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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"

36947 results found.

  1. BATSE GRB trigger criterion changed
  2. GRB000210 X-ray afterglow
  3. GRB000214: X-ray afterglow candidate
  4. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  5. GRB 000210: BATSE Observations
  6. Optical observations of the Chandra X-ray source for GRB000210
  7. Chandra Observations of GRB000210 X-ray Afterglow
  8. IPN triangulation of GRB000210
  9. GRB 000201: TAROT optical observations
  10. GRB 000131 Optical Observations
  11. GRB000126 Optical Observations
  12. BATSE GRB trigger criteria changed
  13. GRB 991208, radio observations
  14. BATSE+IPN location of GRB000131
  15. IPN localization of GRB000131
  16. GRB 000126, optical observations
  17. GRB000126, optical observations
  18. BATSE location of GRB000126
  19. IPN localization of GRB000126
  20. GRB 000115 Optical observations
  21. BATSE Observations of GRB000115
  22. Second RXTE Observation of GRB 000115
  23. GRB991216, UBVRIJHK field photometry
  24. Single IPN error box for GRB991229
  25. GRB 991216 VLBA Observations
  26. BEPPOSAX GRBM Localization of GRB991226
  27. IPN error boxes for GRB991229
  28. GRB 991216: J band spectrophotometry
  29. GRB 991216: Detection of the Host and/or Absorber Galaxy
  30. IPN localization of GRB991226
  31. Single IPN error box for GRB991221
  32. IPN error boxes for GRB991221
  33. GRB 991216 RXTE ASM Observations
  34. IPN error box for GRB991216
  35. GRB 991216: Updated BATSE parameters
  36. Lowell/Perkins observation of GRB 991216
  37. GRB 991217 (SAX J2303.2+0015) Optical observations
  38. Chandra observation of the X-ray afterglow of GRB991216
  39. GRB 991216, optical observations
  40. GRB 991216 Optical Observations
  41. GRB 991216 Optical spectroscopy/imaging
  42. K observations of GRB991216
  43. GRB 991217 (SAX J2303.2+0015) Optical observations
  44. GRB991216 Spectroscopy
  45. Lowell/Perkins observation of GRB 991216
  46. GRB991216, optical observations
  47. Refined IPN localization of GRB991216
  48. GRB 991216 Radio Observations
  49. GRB 991217
  50. GRB 991208 Keck Spectroscopy
  51. GRB 991208 Infrared Detection
  52. GRB 991216--Summary of RXTE Observations
  53. GRB 991216 Optical Observations
  54. GRB 991216, optical observations
  55. GRB 991208 SAO-RAS Spectroscopy
  56. SAX J2303.2+0015: an x-ray/GRB?
  57. GRB 991216, Optical Transient
  58. GRB 991216, Optical Afterglow
  59. GRB 991216: Comparison with DPOSS images
  60. GRB 991208 optical observations
  61. Lowell/Perkins observation of GRB 991216
  62. GRB 991216 Optical Observation
  63. GRB 991208 Keck Spectroscopy
  64. GRB 991216: Extremely bright BATSE burst
  65. GRB991208, optical observations
  66. GRB 991208 Keck Spectroscopy
  67. GRB991208 - millimeter detection
  68. GRB 991208, Optical Observation
  69. GRB 991208 - OVRO detection
  70. GRB 991208 Optical Decay
  71. GRB 991208 optical observations
  72. GRB 991208 optical observations
  73. GRB 991208: Radio Observations
  74. IPN localization of GRB991208
  75. Optical Observations of GRB991105
  76. GRB991106: BeppoSAX/BATSE results
  77. GRB 991106, optical observations
  78. GRB991106, near-infrared observations
  79. BeppoSAX NFI Observation of GRB991106
  80. GRB 991106, radio observations
  81. GRB991106: the first BeppoSAX short GRB detection?
  82. GRB 991105: BATSE Observations
  83. IPN localization of GRB991105
  84. GRB 991106 Optical Observations
  85. GRB 991105, optical observations
  86. GRB991106, optical observation at SAO-RAS
  87. GRB 991106, LOTIS Optical Observations
  88. GRB 991106, optical observations
  89. BeppoSAX GRB Alert: GRB991106
  90. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  91. GRB ALERT: GRB991105
  92. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  93. GRB 991014, Optical Observations
  94. GRB 991014 - BeppoSAX NFI observations
  95. GRB 991014, Optical Observations
  96. GRB 991014, radio observations
  97. GRB991014 BATSE Observations
  98. GRB 991014, Optical Observations
  99. GRB 991014, optical observations
  100. Super-LOTIS optical observation of GRB991014

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