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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. Further Optical Observations of GRB 010324
  2. GRB010222, CXO X-ray observations
  3. GRB 010326A: Further optical observations
  4. GRB010324: BeppoSAX/GRBM data
  5. GRB 010326B: Optical observations
  6. GRB010324, optical observations
  7. GRB010326B: Localization by HETE (2nd GRB for this date)
  8. GRB 010326: Optical observations
  9. GRB 010326 optical observations
  10. GRB010326: Refined Localization by HETE
  11. GRB010326: Localization by HETE
  12. Duration, ECT, peak flux and fluence of GRB010324
  13. Optical Observations of GRB 010324
  14. IPN TRIANGULATION OF GRB010324
  15. GRB990705, VLT-FORS1 observations of the host galaxy
  16. GRB010222, late-time optical observation
  17. Support extension to the BeppoSAX mission
  18. GRB 010222 - HEGRA GeV/TeV Observations
  19. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  20. GRB010222: Chandra X-ray Observatory Observation
  21. GRB010222: Sub-millimeter vanishing act
  22. GRB010222 - Optical observation
  23. GRB 010222, Optical Observations
  24. GRB010220 optical obsercations
  25. GRB010222 - Optical observation
  26. GRB 010222: High-Resolution Keck Spectroscopy
  27. GRB010222: Optical observation and decay
  28. GRB 010214, I-band data
  29. Sub-millimeter Excess/GRB 010222
  30. GRB 010222
  31. GRB 010222 HST/Chandra TOO
  32. GRB 010222
  33. GRB010222 further R-band photometry
  34. GRB010222: R-band data
  35. GRB010222 Optical observations
  36. GRB 010222: Keck Spectroscopy
  37. GRB010214, field photometry
  38. GRB010222, field photometry
  39. GRB010222 further R-band photometry
  40. GRB010222, possible increase of optical decay slope
  41. GRB 010222 Kyoto optical observation
  42. GRB010222: fading behavior
  43. GRB 010222 BV optical observations
  44. GRB010220, Optical Observations
  45. GRB010222 R-BAND OBSERVATION
  46. GRB 010220: Near-IR Observations
  47. GRB010214 follow-up from Hanle
  48. GRB 010222: Near-IR Observations
  49. GRB 010222: Optical Observations
  50. GRB 010222, Decay Slope Confirmed
  51. GRB010222: Another absorption line system
  52. GRB010222: Optical decay slope
  53. GRB 010214, Optical Observations
  54. GRB010222: Sub-millimeter detection
  55. GRB010222: R-band fading behavior
  56. GRB010222: Optical Observations
  57. GRB010222, radio observations
  58. GRB010222, optical observations
  59. GRB010222: BeppoSAX/NFI Observations
  60. Redshift of the Optical Transient of GRB010222
  61. GRB010214B,Gamma Ray Observations
  62. GRB010222: possible optical counterpart
  63. GRB010222
  64. GRB010222
  65. GRB010222: BeppoSAX refined position
  66. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  67. GRB010220, Radio and Optical Observations
  68. GRB 010220, simultaneous optical observations
  69. GRB010220: BeppoSAX WFC and GRBM preliminary data
  70. GRB010214, candidate optical afterglow
  71. GRB010214, optical observations
  72. BeppoSAX GRB010220: refined position
  73. BeppoSAX ALERT: GRB010220
  74. GRB010214: BeppoSAX WFC and GRBM preliminary data
  75. GRB 010214: X-Ray afterglow
  76. GRB 010214, Optical Observations
  77. GRB 010214 optical observation
  78. GRB010213, Radio Observations
  79. GRB010213 Optical Observation
  80. GRB010213, Radio Observations
  81. J-Band Observation of GRB 010214.
  82. GRB010214, Radio Observations
  83. GRB010214, optical observations
  84. GRB010213, optical observations
  85. GRB010213, Near-IR observations
  86. Possible InfraRed Transient of GRB 010214.
  87. GRB010214 Optical Observation
  88. GRB010214: BeppoSAX/NFI Observations
  89. GRB010213 (HETE) TAROT observations
  90. GRB 010214, optical observations
  91. GRB010213 detected by HETE
  92. GRB010214 refined WFC position
  93. BeppoSAX ALERT: GRB010214
  94. IPN Status Report
  95. HETE Status
  96. GRB010126 opt. obs.
  97. IPN/RXTE TRIANGULATION OF GRB010126
  98. GRB010126: CONCAM crude optical limits during GRB
  99. GRB010126, TNG R-band observations
  100. GRB010126 Optical Observations

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