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

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