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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"

18631 results found.

  1. GRB 050820: Swift detection of a GRB
  2. GRB050820: Optical afterglow from P60
  3. GRB 050819 Swift-BAT refined analysis
  4. GRB050819: Swift XRT position
  5. GRB050819: Swift-BAT detection of a weak burst
  6. Swift-BAT trigger 150993 is not a GRB
  7. Swift Trigger 150823 is HETE J1900.1-2455
  8. GRB050817: Swift-BAT Detection of a burst
  9. GRB050815: Optical afterglow detection by Swift UVOT
  10. GRB050815: XRT refined analysis
  11. GRB050815: Refined analysis of the Swift-BAT burst
  12. GRB 050815: ROTSE-III Optical Limits
  13. GRB050815: Swift XRT afterglow localization
  14. GRB050815: Swift-BAT detection of a burst
  15. GRB050814: P60 Optical Afterglow Candidate
  16. GRB 050814: XRT refined analysis
  17. GRB050814: SWIFT/UVOT observation
  18. GRB050814: Refined analysis of the Swift-BAT burst
  19. GRB 050814: Swift XRT Afterglow Localization
  20. GRB 050814: Swift detection of a burst
  21. GRB050813, SDSS pre-burst observations
  22. GRB 050813: KAIT optical limit
  23. GRB 050813: Swift-BAT refined analysis
  24. GRB050813: SWIFT/UVOT observation
  25. GRB 050813: Swift XRT afterglow localization
  26. GRB 050813: Possible Short Swift-BAT GRB
  27. GRB050813 (Swift 150139): P60 Observations
  28. Swift-BAT trigger 150131 is not a GRB
  29. GRB050805b: CrAO optical limit
  30. GRB050805a : Null detection report
  31. Swift-BAT trigger 149118 is very likely not a GRB
  32. Retraction of Swift Trigger 149131 (GRB 050805B)
  33. GRB 050805b: OHP optical limits
  34. GRB 050805b: TAROT optical limits
  35. GRB050805b: MASTER optical observations
  36. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  37. GRB050805a: MASTER optical candidat
  38. Swift-BAT trigger 149118 is probably not a GRB
  39. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  40. GRB 050803: Swift-BAT refined analysis
  41. GRB050803: MASTER further analys
  42. GRB 050803: early Swift XRT analysis results
  43. GRB 050803: TAROT optical limits
  44. GRB050803: MASTER optical observations
  45. GRB050803: Swift-BAT detection of a very long burst
  46. GCN GRB observation 050713A
  47. GRB 050802: Swift/UVOT optical and UV detections
  48. GRB050802 radio non-detection
  49. GRB 050730: OHP optical observations
  50. GRB 050802: early Swift XRT analysis results
  51. GRB 050802: Swift/UVOT observations
  52. GRB 050802: Swift-BAT refined analysis
  53. GRB 050802: XRT position
  54. GRB 050802: Swift Gamma-ray Burst
  55. GRB050801: Swift/UVOT Optical and UV detections
  56. GCN 050801: early Swift XRT analysis results
  57. GRB 050801: Swift-BAT refined analysis
  58. GRB 050801, afterglow observations
  59. GRB 050730, corrected photometry and break?
  60. GRB 050801: ROTSE-III Early Afterglow Break
  61. GRB050801: Swift-BAT detection of a burst
  62. GRB050801: GCN XRT position is incorrect
  63. GRB 050801: ROTSE-III Detection of Possible Counterpart
  64. GRB 050730: XRT refined analysis
  65. GRB 050730: early TAROT optical observations
  66. Swift/UVOT photometry of GRB050730
  67. GRB050730: Refined BAT analysis of the Swift-BAT burst
  68. GRB 050730: Swift XRT afterglow observations
  69. GRB 050730 XMM-Newton observation
  70. GRB050730, afterglow observations
  71. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  72. GRB050730: Liverpool Telescope optical observations
  73. GRB 050730, optical candidate
  74. GRB050730: Swift-BAT detection of a weak burst
  75. GRB 050713A: Swift XRT extended light curve
  76. GRB050726: Swift UVOT observations
  77. GRB 050724: Chandra Observations of the X-ray Afterglow
  78. GRB050713: analysis of the XMM-Newton observation
  79. Swift-BAT trigger 147918 is not a real GRB
  80. GRB 050727: RTT150 optical observations
  81. GRB050727: KAIT optical limit
  82. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  83. GRB 050726: early Swift XRT analysis results
  84. GRB050726: Swift-BAT detection of a weak burst
  85. GRB 050724: SWIFT XRT refined position
  86. GRB 050724: optical and near-IR observations
  87. GRB 050724: Swift/UVOT Upper Limit
  88. GRB 050724: early Swift XRT analysis results
  89. GRB050724: Refined analysis of the Swift-BAT possible short burst
  90. GRB050724: a short-burst detected by Swift
  91. Swift-BAT trigger 147325 is not due to a real GRB
  92. GRB050723: XRT distributed coordinates are not related to the burst
  93. GRB 050721A: Swift-BAT refined analysis
  94. GRB 050721A: Early Swift XRT analysis results
  95. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  96. GRB 050721a: Optical Observations
  97. GRB050721A: Swift-BAT detection of a weak burst
  98. GRB 050714a: Refined XRT analysis and afterglow confirmation
  99. Swift-BAT trigger 146731 is not a real GRB
  100. Swift-BAT detection of a possible GRB

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