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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

23410 results found.

  1. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  2. GRB 051221: Swift detection of a bright short burst
  3. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  4. Swift detection of an RS CVn flare star
  5. GRB051211A: possible optical candidate
  6. GRB 051215: near-infrared observations
  7. GRB051215 - SDSS pre-burst observations
  8. GRB 051215: Swift detection of a possible burst
  9. GRB 051211B, optical observation
  10. GRB 051213: Swift-BAT detection of a burst
  11. GRB 051211A: Swift/UVOT upper limits
  12. GRB 051211B: Swift/UVOT upper limits
  13. GRB 051211A,optical observation
  14. GRB051211B: Liverpool Telescope observation
  15. GRB051211b: P60 Observations
  16. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  17. GRB 051210: Swift/UVOT upper limits
  18. GRB 051210: Magellan Imaging
  19. GRB 051211: TAROT optical limits
  20. GRB 051211B: a possible optical detection by TAROT
  21. GRB 051211: Swift XRT upper limit
  22. GRB 051211:IAC80 optical observations
  23. GRB 051210: SALT detection limit
  24. GRB 051210: BAT further refined analysis of the short burst
  25. GRB 051210: Swift XRT refined analysis
  26. GRB 051210: FRAM early limit
  27. GRB051210: Swift UVOT Observation
  28. GRB 051210: Swift detection of a burst
  29. IPN observations of SGR1806-20
  30. Swift XRT positions
  31. An extraordinary long burst on December 3 from SGR1806-20
  32. Possible resuming of the SGR 1806-20 activity
  33. GRB051117B: optical observation
  34. GRB051111: optical observaion
  35. GRB 051127: Swift-BAT detection of a possible burst
  36. GRB051117B: Swift XRT refined analysis
  37. GRB051117b: No Swift/UVOT Detection
  38. GRB 051117A: Swift/UVOT Detection of an Afterglow
  39. GRB 051109B: GAO 150cm telescope Optical limit
  40. GRB 051117A and B: Radio Observations
  41. GRB 051117B: R and I observations of possible host galaxy
  42. GRB 051117b: NIR observations
  43. GRB 051117B,optical observation
  44. GRB 051117B: Lulin R and I band observation
  45. GRB 051117B: ROTSE-III Optical Limits
  46. GRB 051117B: Swift detection of a burst
  47. GRB 051117: Swift detection of a bright burst
  48. GRB051114: results of the Swift-XRT observation
  49. GRB 051109B : Nainital upper limits
  50. GRB 051114: Radio Observations
  51. GRB050925: analysis of the XMM-Newton observation
  52. GRB 051114: Swift-BAT detection of a short burst
  53. GRB 051111: Further spectroscopic analysis
  54. GRB 051111: Radio afterglow
  55. GRB 051113: Swift-BAT detection of a burst
  56. GRB051103: Radio Observations
  57. GRB 051109A Milagro GeV/TeV Observations
  58. GRB051111: Swift/UVOT Observations
  59. GRB 051109A Optical Observations
  60. GRB 051111a: IR photometry
  61. GRB051111: Swift-BAT detection of a bright burst
  62. GRB 051109B. Radio Observations
  63. GRB 051109A
  64. GRB051109A - radio observations
  65. GRB 051109b: GETS observation
  66. GRB 051109B: ROTSE-III Optical Limits
  67. GRB 051109A: Swift-UVOT Observations
  68. GRB051109B: no UVOT source detected
  69. GRB 051109B : Lulin Optical Observations
  70. GRB 051109B: Super-LOTIS Observations
  71. GRB 051109B Kiso optical follow-up observation
  72. GRB051105B: REM Optical observation
  73. GRB 051109B: Swift detection of a burst
  74. GRB 051109: PROMPT Detections
  75. GRB 051109: Rc and Ic observations
  76. GRB 051109a: IR Photometry and Astrometry
  77. GRB051109: Swift detection of a burst
  78. GRB 051109a: IR Detections
  79. GRB051105B: Swift/XRT upper limit
  80. GRB051105B: Swift/UVOT upper limit
  81. GRB051103: optical observations
  82. GRB 051105a, observation from Naini Tal and OSN
  83. GRB 051105a: MDM Observations
  84. GRB 051105A: TNG optical observations
  85. GRB051105A: Swift/UVOT Observations
  86. GRB 051105A, radio observations
  87. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  88. XRT observations of GRB 051105A
  89. GRB 051105: Optical limit
  90. GRB 051105: Swift detection of a short burst
  91. Recent GRB UBVRcIc field photometry
  92. GRB051028 SARA Observation
  93. GRB051028: Swift/UVOT upper limits
  94. GRB051028: Swift XRT Position
  95. GRB051022: Swift XRT measurement of jet break
  96. GRB051021B: Swift/UVOT Upper limits
  97. GRB 051021, Optical Observations
  98. GRB051012: Swift-XRT analysis
  99. GRB 051022, mm counterpart
  100. GRB 051022: Swift/UVOT Upper Limits

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