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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"

8473 results found.

  1. GRB 100115A: SARA Astrometry
  2. NOT observation of GRB100115A localization
  3. GRB 100115A: SARA Afterglow Candidate
  4. GRB 100115A: Swift/UVOT Upper Limits
  5. GRB 100115A: Swift-XRT candidate afterglow
  6. GRB 100111A: Swift-BAT refined analysis
  7. GRB 100111A: Swift detection of a burst with an optical afterglow
  8. GRB 100103A: Swift/UVOT Upper Limits
  9. GRB 091231: GROND NIR observations
  10. Trigger 381591: Swift detection of a possible burst
  11. GRB 091230: Swift-XRT observation
  12. GRB 091230: GROND optical/NIR afterglow candidate
  13. Trigger 381434: Swift detection of a possible burst
  14. GRB 091221: ROTSE-III Detection of Optical Counterpart
  15. GRB 091221: Swift detection of a burst
  16. Swift trigger 379449 (possible GRB) is not a burst
  17. Trigger 379449: Swift detection of a possible burst
  18. GRB 091208B: Swift detection of a burst with an optical afterglow
  19. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  20. GRB 091117: Chandra Observations
  21. Swift trigger 377436 (possible GRB 091130A) is not a burst
  22. GRB 091130B: Swift detection of a burst
  23. GRB 091130: Swift detection of a possible burst
  24. GRB 091127 : GROND observations
  25. GRB 091127: Swift/UVOT Detection of an Optical Afterglow
  26. GRB 091127: Liverpool Telescope afterglow candidate
  27. GRB091117: Gemini South Observations
  28. GRB 091109B: Swift detection of a short burst
  29. GRB 091109: Faulkes Telescope South observations
  30. GRB 091109: Swift detection of a burst with optical afterglow
  31. GRB 091104: Swift detection of a burst
  32. GRB 091102 : Faulkes Telescope South Upper Limits
  33. GRB 091102: GROND Upper Limits
  34. GRB 091102: Swift/XRT localization
  35. GRB 091102: Swift/UVOT Finding Chart Observation
  36. GRB 091024: optical observations
  37. GRB 091029: Gemini-South Redshift
  38. GRB 091029: Swift detection of a burst with an optical counterpart
  39. GRB 091026: Swift-BAT refined analysis
  40. GRB 091026: Swift detection of a Gamma Ray Burst
  41. GRB 091024: Swift-XRT team refined analysis
  42. GRB 091024: Faulkes Telescope North Afterglow Candidate
  43. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  44. GRB 091020: Swift detection of a burst with an optical afterglow
  45. GRB 091018: miniTAO/ANIR Observations
  46. GRB 091018 : Faulkes Telescope South Observations
  47. GRB 091018: GROND observations
  48. GRB 091018: ROTSE-III Detection of Optical Counterpart
  49. GRB 091018: Swift detection of a burst with optical afterglow
  50. Fwd: GRB 091003: Possible Supernova Component Retraction
  51. GRB 091003: Possible Supernova Component
  52. GRB 091010: optical obsevation
  53. GRB 091010: optical afterglow candidate rejection
  54. GRB 091010: Faulkes Telescope North observations
  55. GRB 091010: RXTE detection
  56. GRB 091010: Enhanced XRT position
  57. GRB 091010 optical upper limits
  58. GRB 091010: GROND afterglow candidate
  59. GRB 090910: SuperAGILE Localization of a Long GRB
  60. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  61. GRB 090929B: Gemini-N upper limits
  62. GRB 090929B: Swift detection of a burst
  63. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  64. GRB 090926B: VLT spectroscopy
  65. GRB 090927: Swift/UVOT detection of an optical afterglow
  66. GRB 090926A: Swift/UVOT detection of an optical afterglow
  67. GRB 090926B: Swift detection of a burst
  68. GRB 090925: Fermi GBM detection
  69. GRB 090915: SARA detection of afterglow candidate
  70. GRB 090912: optical observation
  71. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  72. GRB 090912: Swift detection of a burst
  73. GRB 090904A: Swift-BAT refined analysis
  74. GRB 090902B: WSRT Radio Observation
  75. GRB 090904B: Swift detection of a burst
  76. GRB 090904: Swift detection of a burst
  77. GRB 090902B: Faulkes Telescope North observations
  78. GRB 090902B: Optical afterglow candidate
  79. GRB090902B: Swift/UVOT observations
  80. GRB 090902B: Swift/XRT Afterglow Candidate
  81. GRB 090831C: Swift detection of a burst
  82. GRB 090831B: Swift detection of a possible burst
  83. Konus-Wind observations of GRB 090827
  84. GRB 090817 - TLS Observations
  85. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  86. GRB 090817: Swift-XRT observations
  87. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  88. GRB 090814: Swift detection of a burst
  89. GRB 090813: optical candidate from 1.23m CAHA telescope
  90. GRB 090813: Swift detection of a burst
  91. GRB 090812: Swift detection of a burst with an optical counterpart
  92. GRB 090809: Swift detection of a burst with a possible optical counterpart
  93. GRB 090807: Swift detection of a burst
  94. GRB 090802: Fermi GBM detection
  95. Swift trigger 358760 is probably a noise event
  96. GRB 090709A : Quick look analysis of the Suzaku observation
  97. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  98. GRB 090728: Swift detection of a burst
  99. GRB 090727: Swift-BAT refined analysis
  100. GRB 090727: Liverpool Telescope possible OT candidate

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