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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').

17828 results found.

  1. GRB 060510B: Swift detection of a burst
  2. GRB 060510: Swift detection of a burst with optical transient
  3. GRB060502B: improvement in the XRT afterglow position
  4. GRB 060507: BART limit
  5. GRB 060507: Final Refined analysis of the Swift-BAT burst
  6. GRB 060507: Swift-BAT Refined Analysis
  7. GRB 060507: Swift/UVOT Upper Limits
  8. GRB 060507: Swift XRT Team Refined Analysis
  9. GRB 060507: MDM Optical Upper Limit
  10. GRB060507: Swift XRT position
  11. GRB 060507: Swift detection of a burst
  12. GRB060505: Swift/UVOT Observations
  13. GRB 060505: Swift XRT Team Refined Analysis
  14. GRB 060505: Swift XRT afterglow canditate position
  15. GRB 060505: Swift-BAT detection of a weak burst
  16. GRB 060502B MDM Follow-up Observation
  17. GRB060502A, optical observation
  18. GRB 060502B: Swift/UVOT upper limits
  19. GRB 060502A: Swift/UVOT source detection
  20. GRB 060502B: MDM Optical Observation
  21. GRB 060502B: Refined analysis of the Swift-BAT short burst
  22. GRB060502B: Swift XRT Team refined analysis
  23. GRB060502B: correction to XRT position
  24. GRB 060502B: MASTER optical observations
  25. GRB 060502B: Swift detection of a short burst
  26. GRB060502: Swift-XRT refined analysis
  27. GRB 060502: Swift-BAT refined analysis
  28. GRB 060502: APO Spectroscopic Observations
  29. GRB060501: Swift UVOT followup observations
  30. GRB060502: Super-LOTIS Observations
  31. GRB 060502: Swift detection of a burst with an optical counterpart
  32. GRB 060501: MDM Observations
  33. GRB060501: Super-LOTIS observations
  34. GRB060501: P60 imaging and afterglow candidate
  35. GRB 060501: Refined analysis of the Swift-BAT burst
  36. GRB060501: Swift XRT position
  37. GRB 060501: ROTSE-III Optical Limits
  38. GRB 060501: Swift detection of a burst
  39. GRB060428B: optical observation
  40. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  41. GRB 060428B: MDM Observations
  42. GRB060428B: Swift XRT Team refined analysis
  43. GRB 060427B: IPN localization of a short hard burst
  44. GRB 060428B: Refined analysis of the Swift-BAT burst
  45. GRB 060428B: KAIT observations
  46. GRB060428A: Swift/UVOT observations.
  47. GRB060428B, optical observation
  48. GRB 060428A: Refined analysis of the Swift-BAT burst
  49. GRB060428A: Swift XRT Team refined analysis
  50. GRB 060428B: Swift detection of a burst
  51. GRB 060428: Swift detection of a burst
  52. GRB 060427: NOT observations
  53. GRB 060427: Swift/UVOT upper limits.
  54. GRB 060427: Refined analysis of the Swift-BAT burst
  55. GRB060427: Swift XRT Team refined analysis
  56. GRB060418: Swift XRT Team Further Refined Analysis
  57. GRB 060427, optical observation
  58. GRB 060427: Swift detection of a burst
  59. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  60. GRB 060424: Refined analysis of the Swift-BAT burst
  61. GRB 060424: Swift detection of a burst
  62. Swift-BAT detection of Mrk 421
  63. GRB060421: Swift/UVOT observations
  64. GRB 060421: Swift-BAT Refined Analysis
  65. GRB 060421: Swift-XRT refined analysis
  66. GRB 060418: prediction of t_break
  67. Konus-Wind observation of GRB 060418
  68. GRB(?)060421:MASTER optical limit
  69. GRB(?)060421 : XRT position
  70. Possible GRB060421: BART limits
  71. GRB(?) 060421: Swift detection of a burst
  72. GRB060418: Swift/UVOT Observations
  73. GRB 060418: FRAM early afterglow observation
  74. GRB 060418: Refined Analysis of the Swift-BAT burst
  75. VLT/UVES observations of GRB060418
  76. GRB060418: Swift XRT Team Refined Analysis
  77. GRB060418: Magellan/MIKE Spectroscopic Redshift
  78. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  79. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  80. GRB060413: Swift/UVOT upper limits
  81. SGR 1900+14: Swift detection of an outburst
  82. GRB 060413: Refined analysis of the Swift-BAT burst
  83. GRB 060413: XRT refined analysis
  84. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  85. GRB 060413: Swift detection of a burst
  86. GRB060403: XRT refined analysis
  87. GRB 060403: Swift/UVOT upper limits
  88. SGR 1900+14: BAT observations
  89. GRB 060403: Refined analysis of the Swift-BAT burst
  90. GRB060403: Swift XRT refined position
  91. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  92. GRB 060403: Swift detection of a burst
  93. GRB060331: Swift/UVOT upper limits
  94. Swift XRT observations of the HETE transient H4043
  95. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  96. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  97. SGR 1900+14: Swift-BAT detection of a bright outburst
  98. GRB 060323 : WIDGET simultaneous optical observations
  99. GRB 060322: Confirmation of Swift XRT afterglow
  100. GRB060323: optical limit

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