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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"

42185 results found.

  1. GRB 051221: No variability in Gemini data
  2. GRB 051221: Gemini observations
  3. GRB 051221: Improved astrometry of the IR counterpart
  4. GRB051221: K-band source
  5. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  6. GRB 051221: IR Observations at GRB+1hr
  7. GRB 051221: Swift detection of a bright short burst
  8. Refined analysis of the SWIFT J1626.6-5156
  9. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  10. GRB051211A (=H3979): Refined Analysis
  11. GRB 051211B: optical afterglow
  12. Swift detection of an RS CVn flare star
  13. GRB051211A: possible optical candidate
  14. GRB 051215: near-infrared observations
  15. GRB051215 - SDSS pre-burst observations
  16. GRB 051215: Swift detection of a possible burst
  17. GRB 051215: A short GRB in a cluster?
  18. GRB051211B: Probable radio afterglow
  19. GRB051105: optical observations
  20. GRB 051213: Swift-BAT refined analysis
  21. GRB051211B: XRT refined analysis
  22. GRB 051211B, optical observation
  23. GRB 051213: Swift-BAT detection of a burst
  24. GRB 051211a: RTT150 optical observations
  25. GRB051211B, RBO optical observations
  26. GRB 051211A: Swift/UVOT upper limits
  27. GRB 051211A,optical observation
  28. GRB 051211B: Swift XRT confirmation of the afterglow
  29. GRB051211B: Liverpool Telescope observation
  30. GRB 051211b: RTT150 optical observations
  31. GRB051211b: P60 Observations
  32. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  33. GRB 051211B: Swift XRT Observations
  34. GRB 051210: Magellan Imaging
  35. GRB 051211: TAROT optical limits
  36. GRB 051211B: a possible optical detection by TAROT
  37. GRB 051211B: a long GRB detected by INTEGRAL
  38. GRB 051211: Swift XRT upper limit
  39. GRB 051211:IAC80 optical observations
  40. HETE SXC localization of GRB 051211 (=H3979)
  41. GRB 051210: Optical imaging from Las Campanas
  42. GRB 051210: SALT detection limit
  43. GRB 051210: BAT further refined analysis of the short burst
  44. GRB 051210: Swift XRT refined analysis
  45. GRB 051210: FRAM early limit
  46. GRB051210: Swift UVOT Observation
  47. GRB 051210: A short GRB in a cluster?
  48. GRB 051210: Swift detection of a burst
  49. IPN observations of SGR1806-20
  50. An extraordinary long burst on December 3 from SGR1806-20
  51. Possible resuming of the SGR 1806-20 activity
  52. GRB051117B: optical observation
  53. GRB051111: optical observaion
  54. GRB 051127: Swift-BAT detection of a possible burst
  55. GRB051117B: Swift XRT refined analysis
  56. GRB051117b: No Swift/UVOT Detection
  57. GRB051111: Rc optical observations: correction
  58. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  59. GRB 051117A: Swift/UVOT Detection of an Afterglow
  60. GRB051111: Suzaku WAM observation of the prompt emission
  61. GRB051111: Rc optical observations
  62. GRB051008: Suzaku WAM observation of the prompt emission
  63. GRB 051109B: GAO 150cm telescope Optical limit
  64. GRB 051109A : GAO 150cm telescope Rc-band detection
  65. GRB 051021 Optical Observations
  66. GRB 051117B: MARGE Optical Limits
  67. GRB 051117A and B: Radio Observations
  68. GRB 051117B: R and I observations of possible host galaxy
  69. GRB 051117b: NIR observations
  70. GRB 051117A: Refined analysis of the Swift-BAT burst
  71. GRB 051117B: Refined analysis of the Swift-BAT burst
  72. GRB051117A : XRT refined analysis
  73. GRB 051117B,optical observation
  74. GRB 051117B: Lulin R and I band observation
  75. GRB 051117B: Optical observations
  76. GRB 051117B: ROTSE-III Optical Limits
  77. GRB051117B: Swift XRT position
  78. GRB 051117B: Swift detection of a burst
  79. GRB 051117: Swift detection of a bright burst
  80. GRB 051028 Optical Observations
  81. GRB 051109B : Nainital upper limits
  82. GRB 051114: Radio Observations
  83. GRB050925: analysis of the XMM-Newton observation
  84. GRB051109A optical observations
  85. GRB 051114: Swift-BAT detection of a short burst
  86. GRB 051111: Further spectroscopic analysis
  87. GRB 051111: Radio afterglow
  88. GRB 051113: Swift-BAT detection of a burst
  89. GRB 051111: AEOS optical observations
  90. GRB051103: Radio Observations
  91. GRB 051109A Milagro GeV/TeV Observations
  92. GRB/SGR 050925: XMM-Newton ToO observation
  93. GRB051111: Swift/UVOT Observations
  94. GRB 051111A : R-band temporal decay index based on Lulin
  95. GRB051111: XRT preliminary analysis
  96. GRB 051111: Swift-BAT refined analysis
  97. GRB 051109A Optical Observations
  98. GRB 051111A : Lulin BVRI multi band afterglow observation
  99. GRB051111a: SARA Observations
  100. GRB 051111a: IR photometry

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