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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. GRB000301C
  2. GRB 000301C : Optical Candidate
  3. Radio observations of the error box of GRB000301A
  4. GRB000301C: RXTE/ASM and IPN localizations
  5. GRB000301A [IPN Position]
  6. GRB000226 [IPN Position]
  7. HST Observations of GRB 990712
  8. GRB 000214 near-IR observations
  9. GRB 000115 Optical observations
  10. GRB 000214, Radio Observations
  11. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  12. GRB000210, Radio Observations
  13. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  14. GRB 000115, BVRI field photometry
  15. GRB000214: BeppoSAX GRBM and WFC Detection
  16. IPN annulus for GRB000214
  17. BATSE GRB trigger criterion changed
  18. Optical observations of GRB000210
  19. GRB000210 X-ray afterglow
  20. GRB000214: X-ray afterglow candidate
  21. GRB000214 refined BeppoSAX-WFC position
  22. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  23. GRB 000210: BATSE Observations
  24. Correction to Chandra Position of GRB000210 afterglow
  25. Optical observations of the Chandra X-ray source for GRB000210
  26. GRB000210, Radio Observations
  27. Optical candidate for GRB000210
  28. Chandra Observations of GRB000210 X-ray Afterglow
  29. IPN triangulation of GRB000210
  30. GRB000210: possible afterglow detection with BeppoSAX NFI
  31. GRB000201, Radio Observations
  32. GRB000210: BeppoSAX GRBM and WFC Detection
  33. SAX_WFC_GRB_NOTICE
  34. SAX_WFC_GRB_NOTICE
  35. Optical observations of GRB000131
  36. GRB000201 Optical Observations
  37. GRB 000201: TAROT optical observations
  38. GRB 000131 Optical Observations
  39. GRB000126 Optical Observations
  40. BATSE GRB trigger criteria changed
  41. GRB 991208, radio observations
  42. BATSE+IPN location of GRB000131
  43. IPN localization of GRB000131
  44. GRB 000126, optical observations
  45. GRB000126, optical observations
  46. BATSE location of GRB000126
  47. IPN localization of GRB000126
  48. GRB 000115 Optical observations
  49. BATSE Observations of GRB000115
  50. Correction to GCN 520 (IPN annulus for GRB000115)
  51. IPN annulus for GRB000115
  52. Second RXTE Observation of GRB 000115
  53. GRB991216, UBVRIJHK field photometry
  54. GRB991216 late optical observation
  55. Single IPN error box for GRB991229
  56. GCN resumes full operations
  57. GRB 991216 VLBA Observations
  58. BEPPOSAX GRBM Localization of GRB991226
  59. IPN error boxes for GRB991229
  60. GRB 991216: J band spectrophotometry
  61. GRB 991216: Detection of the Host and/or Absorber Galaxy
  62. IPN localization of GRB991226
  63. Single IPN error box for GRB991221
  64. IPN error boxes for GRB991221
  65. GRB 991216 RXTE ASM Observations
  66. IPN error box for GRB991216
  67. GRB 991216: Updated BATSE parameters
  68. Lowell/Perkins observation of GRB 991216
  69. GRB 991217 (SAX J2303.2+0015) Optical observations
  70. GRB991217/SAX J2303.2+0015, optical observations
  71. Chandra observation of the X-ray afterglow of GRB991216
  72. GRB 991216, optical observations
  73. GRB 991216 Optical Observations
  74. GRB 991216 Optical spectroscopy/imaging
  75. VLT spectra of GRB991216
  76. GRB991216 Optical and IR observations
  77. K observations of GRB991216
  78. SAX J2303.2+0015 Optical observations
  79. IR observations of GRB991216
  80. GRB991216 radio observations
  81. GRB 991217 (SAX J2303.2+0015) Optical observations
  82. GRB991216 radio observations
  83. GRB991216 Spectroscopy
  84. Lowell/Perkins observation of GRB 991216
  85. GRB991216, optical observations
  86. GRB991216 Optical and infrared observations of Beethoven Burst
  87. Refined IPN localization of GRB991216
  88. GRB 991216 Radio Observations
  89. GRB 991217
  90. GRB 991208 Keck Spectroscopy
  91. GRB 991208 Infrared Detection
  92. GRB991216
  93. GRB 991216--Summary of RXTE Observations
  94. GRB 991216 Optical Observations
  95. GRB 991216, optical observations
  96. GRB 991208 SAO-RAS Spectroscopy
  97. SAX J2303.2+0015: an x-ray/GRB?
  98. GRB 991216, Optical Transient
  99. GRB 991216, Optical Afterglow
  100. GRB991216 ('Beethoven Burst') B, R, and K Observations

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