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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').
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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"

27779 results found.

  1. GRB 051227: Swift detection of a burst
  2. Konus-Wind observation of GRB 051221A
  3. GRB051221A: Suzaku WAM observation of the prompt emission
  4. GRB051016: analysis of the XMM-Newton observation
  5. GRB 051221A: Detection at 251nm with Swift UVOT
  6. GRB 051221A: Chandra Afterglow Position
  7. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  8. GRB 051221B: ROTSE-III Optical Limits
  9. GRB 051221B: TAROT optical limits
  10. GRB 051221A: WSRT Radio Observations
  11. GRB 051221: Redshift from Gemini
  12. GRB 051221B: Refined analysis of the Swift-BAT burst
  13. Possible GRB 051221B: MDM Optical Detection
  14. GRB 051221A: RAPTOR Fading Counterpart Constraint
  15. GRB 051221B: BOOTES optical observations.
  16. Possible GRB 051221B: Swift XRT position
  17. Swift-BAT detection of a possible burst
  18. GRB 051221: Swift XRT refined analysis
  19. GRB 051221: Swift/UVOT upper limits
  20. GRB 051221: Correction to GCN #4368
  21. GRB 051221: Improved astrometry of the IR counterpart
  22. GRB 051221: XRT position
  23. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  24. GRB 051221: Swift detection of a bright short burst
  25. Refined analysis of the SWIFT J1626.6-5156
  26. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  27. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  28. GRB 051211B: optical afterglow
  29. Swift detection of an RS CVn flare star
  30. Swift Trigger 172767 is not a GRB
  31. GRB 051215: Swift detection of a possible burst
  32. GRB 051215: A short GRB in a cluster?
  33. GRB 051213: Swift-BAT refined analysis
  34. GRB051211B: XRT refined analysis
  35. GRB 051213: Swift-BAT detection of a burst
  36. GRB051211B, RBO optical observations
  37. GRB 051211A: Swift/UVOT upper limits
  38. GRB 051211B: Swift/UVOT upper limits - correction
  39. GRB 051211B: Swift/UVOT upper limits
  40. GRB 051211B: Swift XRT confirmation of the afterglow
  41. GRB051211B: Liverpool Telescope observation
  42. GRB 051211b: RTT150 optical observations
  43. GRB 051211B: Swift XRT Observations
  44. GRB 051210: Swift/UVOT upper limits
  45. GRB 051211B: a possible optical detection by TAROT
  46. GRB 051211: Swift XRT upper limit
  47. GRB 051210: SALT detection limit
  48. GRB 051210: BAT further refined analysis of the short burst
  49. GRB 051210: Swift XRT refined analysis
  50. GRB 051210: Swift-BAT refined analysis of a short burst
  51. GRB051210: Swift UVOT Observation
  52. GRB 051210: Swift detection of a burst
  53. IPN observations of SGR1806-20
  54. Swift XRT positions
  55. An extraordinary long burst on December 3 from SGR1806-20
  56. Swift UVOT Calibration Documentation
  57. Swift-BAT trigger 165579 is not a GRB
  58. GRB 051127: Swift-BAT detection of a possible burst
  59. GRB051117B: Swift XRT refined analysis
  60. GRB051117b: No Swift/UVOT Detection
  61. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  62. GRB 051117A: Swift/UVOT Detection of an Afterglow
  63. GRB051111: Rc optical observations
  64. GRB051008: Suzaku WAM observation of the prompt emission
  65. GRB 051109A : GAO 150cm telescope Rc-band detection
  66. GRB 051117B: MARGE Optical Limits
  67. GRB 051117B: R and I observations of possible host galaxy
  68. GRB 051117A: Refined analysis of the Swift-BAT burst
  69. GRB 051117B: Refined analysis of the Swift-BAT burst
  70. GRB051117A : XRT refined analysis
  71. GRB 051117B,optical observation
  72. GRB 051117B: Lulin R and I band observation
  73. GRB 051117B: Optical observations
  74. GRB 051117B: ROTSE-III Optical Limits
  75. GRB051117B: Swift XRT position
  76. GRB 051117B: Swift detection of a burst
  77. GRB 051117: Swift detection of a bright burst
  78. GRB051114: results of the Swift-XRT observation
  79. GRB 051114: Swift-BAT refined analysis
  80. GRB050925: analysis of the XMM-Newton observation
  81. GRB 051114: Swift-BAT detection of a short burst
  82. GRB 051113: Swift-BAT refined analysis
  83. GRB 051113: Swift-BAT detection of a burst
  84. GRB 051111: AEOS optical observations
  85. GRB 051109A Milagro GeV/TeV Observations
  86. GRB/SGR 050925: XMM-Newton ToO observation
  87. GRB051111: Swift/UVOT Observations
  88. GRB051111: XRT preliminary analysis
  89. GRB 051111: Swift-BAT refined analysis
  90. GRB 051109A Optical Observations
  91. GRB051111a: SARA Observations
  92. GRB 051111A: KAIT optical observations
  93. GRB051111: Super-LOTIS Early Detection
  94. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  95. Faulkes Telescope R-band detection of GRB051111
  96. GRB051111: Swift-BAT detection of a bright burst
  97. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  98. GRB051109A - radio observations
  99. Early RAPTOR measurements of GRB 051109a - the movie.
  100. Konus-Wind observation of GRB 051109A

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