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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

5862 results found.

  1. IceCube Alert 211123.60: Global MASTER-Net observations report
  2. Fermi trigger No 659183098: Global MASTER-Net observations report
  3. GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV
  4. Fermi trigger No 658971499: Global MASTER-Net observations report
  5. Fermi trigger No 658755664: Global MASTER-Net observations report
  6. GRB 211115A: MAXI/GSC detection
  7. Fermi GRB 211112A: Global MASTER-Net observations report
  8. Fermi trigger No 658214822: Global MASTER-Net observations report
  9. Fermi GRB 211109B: Global MASTER-Net observations report
  10. Fermi GRB 211109A: Global MASTER-Net observations report
  11. Fermi GRB 211031A: Global MASTER-Net observations report
  12. GRB 211025A: Swift detection of a burst
  13. GECAM detection of a short burst probably from SGR J1555.2-5402
  14. Fermi trigger No 656268212: Global MASTER-Net observations report
  15. Fermi GRB 211019A: Global MASTER-Net observations report
  16. Fermi trigger No 655673024: Global MASTER-Net observations report
  17. IceCube-20210922A: No optical counterparts found by MITSuME observations
  18. Swift GRB211010.45: Global MASTER-Net observations report
  19. GRB 210927B: GECAM detection
  20. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  21. Swift GRB 210930A: Global MASTER-Net observations report
  22. Fermi trigger No 654658271: Global MASTER-Net observations report
  23. Fermi GRB 210929B: Global MASTER-Net observations report
  24. Fermi-LAT Gamma-ray Observations of IceCubeCascade-210926A
  25. GRB 210925B: AstroSat CZTI detection
  26. IPN triangulation of GRB 210925B
  27. GRB 210926A: AstroSat CZTI detection
  28. GRB 210926A: GECAM detection
  29. IceCube-210922A: JCMT/SCUBA2 observations
  30. GRB 210925A: GECAM detection
  31. IceCube-210922A: No Candidate Counterparts from Swift/XRT follow up observations
  32. IceCube-210922A: No significant detection in HAWC
  33. GRB 210923B: GECAM detection
  34. IceCube-210922A: Upper limits from a search for additional neutrino events in IceCube
  35. IceCube-210922A: No Candidate Counterparts from the Zwicky Transient Facility
  36. GECAM observations of a series of bursts from SGR J1935+2154 (2021-09-15T14 to 2021-09-23T14)
  37. GRB 210919A: DECam Upper Limits
  38. Fermi-LAT Gamma-ray Observations of IceCube-210922A
  39. IceCube Alert 210922.76: Global MASTER-Net observations report
  40. IceCube-210922A - IceCube observation of a high-energy neutrino candidate track-like event
  41. GRB 210912A: LBT optical observations
  42. GRB 210919A: LOAO and LSGT optical upper limits
  43. GRB 210919A: MITSuME Akeno optical upper limits
  44. GRB 210919A: NOT upper limits
  45. GRB 210919A: AbAO optical upper limit
  46. Swift GRB 210919A: Global MASTER-Net observations report
  47. GECAM observations of bursts from SGR J1935+2154 (2021-09-13T01 to 2021-09-15T14)
  48. GECAM observations of bursts from SGR J1935+2154 (2021-09-12T05 to 2021-09-13T01)
  49. AGILE observations of two bright bursts from SGR 1935+2154
  50. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  51. Fermi trigger No 653151835: Global MASTER-Net observations report
  52. Fermi trigger No 653124492: Global MASTER-Net observations report
  53. Fermi trigger No 653122278: Global MASTER-Net observations report
  54. GRB 210912A: Mondy optical afterglow confirmation
  55. Swift GRB 210912A: Global MASTER-Net observations report
  56. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  57. Fermi trigger No 653093506: Global MASTER-Net observations report
  58. Fermi trigger No 653066776: Global MASTER-Net observations report
  59. Fermi trigger No 653084584: Global MASTER-Net observations report
  60. Fermi trigger No 653083551: Global MASTER-Net observations report
  61. Fermi trigger No 653079281: Global MASTER-Net observations report
  62. Fermi trigger No 653066130: Global MASTER-Net observations report
  63. Fermi trigger No 653072474: Global MASTER-Net observations report
  64. Fermi trigger No 653071808: Global MASTER-Net observations report
  65. Fermi trigger No 653054042: Global MASTER-Net observations report
  66. Fermi trigger No 653049776: Global MASTER-Net observations report
  67. Fermi trigger No 653022153: Global MASTER-Net observations report
  68. Fermi trigger No 653031163: Global MASTER-Net observations report
  69. Swift GRB210910.42: Global MASTER-Net observations report
  70. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  71. Fermi trigger No 653010039: Global MASTER-Net observations report
  72. Fermi trigger No 652957973: Global MASTER-Net observations report
  73. Fermi trigger No 652944960: Global MASTER-Net observations report
  74. Fermi trigger No 652981861: Global MASTER-Net observations report
  75. GRB 210909B: GECAM detection
  76. GECAM observations of a series of bursts from SGR J1935+2154
  77. Swift detection of a burst from SGR Swift J1555.2-5402
  78. Fermi trigger No 652934203: Global MASTER-Net observations report
  79. GECAM observation of a burst from SGR J1935+2154
  80. GECAM observation of a burst from SGR J1935+2154
  81. Fermi trigger No 652927551: Global MASTER-Net observations report
  82. Fermi trigger No 652911693: Global MASTER-Net observations report
  83. Fermi trigger No 652906639: Global MASTER-Net observations report
  84. Fermi GRB 210909A: Global MASTER-Net observations report
  85. GECAM observation of a burst from SGR J1555.2-5402
  86. GRB 210905A: AstroSat CZTI detection
  87. GRB 210905A, GROND observations
  88. Fermi GBM Sub-Threshold Detection of GRB 210905A
  89. Fermi trigger No 652585475: Global MASTER-Net observations report
  90. GRB 210905A: DECam Detection
  91. GRB 210905A: LCO Optical Detection
  92. Swift GRB 210905A: Global MASTER-Net observations report
  93. GRB 210905A: Swift detection of a burst
  94. Fermi GRB 210904A: Global MASTER-Net observations report
  95. Swift GRB210903.59: Global MASTER-Net observations report
  96. Swift GRB210903.58: Global MASTER-Net observations report
  97. Swift GRB210903.58: Global MASTER-Net observations report
  98. Fermi GRB 210903A: Global MASTER-Net observations report
  99. Fermi GRB 210903B: Global MASTER-Net observations report
  100. Swift GRB 210901A: Global MASTER-Net observations report

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