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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. IPN localization of GRB000131
  2. GRB 000126, optical observations
  3. GRB000126, optical observations
  4. BATSE location of GRB000126
  5. IPN localization of GRB000126
  6. GRB 000115 Optical observations
  7. BATSE Observations of GRB000115
  8. Correction to GCN 520 (IPN annulus for GRB000115)
  9. IPN annulus for GRB000115
  10. Second RXTE Observation of GRB 000115
  11. GRB991216, UBVRIJHK field photometry
  12. GRB991216 late optical observation
  13. Single IPN error box for GRB991229
  14. GCN resumes full operations
  15. GRB 991216 VLBA Observations
  16. BEPPOSAX GRBM Localization of GRB991226
  17. IPN error boxes for GRB991229
  18. GRB 991216: J band spectrophotometry
  19. GRB 991216: Detection of the Host and/or Absorber Galaxy
  20. IPN localization of GRB991226
  21. Single IPN error box for GRB991221
  22. IPN error boxes for GRB991221
  23. GRB 991216 RXTE ASM Observations
  24. IPN error box for GRB991216
  25. GRB 991216: Updated BATSE parameters
  26. Lowell/Perkins observation of GRB 991216
  27. GRB 991217 (SAX J2303.2+0015) Optical observations
  28. GRB991217/SAX J2303.2+0015, optical observations
  29. Chandra observation of the X-ray afterglow of GRB991216
  30. GRB 991216, optical observations
  31. GRB 991216 Optical Observations
  32. GRB 991216 Optical spectroscopy/imaging
  33. VLT spectra of GRB991216
  34. GRB991216 Optical and IR observations
  35. K observations of GRB991216
  36. SAX J2303.2+0015 Optical observations
  37. IR observations of GRB991216
  38. GRB991216 radio observations
  39. GRB 991217 (SAX J2303.2+0015) Optical observations
  40. GRB991216 radio observations
  41. GRB991216 Spectroscopy
  42. Lowell/Perkins observation of GRB 991216
  43. GRB991216, optical observations
  44. GRB991216 Optical and infrared observations of Beethoven Burst
  45. Refined IPN localization of GRB991216
  46. GRB 991216 Radio Observations
  47. GRB 991217
  48. GRB 991208 Keck Spectroscopy
  49. GRB 991208 Infrared Detection
  50. GRB991216
  51. GRB 991216--Summary of RXTE Observations
  52. GRB 991216 Optical Observations
  53. GRB 991216, optical observations
  54. GRB 991208 SAO-RAS Spectroscopy
  55. SAX J2303.2+0015: an x-ray/GRB?
  56. GRB 991216, Optical Transient
  57. GRB 991216, Optical Afterglow
  58. GRB991216 ('Beethoven Burst') B, R, and K Observations
  59. GRB 991216: Comparison with DPOSS images
  60. GRB991216, infrared observations
  61. GRB991216 Optical Observations
  62. GRB 991208 optical observations
  63. Lowell/Perkins observation of GRB 991216
  64. GRB 991216 Optical Observation
  65. GRB 991208 Keck Spectroscopy
  66. GRB 991216: Extremely bright BATSE burst
  67. R-band Observations of GRB991208 at TNG
  68. GRB991208, optical observations
  69. GRB 991208 Keck Spectroscopy
  70. GRB991208 - millimeter detection
  71. GRB 991208, Optical Observation
  72. GRB991208 15-GHz observations
  73. GRB991208, optical observations
  74. GRB 991208 - OVRO detection
  75. GRB 991208 Optical Decay
  76. GRB 991208 optical observations
  77. GRB 991208 optical observations
  78. GRB 991208: Radio Observations
  79. IPN localization of GRB991208
  80. Optical Observations of GRB991105
  81. GRB991106: BeppoSAX/BATSE results
  82. GRB 991106, optical observations
  83. GRB991106, near-infrared observations
  84. BeppoSAX NFI Observation of GRB991106
  85. GRB 991106, radio observations
  86. GRB991106: the first BeppoSAX short GRB detection?
  87. GRB 991105: BATSE Observations
  88. IPN localization of GRB991105
  89. GRB 991106 Optical Observations
  90. GRB 991105, optical observations
  91. GRB991106, optical observation at SAO-RAS
  92. GRB 991106, LOTIS Optical Observations
  93. GRB 991106, optical observations
  94. BeppoSAX refined position for GRB991106
  95. BeppoSAX GRB Alert: GRB991106
  96. Revised BeppoSAX WFC position of GRB991105
  97. GRB991105: SAX-GRBM/-WFC detection
  98. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  99. GRB ALERT: GRB991105
  100. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI

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