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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"

22112 results found.

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

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