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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').
  1. GRB000226 [IPN Position]
  2. HST Observations of GRB 990712
  3. GRB 000214 near-IR observations
  4. GRB 000115 Optical observations
  5. GRB 000214, Radio Observations
  6. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  7. GRB000210, Radio Observations
  8. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  9. GRB 000115, BVRI field photometry
  10. GRB000214: BeppoSAX GRBM and WFC Detection
  11. IPN annulus for GRB000214
  12. BATSE GRB trigger criterion changed
  13. Optical observations of GRB000210
  14. GRB000210 X-ray afterglow
  15. GRB000214: X-ray afterglow candidate
  16. GRB000214 refined BeppoSAX-WFC position
  17. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  18. GRB 000210: BATSE Observations
  19. Correction to Chandra Position of GRB000210 afterglow
  20. Optical observations of the Chandra X-ray source for GRB000210
  21. GRB000210, Radio Observations
  22. Optical candidate for GRB000210
  23. Chandra Observations of GRB000210 X-ray Afterglow
  24. IPN triangulation of GRB000210
  25. GRB000210: possible afterglow detection with BeppoSAX NFI
  26. GRB000201, Radio Observations
  27. GRB000210: BeppoSAX GRBM and WFC Detection
  28. SAX_WFC_GRB_NOTICE
  29. SAX_WFC_GRB_NOTICE
  30. Optical observations of GRB000131
  31. GRB000201 Optical Observations
  32. GRB 000201: TAROT optical observations
  33. GRB 000131 Optical Observations
  34. GRB000126 Optical Observations
  35. BATSE GRB trigger criteria changed
  36. GRB 991208, radio observations
  37. BATSE+IPN location of GRB000131
  38. IPN localization of GRB000131
  39. GRB 000126, optical observations
  40. GRB000126, optical observations
  41. BATSE location of GRB000126
  42. IPN localization of GRB000126
  43. GRB 000115 Optical observations
  44. BATSE Observations of GRB000115
  45. Correction to GCN 520 (IPN annulus for GRB000115)
  46. IPN annulus for GRB000115
  47. Second RXTE Observation of GRB 000115
  48. GRB991216, UBVRIJHK field photometry
  49. GRB991216 late optical observation
  50. Single IPN error box for GRB991229
  51. GCN resumes full operations
  52. GRB 991216 VLBA Observations
  53. BEPPOSAX GRBM Localization of GRB991226
  54. IPN error boxes for GRB991229
  55. GRB 991216: J band spectrophotometry
  56. GRB 991216: Detection of the Host and/or Absorber Galaxy
  57. IPN localization of GRB991226
  58. Single IPN error box for GRB991221
  59. IPN error boxes for GRB991221
  60. GRB 991216 RXTE ASM Observations
  61. IPN error box for GRB991216
  62. GRB 991216: Updated BATSE parameters
  63. Lowell/Perkins observation of GRB 991216
  64. GRB 991217 (SAX J2303.2+0015) Optical observations
  65. GRB991217/SAX J2303.2+0015, optical observations
  66. Chandra observation of the X-ray afterglow of GRB991216
  67. GRB 991216, optical observations
  68. GRB 991216 Optical Observations
  69. GRB 991216 Optical spectroscopy/imaging
  70. VLT spectra of GRB991216
  71. GRB991216 Optical and IR observations
  72. K observations of GRB991216
  73. SAX J2303.2+0015 Optical observations
  74. IR observations of GRB991216
  75. GRB991216 radio observations
  76. GRB 991217 (SAX J2303.2+0015) Optical observations
  77. GRB991216 radio observations
  78. GRB991216 Spectroscopy
  79. Lowell/Perkins observation of GRB 991216
  80. GRB991216, optical observations
  81. GRB991216 Optical and infrared observations of Beethoven Burst
  82. Refined IPN localization of GRB991216
  83. GRB 991216 Radio Observations
  84. GRB 991217
  85. GRB 991208 Keck Spectroscopy
  86. GRB 991208 Infrared Detection
  87. GRB991216
  88. GRB 991216--Summary of RXTE Observations
  89. GRB 991216 Optical Observations
  90. GRB 991216, optical observations
  91. GRB 991208 SAO-RAS Spectroscopy
  92. SAX J2303.2+0015: an x-ray/GRB?
  93. GRB 991216, Optical Transient
  94. GRB 991216, Optical Afterglow
  95. GRB991216 ('Beethoven Burst') B, R, and K Observations
  96. GRB 991216: Comparison with DPOSS images
  97. GRB991216, infrared observations
  98. GRB991216 Optical Observations
  99. GRB 991208 optical observations
  100. Lowell/Perkins observation of GRB 991216

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