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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. BATSE Observations of GRB000115
  2. Correction to GCN 520 (IPN annulus for GRB000115)
  3. IPN annulus for GRB000115
  4. Second RXTE Observation of GRB 000115
  5. GRB991216, UBVRIJHK field photometry
  6. GRB991216 late optical observation
  7. Single IPN error box for GRB991229
  8. GCN resumes full operations
  9. GRB 991216 VLBA Observations
  10. BEPPOSAX GRBM Localization of GRB991226
  11. IPN error boxes for GRB991229
  12. GRB 991216: J band spectrophotometry
  13. GRB 991216: Detection of the Host and/or Absorber Galaxy
  14. IPN localization of GRB991226
  15. Single IPN error box for GRB991221
  16. IPN error boxes for GRB991221
  17. GRB 991216 RXTE ASM Observations
  18. IPN error box for GRB991216
  19. GRB 991216: Updated BATSE parameters
  20. Lowell/Perkins observation of GRB 991216
  21. GRB 991217 (SAX J2303.2+0015) Optical observations
  22. GRB991217/SAX J2303.2+0015, optical observations
  23. Chandra observation of the X-ray afterglow of GRB991216
  24. GRB 991216, optical observations
  25. GRB 991216 Optical Observations
  26. GRB 991216 Optical spectroscopy/imaging
  27. VLT spectra of GRB991216
  28. GRB991216 Optical and IR observations
  29. K observations of GRB991216
  30. SAX J2303.2+0015 Optical observations
  31. IR observations of GRB991216
  32. GRB991216 radio observations
  33. GRB 991217 (SAX J2303.2+0015) Optical observations
  34. GRB991216 radio observations
  35. GRB991216 Spectroscopy
  36. Lowell/Perkins observation of GRB 991216
  37. GRB991216, optical observations
  38. GRB991216 Optical and infrared observations of Beethoven Burst
  39. Refined IPN localization of GRB991216
  40. GRB 991216 Radio Observations
  41. GRB 991217
  42. GRB 991208 Keck Spectroscopy
  43. GRB 991208 Infrared Detection
  44. GRB991216
  45. GRB 991216--Summary of RXTE Observations
  46. GRB 991216 Optical Observations
  47. GRB 991216, optical observations
  48. GRB 991208 SAO-RAS Spectroscopy
  49. SAX J2303.2+0015: an x-ray/GRB?
  50. GRB 991216, Optical Transient
  51. GRB 991216, Optical Afterglow
  52. GRB991216 ('Beethoven Burst') B, R, and K Observations
  53. GRB 991216: Comparison with DPOSS images
  54. GRB991216, infrared observations
  55. GRB991216 Optical Observations
  56. GRB 991208 optical observations
  57. Lowell/Perkins observation of GRB 991216
  58. GRB 991216 Optical Observation
  59. GRB 991208 Keck Spectroscopy
  60. GRB 991216: Extremely bright BATSE burst
  61. R-band Observations of GRB991208 at TNG
  62. GRB991208, optical observations
  63. GRB 991208 Keck Spectroscopy
  64. GRB991208 - millimeter detection
  65. GRB 991208, Optical Observation
  66. GRB991208 15-GHz observations
  67. GRB991208, optical observations
  68. GRB 991208 - OVRO detection
  69. GRB 991208 Optical Decay
  70. GRB 991208 optical observations
  71. GRB 991208 optical observations
  72. GRB 991208: Radio Observations
  73. IPN localization of GRB991208
  74. Optical Observations of GRB991105
  75. GRB991106: BeppoSAX/BATSE results
  76. GRB 991106, optical observations
  77. GRB991106, near-infrared observations
  78. BeppoSAX NFI Observation of GRB991106
  79. GRB 991106, radio observations
  80. GRB991106: the first BeppoSAX short GRB detection?
  81. GRB 991105: BATSE Observations
  82. IPN localization of GRB991105
  83. GRB 991106 Optical Observations
  84. GRB 991105, optical observations
  85. GRB991106, optical observation at SAO-RAS
  86. GRB 991106, LOTIS Optical Observations
  87. GRB 991106, optical observations
  88. BeppoSAX refined position for GRB991106
  89. BeppoSAX GRB Alert: GRB991106
  90. Revised BeppoSAX WFC position of GRB991105
  91. GRB991105: SAX-GRBM/-WFC detection
  92. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  93. GRB ALERT: GRB991105
  94. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  95. GRB 991014, Optical Observations
  96. GRB 991014 - BeppoSAX NFI observations
  97. GRB 991014, Optical Observations
  98. GRB 991014, radio observations
  99. GRB991014 BATSE Observations
  100. GRB 991014, Optical Observations

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