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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"

37513 results found.

  1. GRB 991216: Updated BATSE parameters
  2. Lowell/Perkins observation of GRB 991216
  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 Observations
  7. GRB 991216 Optical spectroscopy/imaging
  8. K observations of GRB991216
  9. GRB 991217 (SAX J2303.2+0015) Optical observations
  10. GRB991216 Spectroscopy
  11. Lowell/Perkins observation of GRB 991216
  12. GRB991216, optical observations
  13. Refined IPN localization of GRB991216
  14. GRB 991216 Radio Observations
  15. GRB 991217
  16. GRB 991208 Keck Spectroscopy
  17. GRB 991208 Infrared Detection
  18. GRB 991216--Summary of RXTE Observations
  19. GRB 991216 Optical Observations
  20. GRB 991216, optical observations
  21. GRB 991208 SAO-RAS Spectroscopy
  22. SAX J2303.2+0015: an x-ray/GRB?
  23. GRB 991216, Optical Transient
  24. GRB 991216, Optical Afterglow
  25. GRB 991216: Comparison with DPOSS images
  26. GRB 991208 optical observations
  27. Lowell/Perkins observation of GRB 991216
  28. GRB 991216 Optical Observation
  29. GRB 991208 Keck Spectroscopy
  30. GRB 991216: Extremely bright BATSE burst
  31. GRB991208, optical observations
  32. GRB 991208 Keck Spectroscopy
  33. GRB991208 - millimeter detection
  34. GRB 991208, Optical Observation
  35. GRB 991208 - OVRO detection
  36. GRB 991208 Optical Decay
  37. GRB 991208 optical observations
  38. GRB 991208 optical observations
  39. GRB 991208: Radio Observations
  40. IPN localization of GRB991208
  41. Optical Observations of GRB991105
  42. GRB991106: BeppoSAX/BATSE results
  43. GRB 991106, optical observations
  44. GRB991106, near-infrared observations
  45. BeppoSAX NFI Observation of GRB991106
  46. GRB 991106, radio observations
  47. GRB991106: the first BeppoSAX short GRB detection?
  48. GRB 991105: BATSE Observations
  49. IPN localization of GRB991105
  50. GRB 991106 Optical Observations
  51. GRB 991105, optical observations
  52. GRB991106, optical observation at SAO-RAS
  53. GRB 991106, LOTIS Optical Observations
  54. GRB 991106, optical observations
  55. BeppoSAX GRB Alert: GRB991106
  56. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  57. GRB ALERT: GRB991105
  58. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  59. GRB 991014, Optical Observations
  60. GRB 991014 - BeppoSAX NFI observations
  61. GRB 991014, Optical Observations
  62. GRB 991014, radio observations
  63. GRB991014 BATSE Observations
  64. GRB 991014, Optical Observations
  65. GRB 991014, optical observations
  66. Super-LOTIS optical observation of GRB991014
  67. IPN/NFI error box for GRB991014
  68. IPN localization of GRB991014 - CORRECTION
  69. IPN localization of GRB991014
  70. BeppoSAX ALERT: GRB991014
  71. GRB 990915 optical observations
  72. GRB 990907 optical observations
  73. BATSE GRB trigger criteria
  74. Optical Observations of GRB990907
  75. IPN error box for GRB990915 (=BATSE 7766)
  76. IPN localization of BATSE #7766 (GRB990915)
  77. IPN localization of GRB990907
  78. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  79. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  80. GRB 990712 Late Optical Decay and Host Galaxy
  81. GRB 990712, Optical Observation
  82. GRB990806: BATSE Observations
  83. GRB 990806 Optical observations
  84. Optical Observations of GRB990806
  85. GRB 990806, Optical Observations
  86. GRB 990806, optical observations
  87. GRB 990806, Optical Observations
  88. GRB990806 UBVRIJHK observations
  89. BeppoSAX ALERT GRB990806: Summer GRB
  90. GRB 990712 Optical Observations
  91. GRB990705: No Evidence for Neutrino Signal
  92. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  93. VLT spectrum of GRB990712
  94. GRB 990712
  95. Late-time HST/STIS Observations of GRB 990510
  96. Refined BeppoSAX-WFC position of GRB990712
  97. GRB 990705, R-band observations
  98. Updated IPN localization of GRB990705
  99. IPN localization of GRB990704
  100. IPN localization of GRB990705

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