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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

27401 results found.

  1. GRB 050219b: Swift-BAT detection of a burst
  2. GRB 050219b: CORRECTION: Swift XRT Position
  3. GRB 050219b: Swift XRT Position
  4. GRB 050219a, optical observations
  5. GRB 050219a: Refined XRT position
  6. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  7. GRB 050219: Swift-BAT detection of a burst
  8. GRB050215b: Swift UVOT Detection of Afterglow Emission
  9. GRB 050219: Prompt X-ray position
  10. GRB 050215B: candidate afterglow
  11. GRB 050215b : Lulin follow-up observation
  12. GRB 050215b, BOOTES-2 simultaneous optical observations
  13. GRB 050215B: UKIRT K-band imaging
  14. GRB 050215b: Swift XRT Observations
  15. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  16. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  17. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  18. GRB 050215b, BOOTES-1B optical limit
  19. GRB050215B: ROTSE-III optical observations
  20. GRB050215A: ROTSE-III Optical Observations
  21. GRB050209: REM optical observations
  22. GRB 050209 Optical observations
  23. GRB050209: P60 Optical Observations
  24. GRB 050209: Optical observation
  25. Further analysis of the short Swift-BAT GRB 050202
  26. GRB 050202: Second epoch radio observations
  27. GRB050202: Radio Observations
  28. GRB 050202: Short burst detected by Swift-BAT
  29. SGR1806-20: Swift-BAT detection of a large normal burst
  30. GRB050128: Faulkes Telescope South observations
  31. GRB050128,optical observations
  32. GRB050128 Swift-BAT observations
  33. GRB 050128: Swift XRT prompt afterglow position
  34. GRB050126: MASTER optical limit for KECK OT
  35. GRB050126: Burst Parameters Measured by BAT
  36. GRB 050126: Prompt XRT detection and localization
  37. GRB 050124 I-band observation
  38. GRB050124,optical observation
  39. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  40. GRB050124: Refined BAT position, spectral and fluence information
  41. GRB050124: Swift-BAT position of a double-peaked burst
  42. GRB050123,optical observation
  43. GRB 050123: KAIT observations
  44. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  45. GRB050117a: Refined analysis
  46. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  47. GRB050117b: Swift-BAT detection of a weak burst
  48. GRB 050117, I-band observations
  49. GRB050117: Swift-BAT detection of a long multi-peaked burst
  50. GRB050117: Swift XRT Position
  51. SGR1806-20: Swift-BAT observations of two additional bursts
  52. SGR 1806-20, RHESSI observations of the 041227 giant flare
  53. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  54. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  55. The giant outburst from SGR 1806-20
  56. GRB041228: Swift-BAT detection of a burst
  57. GRB041219; RXTE ASM Observations
  58. NIR Observations of GRB 041219
  59. GRB041226: Swift-BAT detection of a burst
  60. GRB 041224: near-infrared observations with REM
  61. GRB 041223 Fluence measured by Swift-BAT
  62. GRB041224: Swift-BAT detection of a soft burst
  63. Swift-BAT Time History of GRB041219
  64. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  65. GRB041223: Swift-BAT detection of a bright long burst
  66. GRB041220: Swift-BAT burst
  67. Deep RAPTOR observations during GRB 041219
  68. GRB041219c: Third Burst in One Day from Swift-BAT
  69. GRB041219b: A Swift-BAT burst
  70. GRB 041219 ,optical observation
  71. GRB 041218: R-band optical observations
  72. Swift-BAT detection of the bright long burst GRB041219
  73. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  74. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  75. GRB041217: The First GRB Located On-Board Swift
  76. GRB041211: RAPTOR observations
  77. GRB041211, BVRcIc field calibration
  78. GRB041211,optical observation
  79. GRB 041211: KAIT observations
  80. Distribution of IBAS Alerts for NON-GRB sources
  81. GRB 041006: GETS Optical Afterglow Observation
  82. Summary of the recent bursts from SGR 1806-20
  83. GRB041015, optical observation in CrAO
  84. Bright bursts from SGR1806-20
  85. GRB 041016: BOOTES-2 simultaneous observation
  86. GRB041016,optical observation
  87. GRB 041016: Optical limits
  88. GRB 041016:Optical limit during first minute
  89. GRB041016: MASTER: Optical observations
  90. GRB041006: Near Infrared observations
  91. GRB 041016: Optical limit
  92. GRB 041015 R band observations
  93. GRB040924, BVRcIc field calibration
  94. GRB041015: MASTER: Optical observations
  95. GRB041015,optical observation
  96. GRB041006: MASTER optical observations
  97. GRB041006,optical observation
  98. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  99. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  100. GRB040929,optical observation

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