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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.

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

23435 results found.

  1. GRB 051221B: Optical Observations with Kuiper 1.54m
  2. GRB 051227: Likely host galaxy underlying afterglow position
  3. GRB 051227: optical observation
  4. GRB 051227: optical afterglow
  5. GRB 051227: Magellan r'-band Imaging/Astrometry
  6. GRB 051227: refined analysis of VLT images
  7. GRB 051227: P60 Observations
  8. GRB 051227: MDM Observation
  9. GRB 051227: R-band object in the XRT error circle
  10. GRB 051227: XRT refined analysis
  11. GRB051227: SDSS pre-burst observations
  12. GRB 051227, optical observation
  13. GRB 051227: Swift detection of a burst
  14. GRB051117B: optical observation
  15. GRB 051221A: MDM Optical Observations
  16. GRB 051221A: Detection at 251nm with Swift UVOT
  17. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  18. GRB 051221B: ROTSE-III Optical Limits
  19. GRB 051221B: TAROT optical limits
  20. GRB 051221B: Refined analysis of the Swift-BAT burst
  21. GRB 051221B: BOOTES optical observations.
  22. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  23. Swift-BAT detection of a possible burst
  24. GRB 051221: Swift/UVOT upper limits
  25. GRB 051221: Improved astrometry of the IR counterpart
  26. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  27. GRB 051221: Swift detection of a bright short burst
  28. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  29. Swift detection of an RS CVn flare star
  30. GRB051211A: possible optical candidate
  31. GRB 051215: near-infrared observations
  32. GRB051215 - SDSS pre-burst observations
  33. GRB 051215: Swift detection of a possible burst
  34. GRB 051211B, optical observation
  35. GRB 051213: Swift-BAT detection of a burst
  36. GRB 051211A: Swift/UVOT upper limits
  37. GRB 051211B: Swift/UVOT upper limits
  38. GRB 051211A,optical observation
  39. GRB051211B: Liverpool Telescope observation
  40. GRB051211b: P60 Observations
  41. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  42. GRB 051210: Swift/UVOT upper limits
  43. GRB 051210: Magellan Imaging
  44. GRB 051211: TAROT optical limits
  45. GRB 051211B: a possible optical detection by TAROT
  46. GRB 051211: Swift XRT upper limit
  47. GRB 051211:IAC80 optical observations
  48. GRB 051210: SALT detection limit
  49. GRB 051210: BAT further refined analysis of the short burst
  50. GRB 051210: Swift XRT refined analysis
  51. GRB 051210: FRAM early limit
  52. GRB051210: Swift UVOT Observation
  53. GRB 051210: Swift detection of a burst
  54. IPN observations of SGR1806-20
  55. Swift XRT positions
  56. An extraordinary long burst on December 3 from SGR1806-20
  57. Possible resuming of the SGR 1806-20 activity
  58. GRB051117B: optical observation
  59. GRB051111: optical observaion
  60. GRB 051127: Swift-BAT detection of a possible burst
  61. GRB051117B: Swift XRT refined analysis
  62. GRB051117b: No Swift/UVOT Detection
  63. GRB 051117A: Swift/UVOT Detection of an Afterglow
  64. GRB 051109B: GAO 150cm telescope Optical limit
  65. GRB 051117A and B: Radio Observations
  66. GRB 051117B: R and I observations of possible host galaxy
  67. GRB 051117b: NIR observations
  68. GRB 051117B,optical observation
  69. GRB 051117B: Lulin R and I band observation
  70. GRB 051117B: ROTSE-III Optical Limits
  71. GRB 051117B: Swift detection of a burst
  72. GRB 051117: Swift detection of a bright burst
  73. GRB051114: results of the Swift-XRT observation
  74. GRB 051109B : Nainital upper limits
  75. GRB 051114: Radio Observations
  76. GRB050925: analysis of the XMM-Newton observation
  77. GRB 051114: Swift-BAT detection of a short burst
  78. GRB 051111: Further spectroscopic analysis
  79. GRB 051111: Radio afterglow
  80. GRB 051113: Swift-BAT detection of a burst
  81. GRB051103: Radio Observations
  82. GRB 051109A Milagro GeV/TeV Observations
  83. GRB051111: Swift/UVOT Observations
  84. GRB 051109A Optical Observations
  85. GRB 051111a: IR photometry
  86. GRB051111: Swift-BAT detection of a bright burst
  87. GRB 051109B. Radio Observations
  88. GRB 051109A
  89. GRB051109A - radio observations
  90. GRB 051109b: GETS observation
  91. GRB 051109B: ROTSE-III Optical Limits
  92. GRB 051109A: Swift-UVOT Observations
  93. GRB051109B: no UVOT source detected
  94. GRB 051109B : Lulin Optical Observations
  95. GRB 051109B: Super-LOTIS Observations
  96. GRB 051109B Kiso optical follow-up observation
  97. GRB051105B: REM Optical observation
  98. GRB 051109B: Swift detection of a burst
  99. GRB 051109: PROMPT Detections
  100. GRB 051109: Rc and Ic observations

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