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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"

28866 results found.

  1. GRB 061007: Magellan Spectroscopy
  2. GRB 061007: Swift-BAT refined analysis
  3. GRB 061006: Swift/UVOT optical observations
  4. Konus-Wind observation of the short hard GRB 061006
  5. GRB 061007 - FTS early brightening and power law decay
  6. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  7. GRB 061007: Swift detection of a burst with an optical counterpart
  8. GRB 061007: ROTSE-III Detection of Optical Counterpart
  9. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  10. GRB 061006: Swift detection of a burst
  11. GRB061004: Swift/UVOT optical observations
  12. GRB 061004: Swift-XRT Team Refined Analysis
  13. GRB 061004, Swift BAT refined analysis
  14. GRB 061004: Swift detection of a burst
  15. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  16. GRB 060928: Swift observations
  17. GRB 061002: Swift-XRT Team Refined Analysis
  18. GRB061002 - SDSS Pre-Burst Observations
  19. GRB 061002, Swift-BAT refined analysis
  20. GRB061002: MASTER-VWF-Kislovodsk observations
  21. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  22. GRB 061002: Swift detection of a burst
  23. GRB060930: Faulkes Telescope South observation
  24. GRB 060929: Swift/UVOT Optical Observations
  25. GRB 060930: ROTSE-III Optical Limits
  26. GRB060929: Swift-XRT refined analysis.
  27. GRB 060929, Swift-BAT refined analysis
  28. GRB 060929: MASTER-VWF-Kislovodsk observations
  29. Liverpool Telescope observations of GRB 060929
  30. GRB 060929: Swift detection of a burst
  31. GRB 060927: Swift/UVOT Optical Observations
  32. GRB 060927: Early color
  33. GRB 060927: Swift XRT Team refined analysis
  34. GRB 060927, Swift-BAT refined analysis
  35. GRB060927: Faulkes Telescope South observation
  36. GRB060927 - SDSS Pre-Burst Observations
  37. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  38. GRB 060927: Swift detection of a burst
  39. GRB 060926: Swift-UVOT Detections
  40. GRB 060926, Swift-BAT refined analysis
  41. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  42. GRB 060926: Swift detection of a burst
  43. GRB 060923C, Swift-BAT refined analysis
  44. GRB060923B: Swift/UVOT upper limits
  45. GRB 060923C, Swift-BAT partial refined analysis
  46. GRB 060923C: Keck Observations
  47. GRB 060923A: Keck and Gemini Observations
  48. GRB 060923B, Swift-BAT refined analysis
  49. GRB060923C : Faulkes Telescope South optical limits
  50. GRB060923C: Faulkes Telescope North optical observations
  51. GRB 060923C: optical observation
  52. GRB 060923C: Swift detection of a burst
  53. GRB 060923B: Swift detection of a burst
  54. GRB 060923, Swift-BAT refined analysis
  55. GRB 060923: Early Super-LOTIS Observations
  56. GRB060923: Faulkes Telescope North optical observations
  57. GRB 060923: KAIT observations
  58. GRB 060923: Swift detection of a burst
  59. Swift detection of IGR J17497-2821 (trigger 230504)
  60. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  61. GRB 060919, Swift-BAT refined analysis
  62. GRB060919: XRT refined analysis
  63. GRB 060919: TAROT optical observations
  64. GRB 060919: Swift detection of a burst
  65. Konus-Wind observation of GRB 060912
  66. GRB060912: Swift/UVOT Observations
  67. GRB 060912: Swift XRT Team Refined Analysis
  68. GRB 060912, Swift-BAT refined analysis
  69. GRB 060912: Swift detection of a burst with an optical afterglow
  70. GRB 060908, Swift/XRT refined analysis
  71. GRB 060908: Swift/UVOT Observations
  72. GRB 060908: Danish/DFOSC optical observations
  73. GRB 060908, Swift-BAT refined analysis
  74. GRB 060908 - SDSS Pre-burst Observations
  75. GRB 060908: PROMPT Detection of a Bright Counterpart
  76. GRB 060908: Swift detection of a burst with a bright optical counterpart
  77. GRB 060904A: Suzaku/WAM observation of the prompt emission
  78. GRB060904b optical detections (delayed report due to internet outage)
  79. GRB 060906: optical observation
  80. GRB 060906: Early RAPTOR optical limits
  81. GRB 060906, Swift-BAT refined spectral analysis
  82. GRB 060906: Swift/XRT Refined Analysis
  83. GRB 060906: Swift-UVOT observations
  84. GRB 060906, Swift-BAT refined analysis
  85. GRB 060906: KAIT observations
  86. GRB 060906 (?): P60 Optical Afterglow Candidate
  87. GRB 060906: Swift detection of a probable burst
  88. GRB 060904B: RTT150 optical observations
  89. GRB060904A: Swift/UVOT optical observations
  90. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  91. GRB 060904B: Swift-BAT refined analysis
  92. GRB060904b: Optical observations with Swift/UVOT
  93. Konus-Wind observation of GRB 060904A
  94. GRB 060904B: Swift-XRT refined analysis
  95. GRB 060904A: Refined analysis of the Swift-BAT burst
  96. GRB 060904A: Swift-XRT refined analysis
  97. GRB 060904B: Optical observations at Crni Vrh
  98. GRB 060904B: TAROT optical counterpart observations
  99. GRB060904B - SDSS Pre-Burst Observations
  100. GRB 060904: TAROT optical observations

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