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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"

4169 results found.

  1. GRB 211022A: GECAM detection
  2. Fermi trigger No 656506979: Global MASTER-Net observations report
  3. GRB 211018A: Detection by GRBAlpha
  4. Fermi trigger No 656288898: Global MASTER-Net observations report
  5. Fermi trigger No 655673024: Global MASTER-Net observations report
  6. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  7. Fermi trigger No 655646385: Global MASTER-Net observations report
  8. Fermi Gamma-ray Burst Monitor trigger 211008665/655401471 is not a GRB
  9. Fermi trigger No 655401471: Global MASTER-Net observations report
  10. GECAM observation of a burst from SGR J1555.2-5402
  11. SGR 1935+2154: Swift/BAT-GUANO detection and arcminute localization
  12. GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
  13. GRB 210927B: GECAM detection
  14. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  15. Fermi GRB 210929B: Global MASTER-Net observations report
  16. GRB 210929B: Fermi GBM Final Real-time Localization
  17. GRB 210929A: Fermi GBM Final Real-time Localization
  18. IPN triangulation of GRB 210925B
  19. GRB 210926A: GECAM detection
  20. GRB 210925A: GECAM detection
  21. GRB 210923B: GECAM detection
  22. GECAM observations of a series of bursts from SGR J1935+2154 (2021-09-15T14 to 2021-09-23T14)
  23. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 September 22
  24. IceCube Alert 210922.76: Global MASTER-Net observations report
  25. GRB 210919A: NOT upper limits
  26. Swift GRB 210919A: Global MASTER-Net observations report
  27. GECAM observations of bursts from SGR J1935+2154 (2021-09-13T01 to 2021-09-15T14)
  28. Konus-Wind observation of the recent SGR 1935+2154 activity
  29. GECAM observations of bursts from SGR J1935+2154 (2021-09-12T05 to 2021-09-13T01)
  30. AGILE observations of two bright bursts from SGR 1935+2154
  31. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  32. Fermi trigger No 653151835: Global MASTER-Net observations report
  33. GRB 210912A: Mondy optical afterglow confirmation
  34. Swift GRB 210912A: Global MASTER-Net observations report
  35. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  36. Fermi trigger No 653084584: Global MASTER-Net observations report
  37. Fermi trigger No 653083551: Global MASTER-Net observations report
  38. Fermi trigger No 653066130: Global MASTER-Net observations report
  39. Fermi trigger No 653072474: Global MASTER-Net observations report
  40. Fermi trigger No 653054042: Global MASTER-Net observations report
  41. Fermi trigger No 653022153: Global MASTER-Net observations report
  42. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  43. Konus-Wind detection of the second intermediate flare from SGR 1935+2154
  44. IPN triangulation of a bright burst from SGR 1935+2154
  45. GRB 210909B: GECAM detection
  46. GECAM observations of a series of bursts from SGR J1935+2154
  47. Swift detection of a burst from SGR Swift J1555.2-5402
  48. GECAM observation of a burst from SGR J1935+2154
  49. GECAM observation of a burst from SGR J1935+2154
  50. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  51. Fermi trigger No 652911693: Global MASTER-Net observations report
  52. Fermi trigger No 652906639: Global MASTER-Net observations report
  53. GECAM observation of a burst from SGR J1555.2-5402
  54. Fermi GBM trigger 652585475 / 210906073 is not a GRB
  55. Fermi trigger No 652585475: Global MASTER-Net observations report
  56. GRB 210827B: GECAM detection
  57. Fermi GBM observation of a burst from SGR J1555.2-5402
  58. Integral GRB210829.17: Global MASTER-Net observations report
  59. Integral GRB210829.14: Global MASTER-Net observations report
  60. Fermi GRB 210827A: Global MASTER-Net observations report
  61. POLAR detection of a SGR-like burst
  62. GRB 210824A: MITSuME Akeno optical upper limits
  63. Swift detection of an outburst from SGR Swift J1555.2-5402
  64. GRB 210822A: GECAM refined analysis
  65. Konus-Wind detection of GRB 210822A
  66. Fermi GRB 210822B: Global MASTER-Net observations report
  67. GRB 210822A: Nanshan/NEXT optical observations
  68. GRB 210822A: GECAM detection
  69. GRB 210820A: LT optical upper limit
  70. Fermi GRB 210813A: Global MASTER-Net observations report
  71. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  72. Fermi GRB 210807C: Global MASTER-Net observations report
  73. Fermi trigger No 650046564: Global MASTER-Net observations report
  74. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  75. IPN Triangulation of a bright burst from SGR 1935+2154
  76. Fermi trigger No 649814537: Global MASTER-Net observations report
  77. Fermi trigger No 649684549: Global MASTER-Net observations report
  78. Swift GRB210731.62: Global MASTER-Net observations report
  79. GRB 210731A: MeerLICHT optical afterglow detection
  80. GRB 210730A: Campo Imperatore optical observations
  81. GRB 210726A: Chandra detection of the X-ray afterglow
  82. GRB 210730A: Swift detection of a burst near M82
  83. Fermi trigger No 648959581: Global MASTER-Net observations report
  84. Fermi trigger No 648868114: Global MASTER-Net observations report
  85. Fermi trigger No 648602917: Global MASTER-Net observations report
  86. GRB 210719A: GECAM detection
  87. IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  88. GECAM detection of a short burst from SGR J1935+2154
  89. Recent activity of SGR 1935+2154 as observed by CGBM
  90. Fermi trigger No 647805873: Global MASTER-Net observations report
  91. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 10
  92. GECAM detection of a short burst from SGR J1935+2154
  93. Fermi trigger No 647641569: Global MASTER-Net observations report
  94. Fermi trigger No 647624281: Global MASTER-Net observations report
  95. GECAM detection of a short burst from SGR J1935+2154
  96. GECAM detection of a short burst from SGR 1935+2154
  97. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 7
  98. GECAM detection of a short burst from SGR 1935+2154
  99. Fermi trigger No 647365516: Global MASTER-Net observations report
  100. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 6

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