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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"

26168 results found.

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

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