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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"

4258 results found.

  1. GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
  2. GRB 210927B: GECAM detection
  3. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  4. Fermi GRB 210929B: Global MASTER-Net observations report
  5. GRB 210929B: Fermi GBM Final Real-time Localization
  6. GRB 210929A: Fermi GBM Final Real-time Localization
  7. IPN triangulation of GRB 210925B
  8. GRB 210926A: GECAM detection
  9. GRB 210925A: GECAM detection
  10. GRB 210923B: GECAM detection
  11. GECAM observations of a series of bursts from SGR J1935+2154 (2021-09-15T14 to 2021-09-23T14)
  12. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 September 22
  13. IceCube Alert 210922.76: Global MASTER-Net observations report
  14. GRB 210919A: NOT upper limits
  15. Swift GRB 210919A: Global MASTER-Net observations report
  16. GECAM observations of bursts from SGR J1935+2154 (2021-09-13T01 to 2021-09-15T14)
  17. Konus-Wind observation of the recent SGR 1935+2154 activity
  18. GECAM observations of bursts from SGR J1935+2154 (2021-09-12T05 to 2021-09-13T01)
  19. AGILE observations of two bright bursts from SGR 1935+2154
  20. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  21. Fermi trigger No 653151835: Global MASTER-Net observations report
  22. GRB 210912A: Mondy optical afterglow confirmation
  23. Swift GRB 210912A: Global MASTER-Net observations report
  24. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  25. Fermi trigger No 653084584: Global MASTER-Net observations report
  26. Fermi trigger No 653083551: Global MASTER-Net observations report
  27. Fermi trigger No 653066130: Global MASTER-Net observations report
  28. Fermi trigger No 653072474: Global MASTER-Net observations report
  29. Fermi trigger No 653054042: Global MASTER-Net observations report
  30. Fermi trigger No 653022153: Global MASTER-Net observations report
  31. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  32. Konus-Wind detection of the second intermediate flare from SGR 1935+2154
  33. IPN triangulation of a bright burst from SGR 1935+2154
  34. GRB 210909B: GECAM detection
  35. GECAM observations of a series of bursts from SGR J1935+2154
  36. Swift detection of a burst from SGR Swift J1555.2-5402
  37. GECAM observation of a burst from SGR J1935+2154
  38. GECAM observation of a burst from SGR J1935+2154
  39. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  40. Fermi trigger No 652911693: Global MASTER-Net observations report
  41. Fermi trigger No 652906639: Global MASTER-Net observations report
  42. GECAM observation of a burst from SGR J1555.2-5402
  43. Fermi GBM trigger 652585475 / 210906073 is not a GRB
  44. Fermi trigger No 652585475: Global MASTER-Net observations report
  45. GRB 210827B: GECAM detection
  46. Fermi GBM observation of a burst from SGR J1555.2-5402
  47. Integral GRB210829.17: Global MASTER-Net observations report
  48. Integral GRB210829.14: Global MASTER-Net observations report
  49. Fermi GRB 210827A: Global MASTER-Net observations report
  50. POLAR detection of a SGR-like burst
  51. GRB 210824A: MITSuME Akeno optical upper limits
  52. Swift detection of an outburst from SGR Swift J1555.2-5402
  53. GRB 210822A: GECAM refined analysis
  54. Konus-Wind detection of GRB 210822A
  55. Fermi GRB 210822B: Global MASTER-Net observations report
  56. GRB 210822A: Nanshan/NEXT optical observations
  57. GRB 210822A: GECAM detection
  58. GRB 210820A: LT optical upper limit
  59. Fermi GRB 210813A: Global MASTER-Net observations report
  60. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  61. Fermi GRB 210807C: Global MASTER-Net observations report
  62. Fermi trigger No 650046564: Global MASTER-Net observations report
  63. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  64. IPN Triangulation of a bright burst from SGR 1935+2154
  65. Fermi trigger No 649814537: Global MASTER-Net observations report
  66. Fermi trigger No 649684549: Global MASTER-Net observations report
  67. Swift GRB210731.62: Global MASTER-Net observations report
  68. GRB 210731A: MeerLICHT optical afterglow detection
  69. GRB 210730A: Campo Imperatore optical observations
  70. GRB 210726A: Chandra detection of the X-ray afterglow
  71. GRB 210730A: Swift detection of a burst near M82
  72. Fermi trigger No 648959581: Global MASTER-Net observations report
  73. Fermi trigger No 648868114: Global MASTER-Net observations report
  74. Fermi trigger No 648602917: Global MASTER-Net observations report
  75. GRB 210719A: GECAM detection
  76. IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  77. GECAM detection of a short burst from SGR J1935+2154
  78. Recent activity of SGR 1935+2154 as observed by CGBM
  79. Fermi trigger No 647805873: Global MASTER-Net observations report
  80. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 10
  81. GECAM detection of a short burst from SGR J1935+2154
  82. Fermi trigger No 647641569: Global MASTER-Net observations report
  83. Fermi trigger No 647624281: Global MASTER-Net observations report
  84. GECAM detection of a short burst from SGR J1935+2154
  85. GECAM detection of a short burst from SGR 1935+2154
  86. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 7
  87. GECAM detection of a short burst from SGR 1935+2154
  88. Fermi trigger No 647365516: Global MASTER-Net observations report
  89. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 6
  90. Fermi GBM Observations of SGR J1935+2154
  91. Swift-BAT detection of a burst from SGR 1935+2154
  92. GECAM detection of a bright short burst from SGR 1935+2154
  93. Integral GRB210707.02: Global MASTER-Net observations report
  94. INTEGRAL detection of a burst from SGR 1935+2154
  95. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  96. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  97. GRB 210627B: GECAM detection
  98. IceCube Alert 210629.76: Global MASTER-Net observations report
  99. IceCube-210629A - IceCube observation of a high-energy neutrino candidate track-like event
  100. Fermi trigger No 646443989: Global MASTER-Net observations report

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