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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. Radio observations of the error box of GRB000301A
  2. GRB000301C: RXTE/ASM and IPN localizations
  3. GRB000301A [IPN Position]
  4. GRB000226 [IPN Position]
  5. HST Observations of GRB 990712
  6. GRB 000214 near-IR observations
  7. GRB 000115 Optical observations
  8. GRB 000214, Radio Observations
  9. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  10. GRB000210, Radio Observations
  11. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  12. GRB 000115, BVRI field photometry
  13. GRB000214: BeppoSAX GRBM and WFC Detection
  14. IPN annulus for GRB000214
  15. BATSE GRB trigger criterion changed
  16. Optical observations of GRB000210
  17. GRB000210 X-ray afterglow
  18. GRB000214: X-ray afterglow candidate
  19. GRB000214 refined BeppoSAX-WFC position
  20. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  21. GRB 000210: BATSE Observations
  22. Correction to Chandra Position of GRB000210 afterglow
  23. Optical observations of the Chandra X-ray source for GRB000210
  24. GRB000210, Radio Observations
  25. Optical candidate for GRB000210
  26. Chandra Observations of GRB000210 X-ray Afterglow
  27. IPN triangulation of GRB000210
  28. GRB000210: possible afterglow detection with BeppoSAX NFI
  29. GRB000201, Radio Observations
  30. GRB000210: BeppoSAX GRBM and WFC Detection
  31. SAX_WFC_GRB_NOTICE
  32. SAX_WFC_GRB_NOTICE
  33. Optical observations of GRB000131
  34. GRB000201 Optical Observations
  35. GRB 000201: TAROT optical observations
  36. GRB 000131 Optical Observations
  37. GRB000126 Optical Observations
  38. BATSE GRB trigger criteria changed
  39. GRB 991208, radio observations
  40. BATSE+IPN location of GRB000131
  41. IPN localization of GRB000131
  42. GRB 000126, optical observations
  43. GRB000126, optical observations
  44. BATSE location of GRB000126
  45. IPN localization of GRB000126
  46. GRB 000115 Optical observations
  47. BATSE Observations of GRB000115
  48. Correction to GCN 520 (IPN annulus for GRB000115)
  49. IPN annulus for GRB000115
  50. Second RXTE Observation of GRB 000115
  51. GRB991216, UBVRIJHK field photometry
  52. GRB991216 late optical observation
  53. Single IPN error box for GRB991229
  54. GCN resumes full operations
  55. GRB 991216 VLBA Observations
  56. BEPPOSAX GRBM Localization of GRB991226
  57. IPN error boxes for GRB991229
  58. GRB 991216: J band spectrophotometry
  59. GRB 991216: Detection of the Host and/or Absorber Galaxy
  60. IPN localization of GRB991226
  61. Single IPN error box for GRB991221
  62. IPN error boxes for GRB991221
  63. GRB 991216 RXTE ASM Observations
  64. IPN error box for GRB991216
  65. GRB 991216: Updated BATSE parameters
  66. Lowell/Perkins observation of GRB 991216
  67. GRB 991217 (SAX J2303.2+0015) Optical observations
  68. GRB991217/SAX J2303.2+0015, optical observations
  69. Chandra observation of the X-ray afterglow of GRB991216
  70. GRB 991216, optical observations
  71. GRB 991216 Optical Observations
  72. GRB 991216 Optical spectroscopy/imaging
  73. VLT spectra of GRB991216
  74. GRB991216 Optical and IR observations
  75. K observations of GRB991216
  76. SAX J2303.2+0015 Optical observations
  77. IR observations of GRB991216
  78. GRB991216 radio observations
  79. GRB 991217 (SAX J2303.2+0015) Optical observations
  80. GRB991216 radio observations
  81. GRB991216 Spectroscopy
  82. Lowell/Perkins observation of GRB 991216
  83. GRB991216, optical observations
  84. GRB991216 Optical and infrared observations of Beethoven Burst
  85. Refined IPN localization of GRB991216
  86. GRB 991216 Radio Observations
  87. GRB 991217
  88. GRB 991208 Keck Spectroscopy
  89. GRB 991208 Infrared Detection
  90. GRB991216
  91. GRB 991216--Summary of RXTE Observations
  92. GRB 991216 Optical Observations
  93. GRB 991216, optical observations
  94. GRB 991208 SAO-RAS Spectroscopy
  95. SAX J2303.2+0015: an x-ray/GRB?
  96. GRB 991216, Optical Transient
  97. GRB 991216, Optical Afterglow
  98. GRB991216 ('Beethoven Burst') B, R, and K Observations
  99. GRB 991216: Comparison with DPOSS images
  100. GRB991216, infrared observations

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