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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"

35948 results found.

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

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