BATSE 7766)
  26. IPN localization of BATSE #7766 (GRB990915)
  27. IPN localization of GRB990907
  28. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  29. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  30. GRB 990712 Late Optical Decay and Host Galaxy
  31. GRB 990712, Optical Observation
  32. GRB990806: BATSE Observations
  33. GRB 990806 Optical observations
  34. Optical Observations of GRB990806
  35. GRB 990806, Optical Observations
  36. GRB 990806, optical observations
  37. GRB 990806, Optical Observations
  38. GRB990806 UBVRIJHK observations
  39. BeppoSAX ALERT GRB990806: Summer GRB
  40. GRB 990712 Optical Observations
  41. GRB990705: No Evidence for Neutrino Signal
  42. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  43. VLT spectrum of GRB990712
  44. GRB 990712
  45. Late-time HST/STIS Observations of GRB 990510
  46. Refined BeppoSAX-WFC position of GRB990712
  47. GRB 990705, R-band observations
  48. Updated IPN localization of GRB990705
  49. IPN localization of GRB990704
  50. IPN localization of GRB990705
  51. Infrared and Optical Observations of GRB990705
  52. GRB 990705, radio observations
  53. GRB990704 radio and optical observations
  54. GRB 990704 X-ray Observations
  55. GRB 990704 Optical Observations
  56. GRB 990704, optical observations
  57. GRB990704
  58. GRB990705: Intriguing Positional Coincidences
  59. GRB990704
  60. GRB990704, optical observations
  61. Identification of a possible optical counterpart for GRB990704
  62. GRB990704
  63. Refined BeppoSAX-WFC position of GRB990704
  64. GRB990704: BeppoSAX detection
  65. Optical Observations of GRB990627
  66. GRB 990627, radio observations
  67. GRB990627: BeppoSAX-WFC final location
  68. BeppoSAX: GRB990625
  69. Late-time HST/STIS Observation of GRB 990123
  70. GRB 990506 - clarification to GCN 352
  71. GRB 990506 - Optical Observations
  72. Optical Observations of GRB 990506
  73. GRB 990506 Radio Transient
  74. GRB990527 Optical Observations
  75. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  76. IPN error box for GRB990527
  77. Late Afterglows of GRBs 990510, 990123
  78. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  79. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  80. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  81. GRB 990506 optical observation
  82. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  83. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  84. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  85. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  86. radio observations of X-ray/GRB transient field
  87. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  88. Optical report on X-ray/GRB transient
  89. radio detection of X-ray/GRB transient
  90. BeppoSAX: A new fast X-ray transient
  91. GRB 990510: optical observations
  92. GRB990510: photometric and spectroscopic observations with the VLT
  93. GRB 990510: optical linear polarization
  94. GRB 990510: optical observations
  95. GRB990510, VI observations
  96. GRB 990506 R band observations
  97. GRB990510: X-ray afterglow
  98. GRB 990510: optical observation
  99. VLT spectrum of GRB990510
  100. GRB 990510: Broad Band Break

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