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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"

44441 results found.

  1. GRB 081029: REM observations
  2. Radio observation of GRB 080303 with ATCA
  3. Radio observation of GRB 080411 with ATCA
  4. GRB 081029: UVES/VLT Absorption Redshift
  5. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  6. GRB 081029: ROTSE-III Detection of Optical Counterpart
  7. GRB 081029: Swift detection of a burst
  8. GRB 081028: Magellan redshift
  9. GRB 081028B: Fermi GBM detection
  10. GRB 081021: Fermi GBM detection
  11. GRB081028: UVOT detection of a brightening afterglow
  12. Swift UVOT observations of GRB081028
  13. GRB 081028: Swift-XRT refined analysis
  14. GRB 081028, Swift-BAT refined analysis
  15. GRB 081028: Enhanced Swift-XRT position
  16. GRB 081028: TAROT Calern observatory optical observations
  17. GRB 081028: optical observations at the NOT
  18. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  19. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  20. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  21. GRB 081028: Swift detection of a burst
  22. GRB 081025: TLS upper limits
  23. GRB 081024: No radio detection with the VLA
  24. GRB081025: RTT150 optical observations
  25. GRB081024B: P200 Observations
  26. GRB 081024B: Swift-XRT further observations
  27. GRB 081025 BAT refined analysis
  28. Swift UVOT observations of GRB081025
  29. Swift UVOT observations of GRB081024B
  30. Konus-Wind observation of GRB 081025
  31. GRB 081025: Swift-XRT position
  32. GRB 081024B: Swift-XRT observations
  33. GRB 081025: Burst detection from Swift-BAT slew data
  34. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  35. Fermi-LAT observation of GRB 081024B
  36. Swift UVOT observations of GRB 081024
  37. GRB 081024: Swift-XRT refined analysis
  38. GRB 081024, Swift-BAT refined analysis
  39. GRB 081024: Enhanced Swift-XRT position
  40. GRB 081024: Faulkes Telescope North optical observations
  41. GRB 081024: KAIT Optical Limits
  42. GRB 081024: Early Super-LOTIS Observations
  43. GRB 081024A: ROTSE-III Optical Limits
  44. GRB 081024: Swift detection of a burst
  45. GRB 081022, Swift-BAT refined analysis
  46. GRB 081016A: Swift-XRT refined analysis
  47. GRB 081022: Swift detection of a burst
  48. GRB 081012: Swift-XRT Refined Analysis
  49. Swift trigger 332287 is not a GRB
  50. Swift detection of a possible burst (trigger 332287)
  51. GRB 081012 - Enhanced Swift XRT position
  52. GRB 081017, Swift-BAT refined analysis
  53. GRB 081017: REM early observations
  54. GRB 081017: Swift detection of a burst
  55. GRB 081016B, Swift-BAT refined analysis
  56. GRB 081016B: Swift/UVOT Upper Limits
  57. GRB 081011: Swift XRT refined analysis
  58. GRB 081016B: Swift-XRT Team refined Analysis
  59. GRB 081016B: Enhanced Swift-XRT position
  60. GRB 081016B: ROTSE-III Optical Limits
  61. GRB 081016B: Swift detection of a burst
  62. GRB 081011: Enhanced Swift-XRT position
  63. GRB 081016: Swift-XRT candidate afterglow detection
  64. Swift detection of flare on CC Eri
  65. GRB 081016: A long GRB discovered by INTEGRAL
  66. Trigger 331721 Due to Swift startracker loss-of-lock
  67. Detection of flare star Algol in Swift-BAT slew data
  68. GRB 081009: Fermi GBM detection
  69. GRB 081012: GROND upper limits
  70. GRB 081008: Galaxy associated with z=1.967 absorber
  71. Swift-BAT triggered on the flare star Algol
  72. GRB 081012: Fermi GBM detection
  73. GRB 081007 and GRB 081007B: Fermi GBM detection
  74. GRB 080430: optical observations
  75. GRB 081008 optical upper limit
  76. GRB 081012: Observations from NOT
  77. GRB 081012: Swift/UVOT analysis of initial observations
  78. GRB 081012: Swift/XRT detection
  79. GRB 081012, Swift-BAT refined analysis
  80. GRB 081012: ROTSE-III Optical Limits
  81. GRB 081012: Swift detection of a burst
  82. Revised table for GRB 081011 UVOT detections
  83. GRB081011: UVOT detection of an optical afterglow
  84. GRB 081011: Swift/XRT detection
  85. GRB 081011, Swift-BAT refined analysis
  86. GRB 081008, SMARTS optical/IR afterglow observations
  87. GRB 081011: Swift detection of a burst
  88. GRB 081007: Radio Detection
  89. Konus-Wind observation of GRB 081001
  90. GRB 081007: Rapid PROMPT Detections
  91. GRB 081008, Swift-BAT refined analysis
  92. GRB 081008: VLT redshift confirmation
  93. GRB 081008: Swift-XRT Refined Analysis
  94. GRB081008: Swift/UVOT observations
  95. GRB 081008: Enhanced Swift-XRT position
  96. GRB 081008: Gemini-South Absorption Redshiftt
  97. GRB 081008: VLT/FORS2 spectroscopy
  98. GRB 081008: Swift detection of a burst with optical afterglow
  99. GRB 081008: ROTSE-III Detection of Optical Counterpart
  100. GRB081006B: Fermi GBM detection

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