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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"

27415 results found.

  1. Swift-BAT trigger 152038 is definitely not a GRB
  2. GRB050824: CORRECTION to UVOT observing times
  3. Swift-BAT trigger 152038 is probably not a GRB
  4. GRB050824: Swift/UVOT detection of fading afterglow
  5. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  6. GRB 050824: XRT refined analysis and possible afterglow detection
  7. GRB 050824: BAT refined analysis of a soft weak burst
  8. GRB050824: MASTER:OT decay
  9. GRB050824: MASTER observation OT
  10. GRB050805a: MASTER optical candidat
  11. GRB 050824: ROTSE-III Optical Limits
  12. GRB050824: Swift-BAT detection of a burst
  13. GRB050820A: RTT150 optical observations
  14. VLT/UVES spectroscopy of GRB050820
  15. GRB050822: Swift/UVOT upper limits
  16. GRB 050820A BAT observations of second, larger episode of emission
  17. GRB 050822: Swift-BAT refined analysis
  18. GRB 050820a - corrections to GCN 3846
  19. Swift/UVOT UV Photometry of GRB 050820B
  20. GRB 050822: ROTSE-III Prompt Optical Limits
  21. GRB 050822: Swift detection of a long burst
  22. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  23. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  24. GRB 050820a: NIR Observations by WIRO
  25. GRB 050820B: Swift XRT position
  26. GRB050820B: Refined analysis of the Swift-BAT burst
  27. GRB050820B: BAT-Swift detection of a bright GRB
  28. Swift/UVOT photometry of GRB050820
  29. GRB050820: refined XRT analysis
  30. GRB 050820: Early RAPTOR detections
  31. GRB 050820 Swift-BAT refined analysis
  32. GRB050819: refined XRT analysis
  33. GRB 050820: Swift detection of a GRB
  34. GRB050820: Optical afterglow from P60
  35. GRB 050819 Swift-BAT refined analysis
  36. GRB050819: Swift XRT position
  37. GRB050819: Swift-BAT detection of a weak burst
  38. Swift-BAT trigger 150993 is not a GRB
  39. Swift Trigger 150823 is HETE J1900.1-2455
  40. GRB050817: Swift-BAT Detection of a burst
  41. GRB050815: Optical afterglow detection by Swift UVOT
  42. GRB050815: XRT refined analysis
  43. GRB050815: Refined analysis of the Swift-BAT burst
  44. GRB 050815: ROTSE-III Optical Limits
  45. GRB050815: Swift XRT afterglow localization
  46. GRB050815: Swift-BAT detection of a burst
  47. GRB 050814: XRT refined analysis
  48. GRB050814: SWIFT/UVOT observation
  49. GRB050814: Refined analysis of the Swift-BAT burst
  50. GRB 050814: Swift XRT Afterglow Localization
  51. GRB 050814: Swift detection of a burst
  52. GRB050813, SDSS pre-burst observations
  53. GRB 050813: KAIT optical limit
  54. GRB 050813: Swift-BAT refined analysis
  55. GRB050813: SWIFT/UVOT observation
  56. RBO GRB 050714A and GRB 050716 observations
  57. GRB 050813: Possible Short Swift-BAT GRB
  58. GRB050813 (Swift 150139): P60 Observations
  59. Swift-BAT trigger 150131 is not a GRB
  60. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  61. Detection of an intermediate burst from SGR 1806-20 on August 8
  62. GRB 050807: ROTSE-III Optical Limits
  63. GRB050805b: CrAO optical limit
  64. GRB050805a : Null detection report
  65. Swift-BAT trigger 149118 is very likely not a GRB
  66. Retraction of Swift Trigger 149131 (GRB 050805B)
  67. GRB 050805b: OHP optical limits
  68. GRB 050805b: TAROT optical limits
  69. GRB050805b: MASTER optical observations
  70. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  71. GRB050805a: MASTER optical candidat
  72. Swift-BAT trigger 149118 is probably not a GRB
  73. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  74. GRB 050803: Swift-BAT refined analysis
  75. GRB050803: MASTER further analys
  76. GRB 050803: early Swift XRT analysis results
  77. GRB 050803: TAROT optical limits
  78. GRB050803: Swift-BAT detection of a very long burst
  79. GCN GRB observation 050713A
  80. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  81. GRB 050802: Swift/UVOT optical and UV detections
  82. GRB050802 radio non-detection
  83. GRB 050802: early Swift XRT analysis results
  84. GRB 050802: Swift/UVOT observations
  85. GRB 050802: Swift-BAT refined analysis
  86. GRB 050802: XRT position
  87. GRB 050802: Swift Gamma-ray Burst
  88. GRB050801: Swift/UVOT Optical and UV detections
  89. GCN 050801: early Swift XRT analysis results
  90. GRB 050801: Swift-BAT refined analysis
  91. GRB 050801: ROTSE-III Early Afterglow Break
  92. GRB050801: Swift-BAT detection of a burst
  93. GRB050801: GCN XRT position is incorrect
  94. GRB 050801: ROTSE-III Detection of Possible Counterpart
  95. GRB 050730: XRT refined analysis
  96. Swift/UVOT photometry of GRB050730
  97. GRB050730: Refined BAT analysis of the Swift-BAT burst
  98. GRB 050730: Swift XRT afterglow observations
  99. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  100. GRB 050730, optical candidate

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