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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"

35253 results found.

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

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