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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"

35426 results found.

  1. Single IPN error box for GRB991229
  2. GCN resumes full operations
  3. GRB 991216 VLBA Observations
  4. BEPPOSAX GRBM Localization of GRB991226
  5. IPN error boxes for GRB991229
  6. GRB 991216: J band spectrophotometry
  7. GRB 991216: Detection of the Host and/or Absorber Galaxy
  8. IPN localization of GRB991226
  9. Single IPN error box for GRB991221
  10. IPN error boxes for GRB991221
  11. GRB 991216 RXTE ASM Observations
  12. IPN error box for GRB991216
  13. GRB 991216: Updated BATSE parameters
  14. Lowell/Perkins observation of GRB 991216
  15. GRB 991217 (SAX J2303.2+0015) Optical observations
  16. Chandra observation of the X-ray afterglow of GRB991216
  17. GRB 991216, optical observations
  18. GRB 991216 Optical Observations
  19. GRB 991216 Optical spectroscopy/imaging
  20. K observations of GRB991216
  21. GRB 991217 (SAX J2303.2+0015) Optical observations
  22. GRB991216 Spectroscopy
  23. Lowell/Perkins observation of GRB 991216
  24. GRB991216, optical observations
  25. Refined IPN localization of GRB991216
  26. GRB 991216 Radio Observations
  27. GRB 991217
  28. GRB 991208 Keck Spectroscopy
  29. GRB 991208 Infrared Detection
  30. GRB 991216--Summary of RXTE Observations
  31. GRB 991216 Optical Observations
  32. GRB 991216, optical observations
  33. GRB 991208 SAO-RAS Spectroscopy
  34. SAX J2303.2+0015: an x-ray/GRB?
  35. GRB 991216, Optical Transient
  36. GRB 991216, Optical Afterglow
  37. GRB 991216: Comparison with DPOSS images
  38. GRB 991208 optical observations
  39. Lowell/Perkins observation of GRB 991216
  40. GRB 991216 Optical Observation
  41. GRB 991208 Keck Spectroscopy
  42. GRB 991216: Extremely bright BATSE burst
  43. GRB991208, optical observations
  44. GRB 991208 Keck Spectroscopy
  45. GRB991208 - millimeter detection
  46. GRB 991208, Optical Observation
  47. GRB 991208 - OVRO detection
  48. GRB 991208 Optical Decay
  49. GRB 991208 optical observations
  50. GRB 991208 optical observations
  51. GRB 991208: Radio Observations
  52. IPN localization of GRB991208
  53. Optical Observations of GRB991105
  54. GRB991106: BeppoSAX/BATSE results
  55. GRB 991106, optical observations
  56. GRB991106, near-infrared observations
  57. BeppoSAX NFI Observation of GRB991106
  58. GRB 991106, radio observations
  59. GRB991106: the first BeppoSAX short GRB detection?
  60. GRB 991105: BATSE Observations
  61. IPN localization of GRB991105
  62. GRB 991106 Optical Observations
  63. GRB 991105, optical observations
  64. GRB991106, optical observation at SAO-RAS
  65. GRB 991106, LOTIS Optical Observations
  66. GRB 991106, optical observations
  67. BeppoSAX GRB Alert: GRB991106
  68. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  69. GRB ALERT: GRB991105
  70. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  71. GRB 991014, Optical Observations
  72. GRB 991014 - BeppoSAX NFI observations
  73. GRB 991014, Optical Observations
  74. GRB 991014, radio observations
  75. GRB991014 BATSE Observations
  76. GRB 991014, Optical Observations
  77. GRB 991014, optical observations
  78. Super-LOTIS optical observation of GRB991014
  79. IPN/NFI error box for GRB991014
  80. IPN localization of GRB991014 - CORRECTION
  81. IPN localization of GRB991014
  82. BeppoSAX ALERT: GRB991014
  83. GRB 990915 optical observations
  84. GRB 990907 optical observations
  85. BATSE GRB trigger criteria
  86. Optical Observations of GRB990907
  87. IPN error box for GRB990915 (=BATSE 7766)
  88. IPN localization of BATSE #7766 (GRB990915)
  89. IPN localization of GRB990907
  90. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  91. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  92. GRB 990712 Late Optical Decay and Host Galaxy
  93. GRB 990712, Optical Observation
  94. GRB990806: BATSE Observations
  95. GRB 990806 Optical observations
  96. Optical Observations of GRB990806
  97. GRB 990806, Optical Observations
  98. GRB 990806, optical observations
  99. GRB 990806, Optical Observations
  100. GRB990806 UBVRIJHK observations

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