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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"

19604 results found.

  1. GRB 071025 Milagro GeV/TeV Observations
  2. Swift UVOT upper limits
  3. GRB 071025: Swift-XRT Team refined analysis
  4. GRB 071025, Swift-BAT refined analysis
  5. GRB 071025: Early Super-LOTIS Observations
  6. GRB 071025: ROTSE-III Refined Analysis
  7. GRB 071025: Swift XRT refined position
  8. GRB 071025: ROTSE-III Detection of Optical Counterpart
  9. GRB 071025: Swift detection of a burst
  10. GRB 071020: BTA spectroscopy
  11. Possible radio detection of GRB 071021 with the VLA
  12. Radio detection of GRB 071020 with the VLA
  13. GRB 071021: optical and NIR observations
  14. GRB 071021, Swift-BAT refined analysis
  15. GRB 071021: Swift-XRT Team refined analysis
  16. Konus-Wind observation of GRB 071020
  17. GRB 071021: Swift detection of a burst
  18. GRB 071020: Swift-XRT refined analysis
  19. GRB 071020, Swift-BAT refined analysis
  20. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  21. GRB071020 - SDSS Pre-burst Observations
  22. GRB 071020: Swift detection of a bright burst
  23. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  24. GRB 071018: Mercator Telescope optical observations
  25. Swift autonomous slewing re-enabled
  26. GRB 071018: Swift-XRT observation
  27. GRB 071017 - Swift XRT observations
  28. VLA radio observation of GRB 071018
  29. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  30. GRB 071018, Swift-BAT refined analysis
  31. GRB 071018?: Swift detection of a possible burst
  32. GRB 071010B: Suzaku WAM observation of the prompt emission
  33. GRB 071013: 3rd TLS Epoch - constraints on variability
  34. GRB 071013: TLS Upper Limit
  35. VLA detection of radio afterglow of GRB 071010B
  36. VLA non-detection of GRB 071011
  37. GRB 071013: Optical observations
  38. GRB 071013, Swift-BAT refined analysis
  39. GRB 071013: Swift detection of a burst
  40. GRB 071010C Swift-BAT detection of a burst
  41. GRB 071011: Swift-XRT refined analysis
  42. VLA non-detection of GRB 071010A
  43. GRB 071011, Optical afterglow
  44. GRB 071011: MARGE Optical Limits
  45. GRB 071011: XRT afterglow detection
  46. GRB 071011, Swift-BAT refined analysis
  47. GRB 071011: Early Super-LOTIS Observations
  48. GRB 071010B: Bright OT confirmed with TLS
  49. GRB 071011: Swift detection of a burst
  50. Optical Observation: GRB 071010
  51. Optical observations: GRB 071010A
  52. Konus-Wind observation of GRB 071010B
  53. GRB071010B: Swift/XRT detection
  54. GRB 071010B, Swift-BAT refined analysis
  55. GRB 071006, Swift-BAT refined analysis
  56. GRB 071010B: Swift detection of a burst
  57. GRB 071010: Swift-XRT observation
  58. GRB 071008, Swift-BAT refined analysis
  59. GRB 071010, Swift-BAT refined analysis
  60. GRB071008: Swift-XRT observation
  61. GRB 071010: TAROT La Silla observatory detection of the afterglow
  62. GRB 071010: Swift detection of a burst
  63. GRB 071006 Swift-BAT detection of a burst
  64. GRB071008: IAC80 observation
  65. GRB 071008: Swift detection of a burst
  66. GRB 071003: XRT refined analysis
  67. GRB070920A: MAGIC telescope GeV observation
  68. Radio detection of GRB 071003 with the VLA
  69. GRB 070810B: further XRT analysis
  70. Konus-Wind observation of GRB 071003
  71. GRB 071003: Swift XRT position
  72. GRB 071003, Swift-BAT refined analysis
  73. GRB 071003: MARGE Observations
  74. GRB 071003 Optical observations
  75. GRB 071003: KAIT optical afterglow observations
  76. GRB 071003: Swift detection of a bright burst
  77. GRB 070714B: host galaxy spectroscopic redshift
  78. GRB 071001: Swift-XRT Team refined analysis
  79. GRB 071001, Swift-BAT refined analysis
  80. Faulkes Telescope South observations of GRB 071001
  81. GRB 071001: Swift detection of a burst
  82. VLA observation of GRB 070923
  83. Disregard the Swift-XRT Notices today
  84. GRB070925: Swift-XRT Afterglow confirmation
  85. GRB070925: Swift-XRT Position
  86. Update on Swift Status
  87. GRB 070920B: ROTSE-III Early Optical Limits
  88. Recent SGR1806-20 Activity
  89. GRB 070923, Swift-BAT refined analysis
  90. GRB 070920B: XRT observations
  91. GRB 070923: Swift detection of a short hard burst
  92. GRB 070917: Suzaku/WAM observation of the prompt emission
  93. GRB 070920B: TAROT La Silla observatory optical observations
  94. GRB 070917: Confirmation of the X-ray afterglow
  95. GRB 070920B, Swift-BAT refined analysis
  96. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  97. GRB 070920B: NOT optical observations
  98. GRB 070920B: Swift detection of a burst
  99. GRB 070920, Swift-BAT refined analysis
  100. GRB 070920: TAROT Calern observatory optical observations

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