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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"

12180 results found.

  1. Fermi trigger No 631119348: Global MASTER-Net observations report
  2. Fermi trigger No 631113166: Global MASTER-Net observations report
  3. Fermi trigger No 631118376: Global MASTER-Net observations report
  4. Fermi trigger No 631104264: Global MASTER-Net observations report
  5. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  6. Baksan Neutrino Observatory Alert 201230.40: Global MASTER-Net observations report
  7. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  8. GRB 201229A: Swift-XRT refined Analysis
  9. Konus-Wind observation of GRB 201227A
  10. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  11. GRB 201229B: Fermi GBM Final Real-time Localization
  12. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  13. GRB 201020B: Assy, Koshka, Mondy and Maidanak optical observations
  14. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  15. Fermi trigger No 630681391: Global MASTER-Net observations report
  16. GRB 201223A: Swift-XRT refined Analysis
  17. GRB 201223A: iTelescope optical afterglow observations
  18. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  19. IceCube-201221A: Upper limits from a search for additional neutrino events in IceCube
  20. IceCube-201222A: No significant detection in HAWC
  21. IceCube-201221A: No significant detection in HAWC
  22. GRB 201221A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  23. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  24. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  25. Konus-Wind detection of GRB 201221D (short)
  26. IceCube-201222A: IceCube observation of a high-energy neutrino candidate event
  27. GRB 201221A: Swift-XRT refined Analysis
  28. IceCube-201221A: IceCube observation of a high-energy neutrino candidate event
  29. GRB 201221A: FRAM-Auger optical limit
  30. Swift GRB 201221A: Global MASTER-Net observations report
  31. GRB 201221A: Swift detection of a burst
  32. Konus-Wind observation of GRB 201218A
  33. GRB 201214A: Swift-XRT afterglow detection
  34. Fermi GRB 201218A: Global MASTER-Net observations report
  35. Konus-Wind detection of GRB 201216C
  36. IceCube-201209A : MAXI/GSC upper limit
  37. GRB 201216C: Swift-BAT refined analysis
  38. GRB 201216C: Fermi-LAT upper limit
  39. GRB 201216C: AstroSat CZTI detection
  40. GRB 201216C: Swift-XRT observations
  41. GRB 201216C: Swift detection of a burst
  42. Fermi GRB 201216A: Global MASTER-Net observations report
  43. GRB 201216B: AGILE detection of a burst
  44. Chandra observations of GW170817 at ~3.3 years since merger (Full report)
  45. IceCube-201209: No significant detection in HAWC
  46. Potential X-ray KN afterglow from Chandra observations of GW170817 ~3.3 years since merger (3 Epochs of 4)
  47. GRB 201214A: Mates' birthday GRB optical limit from FRAM-ORM
  48. GRB 201214A: A long GRB detected by INTEGRAL
  49. Integral GRB201214.26: Global MASTER-Net observations report
  50. GRB 201015A: optical observations and supernova identification
  51. GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit
  52. Fermi-LAT Gamma-ray Observations of IceCube-201209A
  53. GRB 201209A: Swift-BAT refined analysis
  54. Chandra observations of GW170817 at ~3.3 years since merger (Observation 1 of 4)
  55. GRB 201209A: Swift-XRT refined Analysis
  56. IceCube-201209A: IceCube observation of a high-energy neutrino candidate event
  57. GRB 201209A: AstroSat CZTI detection
  58. GRB 201207A: AGILE detection
  59. GRB 201209A: KAIT Optical Upper Limit
  60. GRB 201209A: FRAM-Auger optical limit
  61. GRB 201209A: Swift detection of a burst
  62. GRB 201208A: Fermi-LAT detection
  63. GRB 201208A: AstroSat CZTI detection
  64. GRB 201203A: Swift-BAT refined analysis
  65. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  66. GRB 201203A: Swift-XRT afterglow detection
  67. GRB 201203A: KAIT Optical Upper Limit
  68. GRB 201203A: FRAM-Auger optical limit
  69. GRB 201203A: Swift detection of a burst
  70. IceCube-201130A: No significant detection in HAWC
  71. IceCube-201130A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  73. Swift observations of the Fermi-LAT source 4FGL J0206.4-1151 in the error region of IceCube-201130A
  74. Fermi-LAT Gamma-ray Observations of IceCube-201130A
  75. Fermi GRB 201201A: Global MASTER-Net observations report
  76. Swift-XRT observations of IceCube 201130A
  77. IceCube-201130A: IceCube observation of a high-energy neutrino candidate event
  78. IceCube Alert 201130.85: Global MASTER-Net observations report
  79. GRB 201128A: Swift-XRT refined Analysis
  80. Fermi trigger No 628278856: Global MASTER-Net observations report
  81. GRB 201128A: Swift detection of a burst
  82. IceCube-201114A: Updated photometry for three DECam candidate optical counterparts
  83. IceCube-201120A in the Cygnus region: No enhanced TeV gamma-ray flux detected by HAWC
  84. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  85. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  86. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  87. GRB 201015A radio afterglow with e-MERLIN
  88. Fermi GRB 201120B: Global MASTER-Net observations report
  89. GRB 201120B: Fermi GBM Final Localization
  90. GRB 201120A: Fermi GBM Final Localization
  91. IceCube-201120A: Upper limits from Fermi-GBM Observations
  92. Fermi trigger No 627557935: Global MASTER-Net observations report
  93. Baksan Neutrino Observatory Alert 201120.43: Global MASTER-Net observations report
  94. IceCube Alert 201120.41: Global MASTER-Net observations report
  95. IceCube-201120A: IceCube observation of a high-energy neutrino candidate event
  96. ZTF20acozryr/AT2020yxz (GRB 201103B): SAO RAS optical observations
  97. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  98. Konus-Wind detection of GRB 201116A
  99. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  100. GRB 201116A: Swift-XRT afterglow detection

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