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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"

35341 results found.

  1. Chandra Observations of GRB000210 X-ray Afterglow
  2. IPN triangulation of GRB000210
  3. GRB 000201: TAROT optical observations
  4. GRB 000131 Optical Observations
  5. GRB000126 Optical Observations
  6. BATSE GRB trigger criteria changed
  7. GRB 991208, radio observations
  8. BATSE+IPN location of GRB000131
  9. IPN localization of GRB000131
  10. GRB 000126, optical observations
  11. GRB000126, optical observations
  12. BATSE location of GRB000126
  13. IPN localization of GRB000126
  14. GRB 000115 Optical observations
  15. BATSE Observations of GRB000115
  16. Second RXTE Observation of GRB 000115
  17. GRB991216, UBVRIJHK field photometry
  18. Single IPN error box for GRB991229
  19. GRB 991216 VLBA Observations
  20. BEPPOSAX GRBM Localization of GRB991226
  21. IPN error boxes for GRB991229
  22. GRB 991216: J band spectrophotometry
  23. GRB 991216: Detection of the Host and/or Absorber Galaxy
  24. IPN localization of GRB991226
  25. Single IPN error box for GRB991221
  26. IPN error boxes for GRB991221
  27. GRB 991216 RXTE ASM Observations
  28. IPN error box for GRB991216
  29. GRB 991216: Updated BATSE parameters
  30. Lowell/Perkins observation of GRB 991216
  31. GRB 991217 (SAX J2303.2+0015) Optical observations
  32. Chandra observation of the X-ray afterglow of GRB991216
  33. GRB 991216, optical observations
  34. GRB 991216 Optical Observations
  35. GRB 991216 Optical spectroscopy/imaging
  36. K observations of GRB991216
  37. GRB 991217 (SAX J2303.2+0015) Optical observations
  38. GRB991216 Spectroscopy
  39. Lowell/Perkins observation of GRB 991216
  40. GRB991216, optical observations
  41. Refined IPN localization of GRB991216
  42. GRB 991216 Radio Observations
  43. GRB 991217
  44. GRB 991208 Keck Spectroscopy
  45. GRB 991208 Infrared Detection
  46. GRB 991216--Summary of RXTE Observations
  47. GRB 991216 Optical Observations
  48. GRB 991216, optical observations
  49. GRB 991208 SAO-RAS Spectroscopy
  50. SAX J2303.2+0015: an x-ray/GRB?
  51. GRB 991216, Optical Transient
  52. GRB 991216, Optical Afterglow
  53. GRB 991216: Comparison with DPOSS images
  54. GRB 991208 optical observations
  55. Lowell/Perkins observation of GRB 991216
  56. GRB 991216 Optical Observation
  57. GRB 991208 Keck Spectroscopy
  58. GRB 991216: Extremely bright BATSE burst
  59. GRB991208, optical observations
  60. GRB 991208 Keck Spectroscopy
  61. GRB991208 - millimeter detection
  62. GRB 991208, Optical Observation
  63. GRB 991208 - OVRO detection
  64. GRB 991208 Optical Decay
  65. GRB 991208 optical observations
  66. GRB 991208 optical observations
  67. GRB 991208: Radio Observations
  68. IPN localization of GRB991208
  69. Optical Observations of GRB991105
  70. GRB991106: BeppoSAX/BATSE results
  71. GRB 991106, optical observations
  72. GRB991106, near-infrared observations
  73. BeppoSAX NFI Observation of GRB991106
  74. GRB 991106, radio observations
  75. GRB991106: the first BeppoSAX short GRB detection?
  76. GRB 991105: BATSE Observations
  77. IPN localization of GRB991105
  78. GRB 991106 Optical Observations
  79. GRB 991105, optical observations
  80. GRB991106, optical observation at SAO-RAS
  81. GRB 991106, LOTIS Optical Observations
  82. GRB 991106, optical observations
  83. BeppoSAX GRB Alert: GRB991106
  84. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  85. GRB ALERT: GRB991105
  86. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  87. GRB 991014, Optical Observations
  88. GRB 991014 - BeppoSAX NFI observations
  89. GRB 991014, Optical Observations
  90. GRB 991014, radio observations
  91. GRB991014 BATSE Observations
  92. GRB 991014, Optical Observations
  93. GRB 991014, optical observations
  94. Super-LOTIS optical observation of GRB991014
  95. IPN/NFI error box for GRB991014
  96. IPN localization of GRB991014 - CORRECTION
  97. IPN localization of GRB991014
  98. BeppoSAX ALERT: GRB991014
  99. GRB 990915 optical observations
  100. GRB 990907 optical observations

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