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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').

21221 results found.

  1. GRB020321 : Optical observations.
  2. GRB 020410, optical observations
  3. GRB 020331: Candidate Optical Afterglow
  4. GRB 020322: BeppoSAX observations of the X-ray afterglow
  5. SN 2002ap - peak brightness date (SN/GRB?)
  6. GRB020321: a faint BeppoSAX detection
  7. GRB020317, optical observations
  8. GRB020305, optical observations
  9. GRB020124, optical observations
  10. HETE 1896: Optical observations
  11. GRB011130 (=XRF011130), Optical Observations
  12. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  13. GRB 011030: K-band observations
  14. The X-ray Flash 011030 ('GRB 011030')
  15. GRB 011019 optical observation
  16. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  17. GRB 010921: The afterglow of HETE #1761
  18. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  19. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  20. GRB010921 Optical Observations
  21. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  22. HETE Trigger #1760 (GRB 010920B?): a new optical source
  23. HETE Trigger #1759 (GRB 010920?) optical observations
  24. BeppoSAX/GRBM detection of GRB 010801
  25. GCN and HETE status
  26. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  27. GRB 010629 Optical Observations
  28. IPN triangulation of GRB010613
  29. IPN triangulation of GRB010612
  30. GRB010518: a faint BeppoSAX detection
  31. GRB010324: BeppoSAX/GRBM data
  32. GRB 010214: X-Ray afterglow
  33. GRB010213, optical observations
  34. GRB010126: CONCAM crude optical limits during GRB
  35. HETE positions added to GCN
  36. CONCAM null result on GRB001005
  37. CONCAM crude optical limits before and after GRB000926
  38. GRB000607, optical observations
  39. GRB 000615: NIR observations
  40. IPN triangulation of GRB000519
  41. RXTE/ASM and IPN localization of GRB 000508B
  42. BeppoSAX GRB000424
  43. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  44. GRB000408, lotis optical observations
  45. GRB 000313 - optical transient in the BATSE error box
  46. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  47. BATSE GRB trigger criterion changed
  48. GRB000210 X-ray afterglow
  49. GRB 000210: BATSE Observations
  50. GRB000201 Optical Observations
  51. GRB 000201: TAROT optical observations
  52. BATSE GRB trigger criteria changed
  53. BATSE+IPN location of GRB000131
  54. BATSE location of GRB000126
  55. BATSE Observations of GRB000115
  56. Second RXTE Observation of GRB 000115
  57. Single IPN error box for GRB991229
  58. GRB 991216: Updated BATSE parameters
  59. GRB 991216--Summary of RXTE Observations
  60. GRB 991216: Extremely bright BATSE burst
  61. GRB991106: BeppoSAX/BATSE results
  62. BeppoSAX NFI Observation of GRB991106
  63. GRB 991105: BATSE Observations
  64. GRB991106, optical observation at SAO-RAS
  65. GRB 991106, LOTIS Optical Observations
  66. GRB991105: SAX-GRBM/-WFC detection
  67. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  68. GRB ALERT: GRB991105
  69. GRB 991014 - BeppoSAX NFI observations
  70. GRB991014 BATSE Observations
  71. Super-LOTIS optical observation of GRB991014
  72. BeppoSAX ALERT: GRB991014
  73. GRB 990915 optical observations
  74. BATSE GRB trigger criteria
  75. IPN error box for GRB990915 (=BATSE 7766)
  76. IPN localization of BATSE #7766 (GRB990915)
  77. GRB990806: BATSE Observations
  78. BeppoSAX ALERT GRB990806: Summer GRB
  79. BeppoSAX NFI Observation of GRB990705
  80. BeppoSAX NFI Observation of GRB990705
  81. GRB990704
  82. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  83. BeppoSAX: GRB990625
  84. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  85. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  86. BeppoSAX: A new fast X-ray transient
  87. GRB990510: X-ray afterglow
  88. GRB 990510: BATSE Observations
  89. GRB 990506: BATSE Observations
  90. GRB990323 PRECISE IPN POSITION
  91. GRB990316: simultaneous optical observation
  92. GRB990316 - Optical null results
  93. ASM/IPN error box for GRB 990308 (BATSE #7457)
  94. GRB 990308a and GRB 990308b
  95. BATSE Resumes Normal Operations
  96. Search for Potential Images of GRB 990123
  97. Search for Potential Images of GRB 990123
  98. GRB990123, OSSE observations
  99. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  100. GRB 990123: BATSE Observations

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