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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').

17499 results found.

  1. GRB 050219b: CORRECTION to refined XRT position
  2. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  3. GRB 050219b: Refined XRT position
  4. GRB 050219b: Swift-BAT detection of a burst
  5. GRB 050219b: CORRECTION: Swift XRT Position
  6. GRB 050219b: Swift XRT Position
  7. GRB 050219a, optical observations
  8. GRB 050219a: Refined XRT position
  9. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  10. GRB 050219: Swift-BAT detection of a burst
  11. GRB050215b: Swift UVOT Detection of Afterglow Emission
  12. GRB 050219: Prompt X-ray position
  13. GRB 050215b: XRT confirmation of IR afterglow candidate
  14. GRB050215b: P60 Optical Observations
  15. GRB 050215b: Swift XRT Source Variability
  16. GRB 050215B: candidate afterglow
  17. GRB 050215b : Lulin follow-up observation
  18. GRB 050215b, BOOTES-2 simultaneous optical observations
  19. GRB 050215B: UKIRT K-band imaging
  20. GRB 050215b: Swift XRT Observations
  21. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  22. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  23. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  24. GRB050215B: ROTSE-III optical observations
  25. GRB050215A: ROTSE-III Optical Observations
  26. short/hard GRB 050202, optical observations
  27. GRB 050128: Radio observations
  28. Further analysis of the short Swift-BAT GRB 050202
  29. GRB 050202: Second epoch radio observations
  30. GRB050202: Radio Observations
  31. GRB 050202: Short burst detected by Swift-BAT
  32. SGR1806-20: Swift-BAT detection of a large normal burst
  33. GRB050128: Faulkes Telescope South observations
  34. GRB050128,optical observations
  35. GRB050126: Updated Swift XRT Position
  36. GRB 050126: Radio Observations
  37. GRB050128 Swift-BAT observations
  38. GRB 050128: Swift XRT prompt afterglow position
  39. GRB 050124: K-band afterglow observations
  40. GRB050126: MASTER optical limit for KECK OT
  41. GRB050126: Burst Parameters Measured by BAT
  42. GRB050126: MASTER optical observations
  43. GRB 050126: Prompt XRT detection and localization
  44. GRB050124: No Swift UVOT Detection of Afterglow Emission
  45. GRB 050117a: Radio Observations
  46. GRB050124,optical observation
  47. GRB050124: Updated Swift XRT Position and Fluxes
  48. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  49. GRB050124: Refined BAT position, spectral and fluence information
  50. GRB050124: Swift-BAT position of a double-peaked burst
  51. GRB050117a: Radio Observations
  52. GRB050117a: Refined analysis
  53. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  54. GRB050117b: Swift-BAT detection of a weak burst
  55. GRB050117: optical observation
  56. GRB 050117, I-band observations
  57. GRB 050117: Optical observation
  58. GRB050117: Refined XRT position
  59. GRB050117: MASTER optical observations
  60. MASTER:GRB050117 SWIFT
  61. GRB050117: Swift-BAT detection of a long multi-peaked burst
  62. GRB050117: Swift XRT Position
  63. SGR1806-20: Swift-BAT observations of two additional bursts
  64. SGR 1806-20, RHESSI observations of the 041227 giant flare
  65. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  66. GRB 041217: Optical observations
  67. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  68. GRB041228: ROTSE-III Optical Observations
  69. GRB041228: Swift-BAT detection of a burst
  70. GRB041219; RXTE ASM Observations
  71. NIR Observations of GRB 041219
  72. GRB041226: ROTSE-III Optical Observations
  73. GRB041226: Swift-BAT detection of a burst
  74. GRB041223: decay of the afterglow
  75. GRB041224: ROTSE-III Optical Observations
  76. GRB 041223: XRT afterglow spectrum and light curve
  77. GRB 041223 Fluence measured by Swift-BAT
  78. GRB041224: Swift-BAT detection of a soft burst
  79. GRB041223: optical and NIR observations with REM
  80. Swift-BAT Time History of GRB041219
  81. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  82. GRB041223: ROTSE-III Optical Observations
  83. GRB041223: Swift-BAT detection of a bright long burst
  84. GRB041220: Swift-BAT burst
  85. GRB 041219 Optical Observations
  86. GRB041219c: Third Burst in One Day from Swift-BAT
  87. GRB041219b: A Swift-BAT burst
  88. Swift-BAT detection of the bright long burst GRB041219
  89. GRB041217: optical limit 30 min after GRB
  90. GRB041217: Optical Observations
  91. GRB041217: NIR and optical observations with REM
  92. GRB041217: P60 Optical Observations
  93. GRB041217: Infrared Observations
  94. GRB041217: The First GRB Located On-Board Swift
  95. GRB040916: Optical observations
  96. GRB040422: optical and NIR observations at the VLT
  97. GRB040223, improved XMM position
  98. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  99. SAX J0840.7+2248 Optical Observations

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