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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"

37512 results found.

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

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