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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"

24837 results found.

  1. GRB 180904A: SAO RAS optical observations
  2. GRB 180904A: OSN observations
  3. GRB 180904A: Enhanced Swift-XRT position
  4. GRB 180904A: NOT optical observations, candidate host galaxy
  5. GRB 180904A: Swift detection of a burst
  6. GRB 180829A: Swift-XRT observations
  7. GRB 180828A: Swift/UVOT Upper Limits
  8. GRB 180828A: RATIR Optical and NIR Observations
  9. GRB 180828A: Swift-BAT refined analysis
  10. GRB 180829A/MAXI J0406-019: MAXI/GSC detection
  11. GRB 180828A: Swift-XRT refined Analysis
  12. GRB 180828A / Swift J1754.9-2548: Enhanced Swift-XRT position
  13. GRB 180828A: Fermi GBM observation
  14. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  15. GRB 180818B: TSHAO optical upper limit
  16. GRB 180823A, Swift-BAT refined analysis
  17. IPN Triangulation of GRB 180824A (short)
  18. GRB 180823A: Swift/UVOT Upper Limits
  19. GRB 180823A: RATIR Optical and NIR Observations
  20. GRB 180823A: Swift-XRT refined Analysis
  21. GRB 180823A: Enhanced Swift-XRT position
  22. GRB 180823A: Swift detection of a burst
  23. GRB 180821A: VLT observations
  24. GRB 180821A: Swift/UVOT Upper Limits
  25. GRB 180821A: Swift-XRT refined Analysis
  26. GRB 180821A: Enhanced Swift-XRT position
  27. GRB 180818B: 1.5m OSN optical afterglow candidate
  28. GRB 180821A: iTelescope optical afterglow detection
  29. GRB 180821A: Swift detection of a burst
  30. GRB180806A: confirmation of the X-ray afterglow
  31. GRB 180818B: Swift-XRT refined Analysis
  32. GRB 180818B: Swift-BAT refined analysis
  33. GRB 180818A: Swift-BAT refined analysis
  34. GRB 180818B: Fermi GBM observations
  35. GRB 180818B: Swift/UVOT Upper Limits
  36. GRB 180818B: Enhanced Swift-XRT position
  37. GRB 180818A: Swift/UVOT Upper Limits
  38. GRB 180818B: Swift detection of a burst
  39. GRB 180818A: Swift-XRT refined Analysis
  40. GRB 180818A: Enhanced Swift-XRT position
  41. GRB 180818A: Swift detection of a burst
  42. GRB 180728A: discovery of the associated supernova
  43. GRB 180809A: further Swift/XRT observations
  44. Correction: Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  45. GRB 180812A: Swift/UVOT Detection
  46. Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  47. GRB 180812A: Swift-BAT refined analysis
  48. GRB 180812A: Fermi GBM detection
  49. GRB 180812A: Swift-XRT refined Analysis
  50. GRB 180809B: ePESSTO NTT NIR observations
  51. GRB 180812A: COATLI Detection and Light Curve
  52. GRB 180812A: Enhanced Swift-XRT position
  53. GRB 180812A: Swift detection of a burst
  54. GRB180809B TUG T60 observations
  55. MASTER: OT detection during two Fermi GBM triggers (555263883 and 555263883) error boxes inspection in 22.5 mag SDSS galaxy direction
  56. GRB 180809B: Swift-XRT refined Analysis
  57. GRB 180809B: CrAO optical observations
  58. GRB 180809B, Swift-BAT refined analysis
  59. Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
  60. GRB 180809B: Swift/UVOT Detection
  61. GRB 180809A: Fermi GBM observation
  62. Swift Trigger 852625: a possible GRB
  63. GRB 180809B: VLT optical upper limits
  64. GRB180809B: MASTER Triple Independent Automatic OT Detection
  65. GRB 180809B: LCO Sutherland observations
  66. GRB 180809B: GROND Detection of the NIR Afterglow
  67. GRB 180809B: RATIR Optical Observations and Confirmation of Rapid Fading
  68. GRB180809B: MASTER OT observation
  69. GRB 180805B: Teide LCO optical observations
  70. GRB 180809A: iTelescope optical limit
  71. GRB 180809A: Swift-XRT afterglow detection
  72. GRB 180809B: Swift detection of a burst with an optical afterglow
  73. GRB 180809A: MAXI/GSC detection
  74. GRB180806A: correction to Circular 23097
  75. GRB 180806A: Swift-XRT afterglow detection
  76. GRB 180806A/180806.98: RATIR Optical Observations of MASTER OT J004613.05+242014.1
  77. GRB 180806A: Fermi GBM detection
  78. GRB 180806A/180806.94: Refined COATLI Photometry of MASTER OT J004613.05+242014.1
  79. GRB 180806.94: COATLI Detection of MASTER OT J004613.05+242014.1 and Confirmation of Fading
  80. GRB 180805B: ESO/NTT optical observations
  81. GRB 180805B: COATLI Optical Observations
  82. GRB 180805B: GOTO optical limits
  83. GRB 180805B: VLT optical and near-infrared observations
  84. GRB 180805A: Swift-XRT refined Analysis
  85. GRB 180805B: Swift-XRT refined Analysis
  86. GRB 180805B: Swift-BAT refined analysis (short GRB with extended emission)
  87. GRB 180805A: Swift-BAT refined analysis
  88. GRB 180805B: Swift/UVOT Upper Limits
  89. GRB 180805B: Fermi GBM detection
  90. GRB 180805B: Enhanced Swift-XRT position
  91. GRB 180805B: Swift detection of a burst
  92. GRB 180805A: Enhanced Swift-XRT position
  93. GRB 180805A: Swift detection of a burst
  94. GRB 180728A: A long GRB of the X-ray flash (XRF) subclass, expecting supernova appearance
  95. GRB 180728B: MASTER optical observations short GRB IPN error box
  96. GRB 180728A: Swift/UVOT Detection
  97. GRB 180701A/MAXI J2119-045: CALET Gamma-Ray Burst Monitor data search
  98. GRB 180727A: Swift/UVOT Upper Limits
  99. Konus-Wind observation of the bright nearby GRB 180728A
  100. GRB 180715A: CALET CAL gamma-ray analysis

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