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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"

28068 results found.

  1. GRB 091018: Swift detection of a burst with optical afterglow
  2. GRB 091003: Possible Supernova Component
  3. GRB 091003: Gemini-N redshift of possible host galaxy
  4. GRB 091010: optical obsevation
  5. GRB 091015: RTT150 optical observations
  6. GRB 090726 R band observations
  7. GRB 091010: optical afterglow candidate rejection
  8. GRB 091010: Swift-XRT refined analysis
  9. Radio observation of GRB090927 with ATCA
  10. Radio observation of GRB090926a with ATCA
  11. Radio observation of GRB080916c with ATCA
  12. GRB 091010: Fermi GBM observation
  13. GRB 091010: Faulkes Telescope North observations
  14. GRB 090531A: Skynet/PROMPT Observations
  15. GRB 090530A: Skynet/DSO Detections
  16. GRB 091010: RXTE detection
  17. GRB 091010: Enhanced XRT position
  18. GRB 091010 optical upper limits
  19. Detection of a short GRB 090929A by RT-2 Experiment
  20. GRB 091010: GROND afterglow candidate
  21. GRB 091010: Swift/UVOT Upper Limits
  22. GRB 091010: Swift-XRT position
  23. GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
  24. GRB 090518: Skynet/PROMPT Observations
  25. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  26. GRB 090904A: afterglow confirmation
  27. GRB 090812: Skynet/PROMPT and GORT Observations
  28. GRB 091003: Lick observations and possible SDSS host galaxy
  29. GRB 090926B: Skynet/PROMPT Observations
  30. GRB 091003: WHT ACAM observations
  31. GRB 091003: Swift-XRT confirmation of fading afterglow
  32. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  33. GRB 091003: Skynet/DSO Observations
  34. GRB 091003: UVOT-enhanced XRT position
  35. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  36. GRB 091003: Swift XRT analysis
  37. GRB 091003A: Fermi LAT detection
  38. GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
  39. GRB 091003A: Fermi GBM detection
  40. GRB 090926A: Skynet/PROMPT Observations of Post-Peak Fading
  41. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  42. GRB 090929A: Swift-XRT non-detection
  43. GRB 090929B: Swift-XRT refined analysis
  44. GRB 090929B: Gemini-N upper limits
  45. GRB 090929B: Skynet/DSO Observations
  46. GRB 090929B: Swift/UVOT Observations
  47. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  48. Correction: GRB 090929B: Enhanced Swift-XRT position
  49. GRB 090929: Enhanced Swift-XRT position
  50. GRB 090929B: Swift detection of a burst
  51. GRB 090929A: Fermi GBM detection
  52. GRB090926A: Swift-XRT refined analysis
  53. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  54. GRB 090927: VLT redshift
  55. GRB 090926B: Fermi GBM detection
  56. GRB 090927: Zadko Telescope observations
  57. Swift/UVOT observations of GRB 090927
  58. GRB 090926A: Skynet/PROMPT Continued Observations
  59. GRB 090927: Swift XRT refined analysis
  60. GRB 090927: Enhanced Swift-XRT position
  61. GRB090926B: Swift/UVOT Upper Limits
  62. GRB090926A: Swift/UVOT observations
  63. GRB 090926B: VLT spectroscopy
  64. GRB 090927: Swift/UVOT detection of an optical afterglow
  65. GRB 090927: Swift detection of a short burst
  66. GRB 090926B: optical object in error circle
  67. GRB 090926B: MAXI GSC detection
  68. GRB 090926A: VLT/X-shooter redshift
  69. GRB 090926B: Swift XRT refined analysis
  70. GRB 090926A: Swift/UVOT detection of an optical afterglow
  71. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  72. GRB090926A: UVOT-enhanced XRT position
  73. GRB 090926B: Swift detection of a burst
  74. GRB 090926: Fermi LAT detection
  75. GRB 090926: Fermi GBM detection
  76. GRB 090925: Fermi GBM detection
  77. GRB090904B : IRSF NIR upper limit
  78. GRB 090922A: Fermi GBM detection
  79. Swift returns to normal operations
  80. GRB 090715B: Skynet/PROMPT Detections
  81. GRB 090726: Skynet/GORT Observations
  82. GRB 090916: Swift-XRT upper limit
  83. GRB 090807: Skynet/DSO Observations
  84. GRB 090915: GROND upper limits
  85. GRB 090915: SARA detection of afterglow candidate
  86. GRB 090912: optical observation
  87. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  88. GRB 090702: Skynet/GORT Observations
  89. GRB 090902B: Skynet/PROMPT Observations
  90. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  91. GRB 090916: Swift detection of a short burst
  92. GRB 090915 Swift-BAT detection of a burst in ground analysis
  93. GRB 090827: Confirmation of the X-ray afterglow
  94. GRB 090912: Swift-XRT refined analysis
  95. GRB 090912: Swift/UVOT Upper Limits
  96. GRB 090912 optical upper limit
  97. GRB 090912: Enhanced Swift-XRT position
  98. GRB 090912: Swift detection of a burst
  99. GRB 090910: Fermi GBM detection
  100. GRB 090814A: Skynet/DSO & GORT Observations

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