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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"

36139 results found.

  1. GRB000126 Optical Observations
  2. BATSE GRB trigger criteria changed
  3. GRB 991208, radio observations
  4. BATSE+IPN location of GRB000131
  5. IPN localization of GRB000131
  6. GRB 000126, optical observations
  7. GRB000126, optical observations
  8. BATSE location of GRB000126
  9. IPN localization of GRB000126
  10. GRB 000115 Optical observations
  11. BATSE Observations of GRB000115
  12. Second RXTE Observation of GRB 000115
  13. GRB991216, UBVRIJHK field photometry
  14. Single IPN error box for GRB991229
  15. GCN resumes full operations
  16. GRB 991216 VLBA Observations
  17. BEPPOSAX GRBM Localization of GRB991226
  18. IPN error boxes for GRB991229
  19. GRB 991216: J band spectrophotometry
  20. GRB 991216: Detection of the Host and/or Absorber Galaxy
  21. IPN localization of GRB991226
  22. Single IPN error box for GRB991221
  23. IPN error boxes for GRB991221
  24. GRB 991216 RXTE ASM Observations
  25. IPN error box for GRB991216
  26. GRB 991216: Updated BATSE parameters
  27. Lowell/Perkins observation of GRB 991216
  28. GRB 991217 (SAX J2303.2+0015) Optical observations
  29. Chandra observation of the X-ray afterglow of GRB991216
  30. GRB 991216, optical observations
  31. GRB 991216 Optical Observations
  32. GRB 991216 Optical spectroscopy/imaging
  33. K observations of GRB991216
  34. GRB 991217 (SAX J2303.2+0015) Optical observations
  35. GRB991216 Spectroscopy
  36. Lowell/Perkins observation of GRB 991216
  37. GRB991216, optical observations
  38. Refined IPN localization of GRB991216
  39. GRB 991216 Radio Observations
  40. GRB 991217
  41. GRB 991208 Keck Spectroscopy
  42. GRB 991208 Infrared Detection
  43. GRB 991216--Summary of RXTE Observations
  44. GRB 991216 Optical Observations
  45. GRB 991216, optical observations
  46. GRB 991208 SAO-RAS Spectroscopy
  47. SAX J2303.2+0015: an x-ray/GRB?
  48. GRB 991216, Optical Transient
  49. GRB 991216, Optical Afterglow
  50. GRB 991216: Comparison with DPOSS images
  51. GRB 991208 optical observations
  52. Lowell/Perkins observation of GRB 991216
  53. GRB 991216 Optical Observation
  54. GRB 991208 Keck Spectroscopy
  55. GRB 991216: Extremely bright BATSE burst
  56. GRB991208, optical observations
  57. GRB 991208 Keck Spectroscopy
  58. GRB991208 - millimeter detection
  59. GRB 991208, Optical Observation
  60. GRB 991208 - OVRO detection
  61. GRB 991208 Optical Decay
  62. GRB 991208 optical observations
  63. GRB 991208 optical observations
  64. GRB 991208: Radio Observations
  65. IPN localization of GRB991208
  66. Optical Observations of GRB991105
  67. GRB991106: BeppoSAX/BATSE results
  68. GRB 991106, optical observations
  69. GRB991106, near-infrared observations
  70. BeppoSAX NFI Observation of GRB991106
  71. GRB 991106, radio observations
  72. GRB991106: the first BeppoSAX short GRB detection?
  73. GRB 991105: BATSE Observations
  74. IPN localization of GRB991105
  75. GRB 991106 Optical Observations
  76. GRB 991105, optical observations
  77. GRB991106, optical observation at SAO-RAS
  78. GRB 991106, LOTIS Optical Observations
  79. GRB 991106, optical observations
  80. BeppoSAX GRB Alert: GRB991106
  81. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  82. GRB ALERT: GRB991105
  83. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  84. GRB 991014, Optical Observations
  85. GRB 991014 - BeppoSAX NFI observations
  86. GRB 991014, Optical Observations
  87. GRB 991014, radio observations
  88. GRB991014 BATSE Observations
  89. GRB 991014, Optical Observations
  90. GRB 991014, optical observations
  91. Super-LOTIS optical observation of GRB991014
  92. IPN/NFI error box for GRB991014
  93. IPN localization of GRB991014 - CORRECTION
  94. IPN localization of GRB991014
  95. BeppoSAX ALERT: GRB991014
  96. GRB 990915 optical observations
  97. GRB 990907 optical observations
  98. BATSE GRB trigger criteria
  99. Optical Observations of GRB990907
  100. IPN error box for GRB990915 (=BATSE 7766)

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