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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"

12185 results found.

  1. GRB 210102C: Swift detection of a burst
  2. GRB 210102B: MAXI/GSC detection
  3. Fermi GRB 210101A: Global MASTER-Net observations report
  4. Swift GRB210102.01: Global MASTER-Net observations report
  5. Fermi trigger No 631226368: Global MASTER-Net observations report
  6. Fermi trigger No 631119348: Global MASTER-Net observations report
  7. Fermi trigger No 631113166: Global MASTER-Net observations report
  8. Fermi trigger No 631118376: Global MASTER-Net observations report
  9. Fermi trigger No 631104264: Global MASTER-Net observations report
  10. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  11. Baksan Neutrino Observatory Alert 201230.40: Global MASTER-Net observations report
  12. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  13. GRB 201229A: Swift-XRT refined Analysis
  14. Konus-Wind observation of GRB 201227A
  15. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  16. GRB 201229B: Fermi GBM Final Real-time Localization
  17. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  18. GRB 201020B: Assy, Koshka, Mondy and Maidanak optical observations
  19. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  20. Fermi trigger No 630681391: Global MASTER-Net observations report
  21. GRB 201223A: Swift-XRT refined Analysis
  22. GRB 201223A: iTelescope optical afterglow observations
  23. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  24. IceCube-201221A: Upper limits from a search for additional neutrino events in IceCube
  25. IceCube-201222A: No significant detection in HAWC
  26. IceCube-201221A: No significant detection in HAWC
  27. GRB 201221A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  28. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  29. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  30. Konus-Wind detection of GRB 201221D (short)
  31. IceCube-201222A: IceCube observation of a high-energy neutrino candidate event
  32. GRB 201221A: Swift-XRT refined Analysis
  33. IceCube-201221A: IceCube observation of a high-energy neutrino candidate event
  34. GRB 201221A: FRAM-Auger optical limit
  35. Swift GRB 201221A: Global MASTER-Net observations report
  36. GRB 201221A: Swift detection of a burst
  37. Konus-Wind observation of GRB 201218A
  38. GRB 201214A: Swift-XRT afterglow detection
  39. Fermi GRB 201218A: Global MASTER-Net observations report
  40. Konus-Wind detection of GRB 201216C
  41. IceCube-201209A : MAXI/GSC upper limit
  42. GRB 201216C: Swift-BAT refined analysis
  43. GRB 201216C: Fermi-LAT upper limit
  44. GRB 201216C: AstroSat CZTI detection
  45. GRB 201216C: Swift-XRT observations
  46. GRB 201216C: Swift detection of a burst
  47. Fermi GRB 201216A: Global MASTER-Net observations report
  48. GRB 201216B: AGILE detection of a burst
  49. Chandra observations of GW170817 at ~3.3 years since merger (Full report)
  50. IceCube-201209: No significant detection in HAWC
  51. Potential X-ray KN afterglow from Chandra observations of GW170817 ~3.3 years since merger (3 Epochs of 4)
  52. GRB 201214A: Mates' birthday GRB optical limit from FRAM-ORM
  53. GRB 201214A: A long GRB detected by INTEGRAL
  54. Integral GRB201214.26: Global MASTER-Net observations report
  55. GRB 201015A: optical observations and supernova identification
  56. GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit
  57. Fermi-LAT Gamma-ray Observations of IceCube-201209A
  58. GRB 201209A: Swift-BAT refined analysis
  59. Chandra observations of GW170817 at ~3.3 years since merger (Observation 1 of 4)
  60. GRB 201209A: Swift-XRT refined Analysis
  61. IceCube-201209A: IceCube observation of a high-energy neutrino candidate event
  62. GRB 201209A: AstroSat CZTI detection
  63. GRB 201207A: AGILE detection
  64. GRB 201209A: KAIT Optical Upper Limit
  65. GRB 201209A: FRAM-Auger optical limit
  66. GRB 201209A: Swift detection of a burst
  67. GRB 201208A: Fermi-LAT detection
  68. GRB 201208A: AstroSat CZTI detection
  69. GRB 201203A: Swift-BAT refined analysis
  70. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  71. GRB 201203A: Swift-XRT afterglow detection
  72. GRB 201203A: KAIT Optical Upper Limit
  73. GRB 201203A: FRAM-Auger optical limit
  74. GRB 201203A: Swift detection of a burst
  75. IceCube-201130A: No significant detection in HAWC
  76. IceCube-201130A: Upper limits from a search for additional neutrino events in IceCube
  77. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  78. Swift observations of the Fermi-LAT source 4FGL J0206.4-1151 in the error region of IceCube-201130A
  79. Fermi-LAT Gamma-ray Observations of IceCube-201130A
  80. Fermi GRB 201201A: Global MASTER-Net observations report
  81. Swift-XRT observations of IceCube 201130A
  82. IceCube-201130A: IceCube observation of a high-energy neutrino candidate event
  83. IceCube Alert 201130.85: Global MASTER-Net observations report
  84. GRB 201128A: Swift-XRT refined Analysis
  85. Fermi trigger No 628278856: Global MASTER-Net observations report
  86. GRB 201128A: Swift detection of a burst
  87. IceCube-201114A: Updated photometry for three DECam candidate optical counterparts
  88. IceCube-201120A in the Cygnus region: No enhanced TeV gamma-ray flux detected by HAWC
  89. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  90. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  91. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  92. GRB 201015A radio afterglow with e-MERLIN
  93. Fermi GRB 201120B: Global MASTER-Net observations report
  94. GRB 201120B: Fermi GBM Final Localization
  95. GRB 201120A: Fermi GBM Final Localization
  96. IceCube-201120A: Upper limits from Fermi-GBM Observations
  97. Fermi trigger No 627557935: Global MASTER-Net observations report
  98. Baksan Neutrino Observatory Alert 201120.43: Global MASTER-Net observations report
  99. IceCube Alert 201120.41: Global MASTER-Net observations report
  100. IceCube-201120A: IceCube observation of a high-energy neutrino candidate event

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