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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"

41698 results found.

  1. GRB 991106, optical observations
  2. Revised BeppoSAX WFC position of GRB991105
  3. GRB991105: SAX-GRBM/-WFC detection
  4. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  5. GRB 991014, Optical Observations
  6. GRB 991014 - BeppoSAX NFI observations
  7. GRB 991014, Optical Observations
  8. GRB991014 BATSE Observations
  9. GRB 991014, Optical Observations
  10. GRB 991014, optical observations
  11. Super-LOTIS optical observation of GRB991014
  12. IPN/NFI error box for GRB991014
  13. IPN localization of GRB991014 - CORRECTION
  14. IPN localization of GRB991014
  15. GRB 990915 optical observations
  16. GRB 990907 optical observations
  17. Optical Observations of GRB990907
  18. IPN error box for GRB990915 (=BATSE 7766)
  19. IPN localization of BATSE #7766 (GRB990915)
  20. GRB990907: BeppoSAX follow up and X-ray afterglow
  21. GRB990907 and 990908
  22. IPN localization of GRB990907
  23. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  24. GRB 990712 Late Optical Decay and Host Galaxy
  25. GRB 990712, Optical Observation
  26. GRB990806 BeppoSAX follow up
  27. GRB990806: BATSE Observations
  28. GRB 990806 Optical observations
  29. Optical Observations of GRB990806
  30. GRB 990806, Optical Observations
  31. GRB 990806, optical observations
  32. GRB 990806, Optical Observations
  33. GRB990806 UBVRIJHK observations
  34. GRB 990712 Optical Observations
  35. GRB990705: No Evidence for Neutrino Signal
  36. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  37. VLT spectrum of GRB990712
  38. GRB 990712
  39. Late-time HST/STIS Observations of GRB 990510
  40. BeppoSAX NFI Observation of GRB990705
  41. BeppoSAX NFI Observation of GRB990705
  42. Updated Astrometry for the IR Counterpart of GRB990705
  43. GRB 990705, R-band observations
  44. Updated IPN localization of GRB990705
  45. IPN localization of GRB990704
  46. IPN localization of GRB990705
  47. Infrared and Optical Observations of GRB990705
  48. GRB 990705, radio observations
  49. GRB990704: SAX-NFI results summary
  50. GRB990704 radio and optical observations
  51. GRB 990704 X-ray Observations
  52. GRB 990704 Optical Observations
  53. GRB 990704, optical observations
  54. GRB990704
  55. GRB990705: Intriguing Positional Coincidences
  56. GRB990704
  57. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  58. GRB990704, optical observations
  59. GRB990704: possible X-ray afterglow
  60. Identification of a possible optical counterpart for GRB990704
  61. GRB990704
  62. Refined BeppoSAX-WFC position of GRB990704
  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. Late-time HST/STIS Observation of GRB 990123
  68. GRB 990506 - clarification to GCN 352
  69. GRB 990506 - Optical Observations
  70. Optical Observations of GRB 990506
  71. GRB 990506 Radio Transient
  72. GRB990527 Optical Observations
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. Late Afterglows of GRBs 990510, 990123
  75. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  76. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  77. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  78. GRB 990506 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. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  83. radio observations of X-ray/GRB transient field
  84. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  85. Optical report on X-ray/GRB transient
  86. radio detection of X-ray/GRB transient
  87. BeppoSAX: A new fast X-ray transient
  88. GRB 990510: optical linear polarization
  89. GRB 990510: optical observations
  90. GRB990510, VI observations
  91. GRB 990506 R band observations
  92. GRB990510: X-ray afterglow
  93. GRB 990510: optical observation
  94. VLT spectrum of GRB990510
  95. GRB 990510: Broad Band Break
  96. GRB 990510: BATSE Observations
  97. GRB990510: optical observation
  98. GRB 990510 Optical Observations
  99. GRB 990510, BVI photometry
  100. GRB 990510 optical observations

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