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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').

2808 results found.

  1. Swift-XRT observations of IceCube 201130A
  2. GRB 201128A: Swift-XRT refined Analysis
  3. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  4. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  5. GRB 201116A: Swift-XRT afterglow detection
  6. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  7. Swift-XRT observations of IceCube 201114A
  8. GRB 201104A: Swift-XRT observations
  9. Swift XRT and UVOT detection of ZTF20acozryr/AT2020yxz/GRB201103B
  10. GRB 201015A: Swift-XRT late time observations
  11. GRB 201104B: Swift-XRT refined Analysis
  12. Fermi GRB 201104A: Global MASTER-Net observations report
  13. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  14. GRB 201029A: Swift-XRT refined Analysis
  15. GRB 201027A: Swift-XRT refined Analysis
  16. GRB 201026A: Swift-XRT refined Analysis
  17. GRB201024A: rebrightening after initial steep decline
  18. GRB 201024A: Swift-XRT refined Analysis
  19. GRB 201021C: Swift-XRT refined Analysis
  20. GRB 201020B: Swift-XRT afterglow detection
  21. Swift-XRT observations of IceCube 201021A
  22. GRB 201020A: Swift-XRT refined Analysis
  23. GRB 201017A: Swift-XRT refined Analysis
  24. GRB 201015A: Swift-XRT refined Analysis
  25. GRB 201008A: Swift-XRT afterglow detection
  26. GRB 201014A: Swift-XRT refined Analysis
  27. Swift-BAT trigger 1000255: XRT afterglow detection of GRB 201014A
  28. GRB 201013A: Swift-XRT refined Analysis
  29. GRB 201006A: Chandra upper limit on the X-ray afterglow
  30. GRB 201008A: Swift-XRT observations
  31. IceCube-200926A: Upper limits from Insight-HXMT Observations
  32. Swift-XRT observations of IceCube 201007A
  33. GRB 201006A: Swift-XRT refined Analysis
  34. GRB 201001A: Swift-XRT refined Analysis
  35. Swift-XRT observations of IceCube 200929A
  36. Swift-XRT observations of IceCube 200926A
  37. GRB 200925B: Swift-XRT refined analysis update
  38. GRB 200925B: Swift-XRT refined Analysis
  39. GRB 200922A: Swift-XRT refined Analysis
  40. GRB 200914A: Swift-XRT further observations
  41. Swift-XRT observations of IceCube 200916A
  42. GRB 200917A: Swift-XRT refined Analysis
  43. Swift-XRT observations of IceCube 200911A
  44. GRB 200914A: Swift-XRT observations
  45. GRB 200907B: Swift-XRT refined Analysis
  46. GRB 200906A: LBT near-infrared upper limit
  47. GRB 200906A: Swift-XRT refined Analysis
  48. GRB 200901B: Swift-XRT refined Analysis
  49. GRB 200901A: Swift-XRT refined Analysis
  50. GRB 200901A: Swift-XRT observations
  51. GRB 200829A: Swift-XRT refined Analysis
  52. GRB 200826A: Swift-XRT afterglow detection
  53. Swift Trigger 992444 is due to detector noise
  54. Swift Trigger 992444: a possible GRB 200821A
  55. GRB 200819A: Swift-XRT refined Analysis
  56. Swift Trigger 990358 is due to detector noise
  57. Swift Trigger 989458 is due to detector noise
  58. GRB 200809B: Swift-XRT afterglow detection
  59. GRB 200806A: Swift-XRT refined Analysis
  60. GRB 200803A: Swift-XRT afterglow detection
  61. GRB 200729A: Swift-XRT refined Analysis
  62. GRB 200714E: Swift-XRT afterglow detection
  63. GRB 200716C: Swift-XRT refined analysis correction
  64. GRB 200716C: Swift-XRT refined Analysis
  65. GRB 200715A: Swift-XRT afterglow detection
  66. GRB 200714E: Swift-XRT observations
  67. GRB 200713A: Swift-XRT refined Analysis
  68. GRB 200711A: Swift-XRT refined Analysis
  69. GRB 200709B/HAWC-200907A: Swift-XRT further observations
  70. GRB 200709B: Swift-XRT observations
  71. GRB 200630A: Swift-XRT refined Analysis
  72. GRB 200623A: Swift XRT further observations
  73. GRB 200623A: Swift-XRT observations
  74. Swift-XRT observations of IceCube 200615A
  75. Fermi GRB 200616A: Global MASTER-Net observations report
  76. GRB 200613A: Swift-XRT afterglow detection
  77. GRB 200613A: Fermi-LAT detection
  78. GRB 200612A: Swift-XRT refined Analysis
  79. GRB 200529A: Swift-XRT refined Analysis
  80. GRB 200528A: Swift-XRT refined Analysis
  81. GRB 200528A: Swift/UVOT Upper Limits
  82. GRB 200524A: Swift-XRT afterglow detection
  83. GRB 200522A: Swift-XRT refined Analysis
  84. GRB 200517A: Swift-XRT Confirmation of afterglow
  85. GRB 200519A: Swift-XRT refined Analysis
  86. GRB 200517A: Swift-XRT afterglow detection
  87. GRB 200512A: Swift-XRT refined Analysis
  88. GRB 200509A: Swift-XRT refined Analysis
  89. GRB 200424A: Swift-XRT afterglow detection
  90. SGR 1935+2154 the Insight-HXMT observation plan
  91. GRB 200424A: Swift/UVOT Upper Limits
  92. GRB 200425A: Swift-XRT refined Analysis
  93. GRB 200424A: Swift-XRT observations
  94. GRB 200412B: Swift XRT confirmation of afterglow and UVOT upper limits
  95. GRB 200405B: Further Swift-XRT observations
  96. GRB 200412B: Swift-XRT afterglow detection
  97. GRB 200411A: Swift-XRT refined Analysis
  98. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  99. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  100. GRB 200410A: Swift-XRT refined Analysis

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