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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"

28059 results found.

  1. GRB 181030A: SAO RAS optical observations
  2. GRB 181030A: Swift detection of a burst with a possible optical counterpart
  3. GRB 181028A: Fermi GBM observation
  4. GRB 181027A: Fermi GBM detection
  5. GRB 181027A: Swift-BAT refined analysis
  6. IceCube-181023A: HAWC follow-up
  7. IceCube-181023A: MASTER Net optical alert and follow up observations
  8. Fermi-LAT Gamma-ray Observations of IceCube-181023A
  9. GRB 181023A: Swift-BAT refined analysis
  10. GRB 181023A: Swift/UVOT Upper Limits
  11. GRB 181022A: Swift-XRT refined Analysis
  12. GRB 181023A: Swift-XRT refined Analysis
  13. GRB 181022A: GROND upper limits
  14. GRB 181022A: LCO Sutherland observations
  15. GRB 181023A: Enhanced Swift-XRT position
  16. GRB 181022A: Swift/UVOT Upper Limits
  17. GRB 181023A: Swift detection of a burst
  18. GRB 181022A: Swift-BAT refined analysis
  19. GRB 181022A: Swift detection of a burst
  20. GRB 181020A: Swift/UVOT Detection
  21. GRB 181020A: LCO Cerro Tololo observations
  22. GRB 181020A: Swift-BAT refined analysis
  23. GRB 181018A: Insight-HXMT/HE detection
  24. GRB 181017A: Insight-HXMT/HE detection
  25. GRB 181020A: Swift-XRT refined Analysis
  26. GRB 181020A: Fermi GBM detection
  27. GRB 181020A: Enhanced Swift-XRT position
  28. GRB 181020A: Swift detection of a burst with an optical counterpart
  29. FRB 181016: MASTER optical inspection of the Fast Radio Burst error box
  30. GRB 181014A: Insight-HXMT/HE detection
  31. Fermi GBM Observation of IceCube-181014A
  32. GRB 181016A: Swift-BAT refined analysis
  33. GRB 181013A: AbAO optical upper limit
  34. Search for counterparts to IceCube-181014A with IceCube
  35. Fermi-LAT Gamma-ray Observations of IceCube-181014A
  36. GRB 181013A: Swift/UVOT Upper Limits
  37. GRB 181013A: Swift-BAT refined analysis
  38. GRB 181013A: Swift-XRT afterglow detection
  39. GRB 181013A: Swift detection of a probable burst
  40. GRB 181011A: Global MASTER Net optical inspection
  41. GRB 181011A: MAXI/GSC detection
  42. GROND afterglow detection of GRB 181010A
  43. GRB 181008B: Global MASTER Net optical inspection
  44. GRB 181010A: Swift-BAT refined analysis
  45. IPN Triangulation of GRB 181008B (long)
  46. GRB 181010A: Swift/UVOT Detection
  47. GRB 181010A: Swift-XRT refined Analysis
  48. GRB 181008A: Insight-HXMT/HE detection
  49. GRB 181010A: Enhanced Swift-XRT position
  50. GRB 181010A: RATIR Optical and NIR Afterglow Detection
  51. GRB 181010A: LCO Cerro Tololo observations
  52. GRB 181010A: MASTER-Argentina OT detection
  53. GRB 181010A: Swift detection of a burst with an optical counterpart
  54. GRB 181002A: Mondy optical upper limit
  55. GRB 181003A: RATIR Optical and NIR Observations
  56. GRB 181003A: Swift-BAT refined analysis
  57. GRB 181003A: Swift-XRT afterglow detection
  58. GRB 181003A: Swift/UVOT Upper Limits
  59. GRB 180930A: TSHAO optical upper limit
  60. GRB 181002A: Swift-XRT refined Analysis
  61. GRB 181003A: LCO Cerro Tololo observations
  62. GRB 181003A: MASTER optical observation
  63. GRB181002A: GOTO optical limits
  64. GRB 181002A: Swift/UVOT Upper Limits
  65. GRB 181003A: Swift-XRT observations
  66. GRB 181002A: Swift-BAT refined analysis
  67. GRB 181002A: Enhanced Swift-XRT position
  68. GRB 181002A: Swift detection of a burst
  69. GRB 180914B: RTT150 optical observations
  70. GRB 180914B: RTT150 optical observations
  71. GRB 180930A: Swift-BAT refined analysis
  72. GRB 180930A: Swift-XRT refined Analysis
  73. GRB 180930A: NOT optical upper limits
  74. GRB 180930A: Swift/UVOT Upper Limits
  75. GRB 180930A: Enhanced Swift-XRT position
  76. GRB 180930A: Swift detection of a burst
  77. GRB 180924A: Swift/UVOT Upper Limits
  78. GRB 180925A: Insight-HXMT/HE detection
  79. GRB 180925A: Swift/UVOT Detection
  80. GRB 180925A: Swift-BAT refined analysis
  81. GRB 180925A: Swift-XRT refined Analysis
  82. GRB 180925A: Enhanced Swift-XRT position
  83. Konus-Wind observation of GRB 180923A
  84. GRB 180925A: Swift detection of a burst
  85. GRB 180924A: Swift-XRT refined Analysis
  86. GRB 180924A: Swift-BAT refined analysis
  87. GRB 180923B: Fermi GBM detection
  88. GRB 180924A: Enhanced Swift-XRT position
  89. GRB 180924A: Swift detection of a burst
  90. Swift Trigger 863053 is not an astrophysical event
  91. GRB 180923A: MASTER inspection MAXI/GSC error box
  92. GRB 180923A: MAXI/GSC detection
  93. GRB 180914B: DDOTI/OAN Detection and Confirmation of Fading
  94. GRB 180914B: GOTO optical detection
  95. GRB 180914B : continued TSHAO optical observations
  96. GRB 180914B : TSHAO optical observations
  97. GRB 180914B: Continued RATIR Optical and NIR Observations
  98. GRB 180914B: Optical counterpart observation from OAJ
  99. GRB 180914B: RATIR Optical and NIR Observations
  100. GRB 180914B: Swift-XRT afterglow detection

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