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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"

37518 results found.

  1. IPN localization of GRB991226
  2. Single IPN error box for GRB991221
  3. IPN error boxes for GRB991221
  4. GRB 991216 RXTE ASM Observations
  5. IPN error box for GRB991216
  6. GRB 991216: Updated BATSE parameters
  7. Lowell/Perkins observation of GRB 991216
  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 Observations
  12. GRB 991216 Optical spectroscopy/imaging
  13. K observations of GRB991216
  14. GRB 991217 (SAX J2303.2+0015) Optical observations
  15. GRB991216 Spectroscopy
  16. Lowell/Perkins observation of GRB 991216
  17. GRB991216, optical observations
  18. Refined IPN localization of GRB991216
  19. GRB 991216 Radio Observations
  20. GRB 991217
  21. GRB 991208 Keck Spectroscopy
  22. GRB 991208 Infrared Detection
  23. GRB 991216--Summary of RXTE Observations
  24. GRB 991216 Optical Observations
  25. GRB 991216, optical observations
  26. GRB 991208 SAO-RAS Spectroscopy
  27. SAX J2303.2+0015: an x-ray/GRB?
  28. GRB 991216, Optical Transient
  29. GRB 991216, Optical Afterglow
  30. GRB 991216: Comparison with DPOSS images
  31. GRB 991208 optical observations
  32. Lowell/Perkins observation of GRB 991216
  33. GRB 991216 Optical Observation
  34. GRB 991208 Keck Spectroscopy
  35. GRB 991216: Extremely bright BATSE burst
  36. GRB991208, optical observations
  37. GRB 991208 Keck Spectroscopy
  38. GRB991208 - millimeter detection
  39. GRB 991208, Optical Observation
  40. GRB 991208 - OVRO detection
  41. GRB 991208 Optical Decay
  42. GRB 991208 optical observations
  43. GRB 991208 optical observations
  44. GRB 991208: Radio Observations
  45. IPN localization of GRB991208
  46. Optical Observations of GRB991105
  47. GRB991106: BeppoSAX/BATSE results
  48. GRB 991106, optical observations
  49. GRB991106, near-infrared observations
  50. BeppoSAX NFI Observation of GRB991106
  51. GRB 991106, radio observations
  52. GRB991106: the first BeppoSAX short GRB detection?
  53. GRB 991105: BATSE Observations
  54. IPN localization of GRB991105
  55. GRB 991106 Optical Observations
  56. GRB 991105, optical observations
  57. GRB991106, optical observation at SAO-RAS
  58. GRB 991106, LOTIS Optical Observations
  59. GRB 991106, optical observations
  60. BeppoSAX GRB Alert: GRB991106
  61. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  62. GRB ALERT: GRB991105
  63. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  64. GRB 991014, Optical Observations
  65. GRB 991014 - BeppoSAX NFI observations
  66. GRB 991014, Optical Observations
  67. GRB 991014, radio observations
  68. GRB991014 BATSE Observations
  69. GRB 991014, Optical Observations
  70. GRB 991014, optical observations
  71. Super-LOTIS optical observation of GRB991014
  72. IPN/NFI error box for GRB991014
  73. IPN localization of GRB991014 - CORRECTION
  74. IPN localization of GRB991014
  75. BeppoSAX ALERT: GRB991014
  76. GRB 990915 optical observations
  77. GRB 990907 optical observations
  78. BATSE GRB trigger criteria
  79. Optical Observations of GRB990907
  80. IPN error box for GRB990915 (=BATSE 7766)
  81. IPN localization of BATSE #7766 (GRB990915)
  82. IPN localization of GRB990907
  83. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  84. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  85. GRB 990712 Late Optical Decay and Host Galaxy
  86. GRB 990712, Optical Observation
  87. GRB990806: BATSE Observations
  88. GRB 990806 Optical observations
  89. Optical Observations of GRB990806
  90. GRB 990806, Optical Observations
  91. GRB 990806, optical observations
  92. GRB 990806, Optical Observations
  93. GRB990806 UBVRIJHK observations
  94. BeppoSAX ALERT GRB990806: Summer GRB
  95. GRB 990712 Optical Observations
  96. GRB990705: No Evidence for Neutrino Signal
  97. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  98. VLT spectrum of GRB990712
  99. GRB 990712
  100. Late-time HST/STIS Observations of GRB 990510

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