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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"

6098 results found.

  1. GRB 181201A: Fermi-LAT detection
  2. GRB 181201A: iTelescope optical afterglow detection
  3. GRB 181201A: Swift-XRT afterglow detection
  4. GRB 181126A: No Ks-band afterglow detection with Keck I
  5. GRB 181126A: Swift-XRT refined Analysis
  6. GRB 181126A: Fermi GBM observation
  7. GRB 181125A: Fermi GBM observation
  8. GRB 181123B: Swift-XRT refined Analysis
  9. GRB 181120A: Fermi GBM observation
  10. GRB 181120A: Fermi-LAT detection
  11. Swift Trigger 872470: further Swift analysis
  12. GRB 181110A: optical observations in Chilescope observatory
  13. GRB 181110A: Swift-XRT refined Analysis
  14. GRB 181103A: Swift-XRT refined Analysis
  15. GRB 181030A: Swift-XRT refined Analysis
  16. GRB 181030A: SAO RAS optical observations
  17. GRB 181028A: Fermi GBM observation
  18. GRB 181028A: Fermi-LAT detection
  19. GRB 181027A: Fermi GBM detection
  20. IceCube-181023A: HAWC follow-up
  21. Fermi-LAT Gamma-ray Observations of IceCube-181023A
  22. GRB 181022A: Swift-XRT refined Analysis
  23. GRB 181023A: Swift-XRT refined Analysis
  24. GRB 181020A: Global MASTER Net OT observations
  25. GRB 181020A: Swift-XRT refined Analysis
  26. GRB 181020A: Fermi GBM detection
  27. GRB 181020A: Fermi-LAT detection
  28. Fermi-LAT Gamma-ray Observations of IceCube-181014A
  29. GRB 181013A: Swift detection of a probable burst
  30. GRB180913A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 558557292)
  31. GRB 181010A: Fermi GBM observation
  32. GRB 181010A: Swift-XRT refined Analysis
  33. GRB 181003A: Swift-XRT afterglow detection
  34. GRB 181002A: Swift-XRT refined Analysis
  35. GRB 180930A: Swift-XRT refined Analysis
  36. GRB 180925A: Swift-XRT refined Analysis
  37. GRB 180924A: Swift-XRT refined Analysis
  38. GRB 180923B: Fermi GBM detection
  39. GRB 180914B: Swift-XRT afterglow detection
  40. GRB 180914B: Fermi-LAT detection
  41. GRB 180914A: Swift-XRT observations
  42. GRB 180914A: Fermi GBM detection
  43. GRB 180914A: Fermi-LAT detection
  44. IceCube-180908A: CALET Gamma-Ray Burst Monitor upper limits
  45. Fermi-LAT Gamma-ray Observations of IceCube-180908A
  46. INTEGRAL observation of IceCube-180908A
  47. IceCube-180908A: HAWC follow-up
  48. GRB 180905A: Swift-XRT refined Analysis
  49. GRB 180904A: Swift-XRT refined Analysis
  50. GRB 180904A: SAO RAS optical observations
  51. GRB 180904A: OSN observations
  52. GRB 180904A: NOT optical observations, candidate host galaxy
  53. GRB 180829A: Swift-XRT observations
  54. GRB 180828A: Swift-XRT refined Analysis
  55. GRB 180828A: Fermi GBM observation
  56. GRB 180823A: Swift-XRT refined Analysis
  57. GRB 180821A: Swift-XRT refined Analysis
  58. GRB180806A: confirmation of the X-ray afterglow
  59. GRB 180818B: Swift-XRT refined Analysis
  60. GRB 180818B: Fermi GBM observations
  61. GRB 180818A: Swift-XRT refined Analysis
  62. LIGO/Virgo GW170817: A steep decline in the radio light curve and prediction for the X-rays
  63. Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
  64. GRB 180812A: Fermi GBM detection
  65. GRB 180812A: Swift-XRT refined Analysis
  66. Konus-Wind observation of GRB 180809B
  67. GRB 180809B: Swift-XRT refined Analysis
  68. GRB 180809B, Swift-BAT refined analysis
  69. Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
  70. GRB 180809A: Fermi GBM observation
  71. GRB 180809A: iTelescope optical limit
  72. GRB 180809A: Swift-XRT afterglow detection
  73. GRB 180806A: NOT optical observations
  74. GRB 180806A: Swift-XRT afterglow detection
  75. GRB 180806A: Fermi GBM detection
  76. GRB 180805A: Swift-XRT refined Analysis
  77. GRB 180805B: Swift-XRT refined Analysis
  78. GRB 180805B: Fermi GBM detection
  79. GRB 180728B: Fermi GBM detection
  80. GRB 180728A: Fermi GBM observation
  81. GRB 180728A: Swift-XRT refined Analysis
  82. GRB 180727A: Swift-XRT refined Analysis
  83. GRB 180727A: Fermi GBM observation
  84. GRB 180723A: Fermi GBM detection
  85. GRB 180722A: Swift-XRT observations
  86. GRB 180718B: Swift-XRT observations
  87. GRB 180718A: Swift-XRT observations
  88. GRB 180720C: Swift-XRT refined Analysis
  89. GRB 180721A: Swift-XRT refined Analysis
  90. GRB 180720C: Fermi GBM observation
  91. GRB 180706A: OSN detection
  92. GRB 180720B: Swift-XRT refined Analysis
  93. GRB 180720B: Fermi GBM observation
  94. GRB 180720B : Fermi-LAT detection
  95. GRB 180720A: Fermi GBM observation
  96. GRB 180718B: Fermi GBM detection
  97. GRB 180718B: Fermi-LAT detection
  98. GRB 180718A: Fermi GBM detection
  99. GRB 180715A: Swift-XRT observations
  100. GRB 180715A: Fermi GBM detection

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