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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"

43604 results found.

  1. GRB 991014, Optical Observations
  2. GRB 991014, optical observations
  3. Super-LOTIS optical observation of GRB991014
  4. IPN localization of GRB991014 - CORRECTION
  5. IPN localization of GRB991014
  6. BeppoSAX ALERT: GRB991014
  7. GRB 990915 optical observations
  8. GRB 990907 optical observations
  9. Optical Observations of GRB990907
  10. IPN error box for GRB990915 (=BATSE 7766)
  11. IPN localization of BATSE #7766 (GRB990915)
  12. GRB990907: BeppoSAX follow up and X-ray afterglow
  13. GRB990907 and 990908
  14. IPN localization of GRB990907
  15. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  16. GRB990907: refined WFC position
  17. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  18. GRB 990712 Late Optical Decay and Host Galaxy
  19. GRB 990712, Optical Observation
  20. GRB990806 BeppoSAX follow up
  21. GRB990806: BATSE Observations
  22. GRB 990806 Optical observations
  23. Optical Observations of GRB990806
  24. GRB 990806, Optical Observations
  25. GRB 990806, optical observations
  26. GRB 990806, Optical Observations
  27. GRB990806 UBVRIJHK observations
  28. GRB990806: possible X-ray afterglow, BeppoSAX
  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. BeppoSAX NFI Observation of GRB990705
  38. BeppoSAX NFI Observation of GRB990705
  39. GRB 990705, R-band observations
  40. Updated IPN localization of GRB990705
  41. IPN localization of GRB990704
  42. IPN localization of GRB990705
  43. Infrared and Optical Observations of GRB990705
  44. GRB 990705, radio observations
  45. GRB990704: SAX-NFI results summary
  46. BeppoSAX GRB990705: possible X-ray afterglow
  47. GRB 990704 X-ray Observations
  48. GRB 990704 Optical Observations
  49. GRB 990704, optical observations
  50. GRB990704
  51. GRB990705: Intriguing Positional Coincidences
  52. GRB990704
  53. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  54. GRB990704, optical observations
  55. GRB990704: possible X-ray afterglow
  56. Identification of a possible optical counterpart for GRB990704
  57. GRB990704
  58. Refined BeppoSAX-WFC position of GRB990704
  59. GRB990704: BeppoSAX detection
  60. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  61. Optical Observations of GRB990627
  62. GRB 990627, radio observations
  63. GRB990627: BeppoSAX-WFC final location
  64. BeppoSAX: GRB990625
  65. Late-time HST/STIS Observation of GRB 990123
  66. GRB 990506 - clarification to GCN 352
  67. GRB 990506 - Optical Observations
  68. Optical Observations of GRB 990506
  69. GRB 990506 Radio Transient
  70. GRB990527 Optical Observations
  71. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  72. IPN error box for GRB990527
  73. Late Afterglows of GRBs 990510, 990123
  74. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  75. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  76. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  77. GRB 990506 optical observation
  78. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  79. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  80. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  81. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  82. radio observations of X-ray/GRB transient field
  83. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  84. Optical report on X-ray/GRB transient
  85. radio detection of X-ray/GRB transient
  86. BeppoSAX: A new fast X-ray transient
  87. GRB 990510: optical observations
  88. GRB990510: photometric and spectroscopic observations with the VLT
  89. GRB 990510: optical linear polarization
  90. GRB 990510: optical observations
  91. GRB990510, VI observations
  92. GRB 990506 R band observations
  93. GRB990510: X-ray afterglow
  94. GRB 990510: optical observation
  95. VLT spectrum of GRB990510
  96. GRB 990510: Broad Band Break
  97. GRB 990510: BATSE Observations
  98. GRB 990510 Optical Observations
  99. GRB 990510, BVI photometry
  100. GRB 990510 optical observations

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