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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"

27225 results found.

  1. GRB 090529: Swift-XRT refined analysis
  2. GRB 090528B: Fermi GBM detection
  3. GRB 090528: Fermi GBM detection
  4. GRB 090530: Enhanced Swift-XRT position
  5. Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
  6. GRB 090530: Swift-BAT refined analysis
  7. GRB 090530: PAIRITEL NIR Detections
  8. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  9. GRB 090530: Swift detection of a burst with an optical counterpart
  10. GRB 090529: optical observations
  11. GRB 090529: TLS Afterglow Observations
  12. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  13. GRB 090529: Swift-BAT refined analysis
  14. GRB 090529: Enhanced Swift-XRT position
  15. GRB 090529: Preliminary Swift/UVOT Upper Limit
  16. GRB 090529: Swift detection of a burst
  17. GRB 090520D: Fermi GBM detection
  18. GRB 090520C: Fermi GBM detection
  19. GRB 090520B: Fermi GBM detection
  20. GRB 090522 : Fermi GBM detection
  21. GRB 090524: Fermi GBM detection
  22. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  23. GRB 090513B: Fermi GBM detection
  24. GRB 090518: Fermi GBM detection
  25. GRB 090516C: Fermi GBM detection
  26. GRB 090520 Swift-BAT detection of a burst in ground analysis
  27. GRB 090423: Fermi GBM T90 follow-up analysis results
  28. GRB 090516: Fermi GBM observation
  29. GRB 090516B: Fermi GBM detection
  30. GRB 090519B: Fermi GBM detection
  31. GRB 090519: Swift-XRT refined analysis
  32. GRB 090519: GROND observation
  33. GRB 090519: Swift/UVOT Upper Limits
  34. GRB 090519, Swift-BAT refined analysis
  35. GRB 090519: Enhanced Swift-XRT position
  36. GRB 090519: FARO Chante Perdrix Observatory optical observations
  37. GRB 090519: TAROT Calern observatory optical observations
  38. GRB 090519: Swift detection of a burst
  39. GRB 090511: Fermi GBM Detection
  40. GRB 090514: Fermi GBM detection
  41. GRB 090518: Swift/UVOT Upper Limits
  42. GRB 090518, Swift-BAT refined analysis
  43. GRB 090518B: Fermi GBM detection
  44. GRB 090516, RIMOTS optical upper limits
  45. GRB090513: Fermi GBM detection
  46. GRB090518 : Optical upper limit by MOA-II telescope
  47. GRB 090518: Swift-XRT refined analysis
  48. GRB 090518: Enhanced Swift-XRT position
  49. GRB 090518: Swift detection of a burst
  50. GRB 090515: Swift/BAT spectral lag results
  51. GRB 090516: Swift-BAT refined analysis
  52. GRB 090516: GROND OBSERVATIONS
  53. GRB 090516 - Zadko Telescope observations
  54. GRB 090516: Swift XRT refined analysis
  55. GRB 090516: Swift/UVOT Observations
  56. GRB 090516: Enhanced Swift-XRT position
  57. GRB 090516: Faulkes Telescope South optical afterglow
  58. GRB 090516: Swift detection of a burst
  59. GRB 090515: ROVOR Upper Limit
  60. GRB 090515: MMT/MMIRS NIR Upper Limit
  61. GRB 090515: Swift/UVOT Observations
  62. GRB 090515: Swift-XRT refined analysis
  63. GRB 090515: Enhanced Swift-XRT position
  64. GRB 090509: Fermi GBM observation
  65. GRB 090515: Swift-BAT refined spectral analysis
  66. GRB 090515: Swift-BAT refined analysis
  67. GRB 090509 - Zadko Telescope observations
  68. GRB 090515: Super-LOTIS Upper Limits
  69. GRB 090515: PAIRITEL Upper Limits
  70. GRB 090515: KAIT optical upper limits
  71. GRB 090515: ROTSE-III Optical Limits
  72. GRB 090515: Swift detection of a short burst
  73. GRB 090510: Suzaku WAM observation of the prompt emission
  74. GRB090510: VLT/FORS2 spectroscopic redshift
  75. GRB 090510: GROND observations
  76. GRB 090510: Swift/UVOT host galaxy candidates
  77. GRB 090510: Fermi-LAT follow-up analysis
  78. GRB 090509, further Swift-BAT refined analysis
  79. GRB 090510B: Fermi GBM detection
  80. GRB 090502: Fermi GBM detection
  81. Konus-Wind observation of GRB 090510
  82. AGILE detection of GRB 090510
  83. GRB 090510: UVOT refined analysis
  84. GRB 090510: Swift XRT refined analysis
  85. GRB 090510: Enhanced Swift-XRT position
  86. GRB 090510: NOT afterglow confirmation
  87. GRB 090510: Swift-BAT refined analysis
  88. GRB 090510: Fermi GBM detection
  89. GRB 090509: Swift-BAT refined analysis
  90. Fermi LAT detection of GRB 090510
  91. GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
  92. GRB 090510: Swift detection of a short hard burst
  93. GRB 090408: optical upper limit
  94. GRB 090418A: optical observation
  95. GRB 090509: GROND afterglow candidate
  96. GRB 090509: Swift detection of a burst
  97. GRB 090323: optical observations
  98. GRB 090423: optical limit
  99. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  100. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m

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