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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"

19353 results found.

  1. GRB 050824: ROTSE-III Optical Limits
  2. GRB050824: Swift-BAT detection of a burst
  3. GRB050822: Swift/UVOT upper limits
  4. GRB 050820A BAT observations of second, larger episode of emission
  5. GRB 050822: Swift-BAT refined analysis
  6. GRB 050820a - corrections to GCN 3846
  7. Swift/UVOT UV Photometry of GRB 050820B
  8. GRB 050822: ROTSE-III Prompt Optical Limits
  9. GRB 050822: Swift detection of a long burst
  10. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  11. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  12. GRB050820a BVRcIc field photometry
  13. GRB050820B XMM-Newton observation
  14. GRB 050820a: NIR Observations by WIRO
  15. GRB 050820B: Swift XRT position
  16. GRB050820B: Refined analysis of the Swift-BAT burst
  17. GRB050820B: BAT-Swift detection of a bright GRB
  18. Swift/UVOT photometry of GRB050820
  19. GRB050820: refined XRT analysis
  20. GRB 050820: Early RAPTOR detections
  21. GRB 050820 Swift-BAT refined analysis
  22. GRB050819: refined XRT analysis
  23. GRB 050820: Swift detection of a GRB
  24. GRB050820: Optical afterglow from P60
  25. GRB 050819 Swift-BAT refined analysis
  26. GRB050819: Swift XRT position
  27. GRB050819: Swift-BAT detection of a weak burst
  28. Swift-BAT trigger 150993 is not a GRB
  29. Swift Trigger 150823 is HETE J1900.1-2455
  30. GRB050817: Swift-BAT Detection of a burst
  31. GRB050815: Optical afterglow detection by Swift UVOT
  32. GRB050815: XRT refined analysis
  33. GRB050815: Refined analysis of the Swift-BAT burst
  34. GRB 050815: ROTSE-III Optical Limits
  35. GRB050815: Swift XRT afterglow localization
  36. GRB050815: Swift-BAT detection of a burst
  37. GRB050814: P60 Optical Afterglow Candidate
  38. GRB 050814: XRT refined analysis
  39. GRB050814: SWIFT/UVOT observation
  40. GRB050814: Refined analysis of the Swift-BAT burst
  41. GRB 050814: Swift XRT Afterglow Localization
  42. GRB 050814: Swift detection of a burst
  43. GRB050813, SDSS pre-burst observations
  44. GRB 050813: KAIT optical limit
  45. GRB 050813: Swift-BAT refined analysis
  46. GRB050813: SWIFT/UVOT observation
  47. GRB 050813: Swift XRT afterglow localization
  48. GRB 050813: Possible Short Swift-BAT GRB
  49. GRB050813 (Swift 150139): P60 Observations
  50. Swift-BAT trigger 150131 is not a GRB
  51. GRB050805b: CrAO optical limit
  52. GRB050805a : Null detection report
  53. Swift-BAT trigger 149118 is very likely not a GRB
  54. Retraction of Swift Trigger 149131 (GRB 050805B)
  55. GRB 050805b: OHP optical limits
  56. GRB 050805b: TAROT optical limits
  57. GRB050805b: MASTER optical observations
  58. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  59. GRB050805a: MASTER optical candidat
  60. Swift-BAT trigger 149118 is probably not a GRB
  61. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  62. GRB 050803: Swift-BAT refined analysis
  63. GRB050803: MASTER further analys
  64. GRB 050803: early Swift XRT analysis results
  65. GRB 050803: TAROT optical limits
  66. GRB050803: MASTER optical observations
  67. GRB050803: Swift-BAT detection of a very long burst
  68. GCN GRB observation 050713A
  69. GRB 050802: Swift/UVOT optical and UV detections
  70. GRB050802 radio non-detection
  71. GRB 050730: OHP optical observations
  72. GRB 050802: early Swift XRT analysis results
  73. GRB 050802: Swift/UVOT observations
  74. GRB 050802: Swift-BAT refined analysis
  75. GRB 050802: XRT position
  76. GRB 050802: Swift Gamma-ray Burst
  77. GRB050801: Swift/UVOT Optical and UV detections
  78. GCN 050801: early Swift XRT analysis results
  79. GRB 050801: Swift-BAT refined analysis
  80. GRB 050801, afterglow observations
  81. GRB 050730, corrected photometry and break?
  82. GRB 050801: ROTSE-III Early Afterglow Break
  83. GRB050801: Swift-BAT detection of a burst
  84. GRB050801: GCN XRT position is incorrect
  85. GRB 050801: ROTSE-III Detection of Possible Counterpart
  86. GRB 050730: XRT refined analysis
  87. GRB 050730: early TAROT optical observations
  88. Swift/UVOT photometry of GRB050730
  89. GRB050730: Refined BAT analysis of the Swift-BAT burst
  90. GRB 050730: Swift XRT afterglow observations
  91. GRB 050730 XMM-Newton observation
  92. GRB050730, afterglow observations
  93. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  94. GRB050730: Liverpool Telescope optical observations
  95. GRB 050730, optical candidate
  96. GRB050730: Swift-BAT detection of a weak burst
  97. GRB 050713A: Swift XRT extended light curve
  98. GRB050726: Swift UVOT observations
  99. GRB 050724: Chandra Observations of the X-ray Afterglow
  100. GRB050713: analysis of the XMM-Newton observation

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