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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"

32509 results found.

  1. Revised BeppoSAX WFC position of GRB991105
  2. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  3. GRB 991014, Optical Observations
  4. GRB 991014 - BeppoSAX NFI observations
  5. GRB 991014, Optical Observations
  6. GRB 991014, Optical Observations
  7. GRB 991014, optical observations
  8. Super-LOTIS optical observation of GRB991014
  9. IPN/NFI error box for GRB991014
  10. IPN localization of GRB991014 - CORRECTION
  11. IPN localization of GRB991014
  12. GRB 990915 optical observations
  13. GRB 990907 optical observations
  14. Optical Observations of GRB990907
  15. IPN error box for GRB990915 (=BATSE 7766)
  16. IPN localization of BATSE #7766 (GRB990915)
  17. GRB990907: BeppoSAX follow up and X-ray afterglow
  18. GRB990907 and 990908
  19. IPN localization of GRB990907
  20. GRB 990712 Late Optical Decay and Host Galaxy
  21. GRB 990712, Optical Observation
  22. GRB990806 BeppoSAX follow up
  23. GRB990806: BATSE Observations
  24. GRB 990806 Optical observations
  25. Optical Observations of GRB990806
  26. GRB 990806, Optical Observations
  27. GRB 990806, optical observations
  28. GRB 990806, Optical Observations
  29. GRB990806 UBVRIJHK observations
  30. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  31. VLT spectrum of GRB990712
  32. GRB 990712
  33. Late-time HST/STIS Observations of GRB 990510
  34. BeppoSAX NFI Observation of GRB990705
  35. BeppoSAX NFI Observation of GRB990705
  36. Updated Astrometry for the IR Counterpart of GRB990705
  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: SAX-NFI results summary
  44. GRB990704 radio and optical observations
  45. GRB 990704 X-ray Observations
  46. GRB 990704 Optical Observations
  47. GRB 990704, optical observations
  48. GRB990704
  49. GRB990704
  50. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  51. GRB990704, optical observations
  52. GRB990704: possible X-ray afterglow
  53. Identification of a possible optical counterpart for GRB990704
  54. GRB990704
  55. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  56. Optical Observations of GRB990627
  57. GRB 990627, radio observations
  58. GRB990627: BeppoSAX-WFC final location
  59. GRB 990506 - clarification to GCN 352
  60. GRB 990506 - Optical Observations
  61. Optical Observations of GRB 990506
  62. GRB 990506 Radio Transient
  63. GRB990527 Optical Observations
  64. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  65. Late Afterglows of GRBs 990510, 990123
  66. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  67. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  68. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  69. GRB 990506 optical observation
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  71. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  72. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. radio observations of X-ray/GRB transient field
  75. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  76. Optical report on X-ray/GRB transient
  77. radio detection of X-ray/GRB transient
  78. BeppoSAX: A new fast X-ray transient
  79. GRB 990510: optical observations
  80. GRB990510, VI observations
  81. GRB 990506 R band observations
  82. GRB990510: X-ray afterglow
  83. VLT spectrum of GRB990510
  84. GRB 990510: Broad Band Break
  85. GRB 990510: BATSE Observations
  86. GRB990510: optical observation
  87. GRB 990510 Optical Observations
  88. GRB 990510, BVI photometry
  89. GRB 990510 optical observations
  90. GRB990510 optical observations
  91. GRB990510
  92. GRB 990510 optical observations
  93. GRB 990510 optical observations
  94. Galactic extinction towards GRB 990510
  95. IPN localization of GRB990510
  96. GRB 990506 Radio Observations
  97. GRB 990506: BATSE Observations
  98. GRB 990506, optical observations
  99. GRB 990506, Optical Observations
  100. GRB 990506 optical observations

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