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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"

37071 results found.

  1. GRB 000115, BVRI field photometry
  2. IPN annulus for GRB000214
  3. BATSE GRB trigger criterion changed
  4. GRB000210 X-ray afterglow
  5. GRB000214: X-ray afterglow candidate
  6. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  7. GRB 000210: BATSE Observations
  8. Optical observations of the Chandra X-ray source for GRB000210
  9. Chandra Observations of GRB000210 X-ray Afterglow
  10. IPN triangulation of GRB000210
  11. GRB000210: possible afterglow detection with BeppoSAX NFI
  12. GRB000201 Optical Observations
  13. GRB 000201: TAROT optical observations
  14. GRB 000131 Optical Observations
  15. GRB000126 Optical Observations
  16. BATSE GRB trigger criteria changed
  17. GRB 991208, radio observations
  18. BATSE+IPN location of GRB000131
  19. IPN localization of GRB000131
  20. GRB 000126, optical observations
  21. GRB000126, optical observations
  22. BATSE location of GRB000126
  23. IPN localization of GRB000126
  24. GRB 000115 Optical observations
  25. BATSE Observations of GRB000115
  26. Second RXTE Observation of GRB 000115
  27. GRB991216, UBVRIJHK field photometry
  28. GRB991216 late optical observation
  29. Single IPN error box for GRB991229
  30. GRB 991216 VLBA Observations
  31. BEPPOSAX GRBM Localization of GRB991226
  32. IPN error boxes for GRB991229
  33. GRB 991216: J band spectrophotometry
  34. GRB 991216: Detection of the Host and/or Absorber Galaxy
  35. IPN localization of GRB991226
  36. Single IPN error box for GRB991221
  37. IPN error boxes for GRB991221
  38. GRB 991216 RXTE ASM Observations
  39. IPN error box for GRB991216
  40. GRB 991216: Updated BATSE parameters
  41. Lowell/Perkins observation of GRB 991216
  42. GRB 991217 (SAX J2303.2+0015) Optical observations
  43. Chandra observation of the X-ray afterglow of GRB991216
  44. GRB 991216, optical observations
  45. GRB 991216 Optical Observations
  46. GRB 991216 Optical spectroscopy/imaging
  47. K observations of GRB991216
  48. GRB 991217 (SAX J2303.2+0015) Optical observations
  49. GRB991216 Spectroscopy
  50. Lowell/Perkins observation of GRB 991216
  51. GRB991216, optical observations
  52. GRB991216 Optical and infrared observations of Beethoven Burst
  53. Refined IPN localization of GRB991216
  54. GRB 991216 Radio Observations
  55. GRB 991217
  56. GRB 991208 Keck Spectroscopy
  57. GRB 991208 Infrared Detection
  58. GRB991216
  59. GRB 991216--Summary of RXTE Observations
  60. GRB 991216 Optical Observations
  61. GRB 991216, optical observations
  62. GRB 991208 SAO-RAS Spectroscopy
  63. SAX J2303.2+0015: an x-ray/GRB?
  64. GRB 991216, Optical Transient
  65. GRB 991216, Optical Afterglow
  66. GRB 991216: Comparison with DPOSS images
  67. GRB991216 Optical Observations
  68. GRB 991208 optical observations
  69. Lowell/Perkins observation of GRB 991216
  70. GRB 991216 Optical Observation
  71. GRB 991208 Keck Spectroscopy
  72. GRB 991216: Extremely bright BATSE burst
  73. GRB991208, optical observations
  74. GRB 991208 Keck Spectroscopy
  75. GRB991208 - millimeter detection
  76. GRB 991208, Optical Observation
  77. GRB991208 15-GHz observations
  78. GRB 991208 - OVRO detection
  79. GRB 991208 Optical Decay
  80. GRB 991208 optical observations
  81. GRB 991208 optical observations
  82. GRB 991208: Radio Observations
  83. IPN localization of GRB991208
  84. Optical Observations of GRB991105
  85. GRB991106: BeppoSAX/BATSE results
  86. GRB 991106, optical observations
  87. GRB991106, near-infrared observations
  88. BeppoSAX NFI Observation of GRB991106
  89. GRB 991106, radio observations
  90. GRB991106: the first BeppoSAX short GRB detection?
  91. GRB 991105: BATSE Observations
  92. IPN localization of GRB991105
  93. GRB 991106 Optical Observations
  94. GRB 991105, optical observations
  95. GRB991106, optical observation at SAO-RAS
  96. GRB 991106, LOTIS Optical Observations
  97. GRB 991106, optical observations
  98. BeppoSAX GRB Alert: GRB991106
  99. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  100. GRB ALERT: GRB991105

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