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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"

472 results found.

  1. Swift GRB 220305A: Global MASTER-Net observations report
  2. IPN triangulation of GRB 220222A
  3. GCN Circ.draft on GRB 220222A
  4. IPN triangulation of GRB 220219A
  5. IPN triangulation of GRB 220209A
  6. IPN triangulation of GRB 220128A (long)
  7. IPN triangulation of GRB 220124A
  8. IPN triangulation of a bright burst from SGR 1935+2154
  9. IPN triangulation of GRB 211226A
  10. IPN triangulation of GRB 211219A
  11. IPN triangulation of GRB 211204C
  12. IPN triangulation of GRB 211120A
  13. GRB 211106A: Swift-XRT observations
  14. IPN triangulation of GRB 211022A
  15. IPN Triangulation of GRB 211019A
  16. IPN Triangulation of GRB 210927B
  17. IceCube-210922A: DESI Observations
  18. IPN triangulation of GRB 210925B
  19. GRB 210919A: Swift/UVOT Upper Limits
  20. Fermi trigger No 652927551: Global MASTER-Net observations report
  21. GRB 210723A: Swift/UVOT Upper Limits
  22. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  23. IPN triangulation of GRB 210606B
  24. IPN triangulation of GRB 210524A
  25. IPN triangulation of GRB 210518A
  26. IPN triangulation of GRB 210511B
  27. IPN triangulation of GRB 210427A
  28. IPN triangulation of GRB 210424B (short/hard)
  29. GRB 210420B: follow-up photometry of optical afterglow at INASAN/Simeiz
  30. Fermi trigger No 639093861: Global MASTER-Net observations report
  31. IPN triangulation of GRB 210324C
  32. IPN triangulation of GRB 210204A
  33. IPN triangulation of GRB 210124B (short)
  34. IPN triangulation of GRB 210121A
  35. IPN triangulation of GRB 201218A
  36. IPN triangulation of GRB 201207A
  37. Konus-Wind observation of GRB 201109A
  38. IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
  39. IPN triangulation of GRB 200907A (short)
  40. IPN triangulation of GRB 200903E
  41. IPN triangulation of GRB 200826B
  42. IPN triangulation of GRB 200826A (short/bright)
  43. IPN triangulation of GRB 200815A (short)
  44. IPN triangulation of GRB 200716A
  45. IPN triangulation of GRB 200605A (short)
  46. Baksan Neutrino Observatory Alert 200511.76: Global MASTER-Net observations report
  47. IPN triangulation of a bright burst from SGR 1935+2154 on 2020-05-10 at 06:12 UT
  48. IPN triangulation of GRB 200422A (long/very bright)
  49. IPN Triangulation of a bright burst from SGR 1935+2154
  50. Improved IPN error box for GRB 200415A (consistent with the Sculptor Galaxy)
  51. IPN triangulation of GRB 200415A (possible Magnetar Giant Flare in Sculptor Galaxy?)
  52. IPN triangulation of GRB 200412A
  53. IPN triangulation of GRB 200325A (short)
  54. Fermi trigger No 606840801: Global MASTER-Net observations report
  55. IPN triangulation of GRB 200313A
  56. GRB 200131A: Swift-XRT refined Analysis
  57. IPN triangulation of GRB 200130B
  58. IPN Triangulation of GRB 200120A
  59. IPN triangulation of GRB 200111A
  60. IPN triangulation of GRB 200101A
  61. IPN triangulation of GRB 191227B (short)
  62. IPN triangulation of GRB 191027A
  63. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  64. IPN triangulation of GRB 190928A (long/bright)
  65. IPN triangulation of GRB 190906A (short)
  66. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  67. IPN triangulation of GRB 190805B
  68. IPN triangulation of GRB 190810A (short)
  69. IPN Triangulation of GRB 190731A
  70. IPN triangulation of GRB 190720A
  71. IPN Triangulation of GRB 190611B
  72. IPN Triangulation of GRB 190501A (long/bright)
  73. LIGO/Virgo S190425z: Lulin Follow-Up Observations
  74. IPN Triangulation of GRB 190329A (long/bright)
  75. IPN Triangulation of GRB 190304A (long)
  76. Improved IPN error box for GRB 190129B
  77. IPN Triangulation of GRB 190129B (long/extremely bright)
  78. IPN Triangulation of GRB 190117A (long)
  79. IPN triangulation of GRB 190103A (long)
  80. IPN Triangulation of GRB 181227A (long)
  81. IPN Triangulation of GRB 181212A (long)
  82. IPN Triangulation of GRB 181028A (long)
  83. IPN Triangulation of GRB 181011A (long)
  84. IPN Triangulation of GRB 180914A (long)
  85. Konus-Wind of the very bright GRB 180914B
  86. GRB 180818B: Enhanced Swift-XRT position
  87. GRB180809B TUG T60 observations
  88. IPN Triangulation of GRB 180703A
  89. IPN Triangulation of GRB 180703B
  90. IPN Triangulation of GRB 180626B (short)
  91. IPN Triangulation of GRB 180611A (long)
  92. IPN Triangulation of GRB 180605A (long)
  93. IPN Triangulation of GRB 180529A (short/hard)
  94. IPN Triangulation of GRB 180526A (long)
  95. IPN Triangulation of GRB 180523A
  96. IPN Triangulation of GRB 180427A
  97. IPN Triangulation of GRB 180409A
  98. IPN Triangulation of GRB 180404C (long)
  99. IPN Triangulation of GRB 180326A (long)
  100. IPN Triangulation of GRB 180318A (long)

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