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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. IPN localization of BATSE #7766 (GRB990915)
  2. GRB990907: BeppoSAX follow up and X-ray afterglow
  3. GRB990907 and 990908
  4. IPN localization of GRB990907
  5. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  6. GRB990907: refined WFC position
  7. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  8. GRB 990712 Late Optical Decay and Host Galaxy
  9. GRB 990712, Optical Observation
  10. GRB990806 BeppoSAX follow up
  11. GRB990806: BATSE Observations
  12. GRB 990806 Optical observations
  13. Optical Observations of GRB990806
  14. GRB 990806, Optical Observations
  15. GRB 990806, optical observations
  16. GRB 990806, Optical Observations
  17. GRB990806 UBVRIJHK observations
  18. GRB990806: possible X-ray afterglow, BeppoSAX
  19. BeppoSAX ALERT GRB990806: Summer GRB
  20. GRB 990712 Optical Observations
  21. GRB990705: No Evidence for Neutrino Signal
  22. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  23. VLT spectrum of GRB990712
  24. GRB 990712
  25. Late-time HST/STIS Observations of GRB 990510
  26. Refined BeppoSAX-WFC position of GRB990712
  27. BeppoSAX NFI Observation of GRB990705
  28. BeppoSAX NFI Observation of GRB990705
  29. Updated Astrometry for the IR Counterpart of GRB990705
  30. GRB 990705, R-band observations
  31. Updated IPN localization of GRB990705
  32. IPN localization of GRB990704
  33. IPN localization of GRB990705
  34. Infrared and Optical Observations of GRB990705
  35. GRB 990705, radio observations
  36. GRB990704: SAX-NFI results summary
  37. GRB990704 radio and optical observations
  38. BeppoSAX GRB990705: possible X-ray afterglow
  39. GRB 990704 X-ray Observations
  40. GRB 990704 Optical Observations
  41. GRB 990704, optical observations
  42. GRB990704
  43. GRB990705: Intriguing Positional Coincidences
  44. GRB990704
  45. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  46. GRB990704, optical observations
  47. GRB990704: possible X-ray afterglow
  48. Identification of a possible optical counterpart for GRB990704
  49. GRB990704
  50. Refined BeppoSAX-WFC position of GRB990704
  51. GRB990704: BeppoSAX detection
  52. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  53. Optical Observations of GRB990627
  54. GRB 990627, radio observations
  55. GRB990627: BeppoSAX-WFC final location
  56. BeppoSAX: GRB990625
  57. Late-time HST/STIS Observation of GRB 990123
  58. GRB 990506 - clarification to GCN 352
  59. GRB 990506 - Optical Observations
  60. Optical Observations of GRB 990506
  61. GRB 990506 Radio Transient
  62. GRB990527 Optical Observations
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. IPN error box for GRB990527
  65. Late Afterglows of GRBs 990510, 990123
  66. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  67. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  68. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  69. GRB 990506 optical observation
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  71. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  72. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. radio observations of X-ray/GRB transient field
  75. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  76. Optical report on X-ray/GRB transient
  77. radio detection of X-ray/GRB transient
  78. BeppoSAX: A new fast X-ray transient
  79. GRB 990510: optical observations
  80. GRB990510: photometric and spectroscopic observations with the VLT
  81. GRB 990510: optical linear polarization
  82. GRB 990510: optical observations
  83. GRB990510, VI observations
  84. GRB 990506 R band observations
  85. GRB990510: X-ray afterglow
  86. GRB 990510: optical observation
  87. VLT spectrum of GRB990510
  88. GRB 990510: Broad Band Break
  89. GRB 990510: BATSE Observations
  90. GRB990510: optical observation
  91. GRB 990510 Optical Observations
  92. GRB 990510, BVI photometry
  93. GRB 990510 optical observations
  94. GRB 990510: BeppoSAX/GRBM observations
  95. GRB990510 optical observations
  96. GRB990510
  97. GRB 990510 optical observations
  98. GRB 990510 optical observations
  99. Galactic extinction towards GRB 990510
  100. GRB990510: NFI X-ray source

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