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

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