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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').
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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"

45422 results found.

  1. GRB 991014, Optical Observations
  2. GRB 991014, optical observations
  3. Super-LOTIS optical observation of GRB991014
  4. IPN/NFI error box for GRB991014
  5. IPN localization of GRB991014 - CORRECTION
  6. IPN localization of GRB991014
  7. BeppoSAX ALERT: GRB991014
  8. GRB 990915 optical observations
  9. GRB 990907 optical observations
  10. Optical Observations of GRB990907
  11. IPN error box for GRB990915 (=BATSE 7766)
  12. IPN localization of BATSE #7766 (GRB990915)
  13. GRB990907: BeppoSAX follow up and X-ray afterglow
  14. GRB990907 and 990908
  15. IPN localization of GRB990907
  16. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  17. GRB990907: refined WFC position
  18. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  19. GRB 990712 Late Optical Decay and Host Galaxy
  20. GRB 990712, Optical Observation
  21. GRB990806 BeppoSAX follow up
  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. GRB990806: possible X-ray afterglow, BeppoSAX
  30. BeppoSAX ALERT GRB990806: Summer GRB
  31. GRB 990712 Optical Observations
  32. GRB990705: No Evidence for Neutrino Signal
  33. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  34. VLT spectrum of GRB990712
  35. GRB 990712
  36. Late-time HST/STIS Observations of GRB 990510
  37. Refined BeppoSAX-WFC position of GRB990712
  38. BeppoSAX NFI Observation of GRB990705
  39. BeppoSAX NFI Observation of GRB990705
  40. Updated Astrometry for the IR Counterpart of GRB990705
  41. GRB 990705, R-band observations
  42. Updated IPN localization of GRB990705
  43. IPN localization of GRB990704
  44. IPN localization of GRB990705
  45. Infrared and Optical Observations of GRB990705
  46. GRB 990705, radio observations
  47. GRB990704: SAX-NFI results summary
  48. GRB990704 radio and optical observations
  49. BeppoSAX GRB990705: possible X-ray afterglow
  50. GRB 990704 X-ray Observations
  51. GRB 990704 Optical Observations
  52. GRB 990704, optical observations
  53. GRB990704
  54. GRB990705: Intriguing Positional Coincidences
  55. GRB990704
  56. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  57. GRB990704, optical observations
  58. GRB990704: possible X-ray afterglow
  59. Identification of a possible optical counterpart for GRB990704
  60. GRB990704
  61. Refined BeppoSAX-WFC position of GRB990704
  62. GRB990704: BeppoSAX detection
  63. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  64. Optical Observations of GRB990627
  65. GRB 990627, radio observations
  66. GRB990627: BeppoSAX-WFC final location
  67. BeppoSAX: GRB990625
  68. Late-time HST/STIS Observation of GRB 990123
  69. GRB 990506 - clarification to GCN 352
  70. GRB 990506 - Optical Observations
  71. Optical Observations of GRB 990506
  72. GRB 990506 Radio Transient
  73. GRB990527 Optical Observations
  74. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  75. IPN error box for GRB990527
  76. Late Afterglows of GRBs 990510, 990123
  77. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  78. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  79. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  80. GRB 990506 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. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  85. radio observations of X-ray/GRB transient field
  86. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  87. Optical report on X-ray/GRB transient
  88. radio detection of X-ray/GRB transient
  89. BeppoSAX: A new fast X-ray transient
  90. GRB 990510: optical observations
  91. GRB990510: photometric and spectroscopic observations with the VLT
  92. GRB 990510: optical linear polarization
  93. GRB 990510: optical observations
  94. GRB990510, VI observations
  95. GRB 990506 R band observations
  96. GRB990510: X-ray afterglow
  97. GRB 990510: optical observation
  98. VLT spectrum of GRB990510
  99. GRB 990510: Broad Band Break
  100. GRB 990510: BATSE Observations

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