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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"

24873 results found.

  1. GCN resumes full operations
  2. GRB 991216 VLBA Observations
  3. GRB 991216: J band spectrophotometry
  4. GRB 991216: Detection of the Host and/or Absorber Galaxy
  5. IPN localization of GRB991226
  6. GRB 991216 RXTE ASM Observations
  7. GRB 991216: Updated BATSE parameters
  8. GRB 991217 (SAX J2303.2+0015) Optical observations
  9. Chandra observation of the X-ray afterglow of GRB991216
  10. GRB 991216, optical observations
  11. GRB 991216 Optical spectroscopy/imaging
  12. SAX J2303.2+0015 Optical observations
  13. IR observations of GRB991216
  14. GRB 991217 (SAX J2303.2+0015) Optical observations
  15. GRB991216 Optical and infrared observations of Beethoven Burst
  16. GRB 991216 Radio Observations
  17. GRB 991208 Keck Spectroscopy
  18. GRB 991208 Infrared Detection
  19. GRB991216
  20. GRB 991216--Summary of RXTE Observations
  21. GRB 991216 Optical Observations
  22. GRB 991216, optical observations
  23. GRB 991208 SAO-RAS Spectroscopy
  24. SAX J2303.2+0015: an x-ray/GRB?
  25. GRB 991216, Optical Transient
  26. GRB991216 ('Beethoven Burst') B, R, and K Observations
  27. GRB991216, infrared observations
  28. GRB 991208 optical observations
  29. GRB 991216 Optical Observation
  30. GRB 991216: Extremely bright BATSE burst
  31. R-band Observations of GRB991208 at TNG
  32. GRB991208, optical observations
  33. GRB 991208, Optical Observation
  34. GRB991208, optical observations
  35. GRB 991208 optical observations
  36. Optical Observations of GRB991105
  37. GRB991106: BeppoSAX/BATSE results
  38. GRB991106, near-infrared observations
  39. BeppoSAX NFI Observation of GRB991106
  40. GRB 991106, radio observations
  41. GRB991106: the first BeppoSAX short GRB detection?
  42. GRB 991105: BATSE Observations
  43. GRB 991106 Optical Observations
  44. GRB991106, optical observation at SAO-RAS
  45. GRB 991106, LOTIS Optical Observations
  46. GRB991105: SAX-GRBM/-WFC detection
  47. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  48. GRB 991014, Optical Observations
  49. GRB 991014 - BeppoSAX NFI observations
  50. GRB 991014, radio observations
  51. GRB 991014, Optical Observations
  52. GRB 991014, optical observations
  53. GRB 990915 optical observations
  54. Optical Observations of GRB990907
  55. GRB990907: BeppoSAX follow up and X-ray afterglow
  56. GRB990907 and 990908
  57. GRB 990712 Late Optical Decay and Host Galaxy
  58. GRB990806 BeppoSAX follow up
  59. GRB990806: BATSE Observations
  60. GRB 990806 Optical observations
  61. GRB 990806, Optical Observations
  62. GRB 990806, optical observations
  63. GRB 990806, Optical Observations
  64. GRB990806 UBVRIJHK observations
  65. GRB 990712 Optical Observations
  66. GRB 990712
  67. Late-time HST/STIS Observations of GRB 990510
  68. BeppoSAX NFI Observation of GRB990705
  69. BeppoSAX NFI Observation of GRB990705
  70. GRB 990705, R-band observations
  71. Infrared and Optical Observations of GRB990705
  72. GRB990704: SAX-NFI results summary
  73. GRB990704 radio and optical observations
  74. GRB990704
  75. GRB990704, optical observations
  76. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  77. Optical Observations of GRB990627
  78. BeppoSAX: GRB990625
  79. Late-time HST/STIS Observation of GRB 990123
  80. Optical Observations of GRB 990506
  81. GRB990527 Optical Observations
  82. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  83. Late Afterglows of GRBs 990510, 990123
  84. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  85. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  86. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  87. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  88. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  89. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  90. radio observations of X-ray/GRB transient field
  91. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  92. Optical report on X-ray/GRB transient
  93. radio detection of X-ray/GRB transient
  94. BeppoSAX: A new fast X-ray transient
  95. GRB 990510: optical observations
  96. GRB 990510: optical linear polarization
  97. GRB 990510: optical observations
  98. GRB990510: X-ray afterglow
  99. GRB 990510: Broad Band Break
  100. GRB 990510: BATSE Observations

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