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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. Fermi trigger No 631104264: Global MASTER-Net observations report
  2. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  3. Baksan Neutrino Observatory Alert 201230.40: Global MASTER-Net observations report
  4. GRB 201227A: Chilescope optical observations, possible optical counterpart
  5. GRB 201227A: GRAWITA VST-ESO PARANAL observations
  6. GRB 201227A: Fermi GBM observation
  7. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  8. GRB 201229A: SAO RAS optical observations
  9. GRB 201229A: Nanshan/NEXT optical upper limit
  10. GRB 201227A: Swift-XRT observations
  11. GRB 201223A: SVOM-GWAC detected the optical counterpart during prompt emission phase
  12. GRB 201229A: Swift-XRT refined Analysis
  13. GRB 201229A: Swift-BAT refined analysis
  14. GRB 201104B: Maidanak and CrAO optical observations
  15. Fermi GRB 201229B: Global MASTER-Net observations report
  16. Konus-Wind observation of GRB 201227A
  17. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  18. GRB 201229B: Fermi GBM Final Real-time Localization
  19. GRB 201229A: Enhanced Swift-XRT position
  20. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  21. GRB 201020B: Assy, Koshka, Mondy and Maidanak optical observations
  22. Baksan Neutrino Observatory Alert 201228.36: Global MASTER-Net observations report
  23. Fermi GRB 201228B: Global MASTER-Net observations report
  24. GRB 201228B: Fermi GBM Final Real-time Localization
  25. GRB 201227A: Insight-HXMT/HE detection
  26. GRB 201226A: Insight-HXMT/HE detection
  27. GRB 201227A: Tiled Swift observations
  28. GRB 201227A: Swift ToO observations
  29. GRB 201228A: Fermi GBM Final Real-time Localization
  30. IPN triangulation of GRB 201227A (short)
  31. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  32. GRB 201223A: AROMA-N Optical Observation
  33. GRB 201227A: AGILE detection of a burst
  34. Fermi trigger No 630681391: Global MASTER-Net observations report
  35. GRB 201223A: Swift/UVOT Detection
  36. GRB 201223A: HCT optical upper limit
  37. Baksan Neutrino Observatory Alert 201225.54: Global MASTER-Net observations report
  38. GRB 201223A: AbAO optical observations
  39. GRB 201223A: 1.3m DFOT and 1.04m ST optical observations
  40. IceCube-201222A: No Candidate Counterparts from the Zwicky Transient Facility
  41. GRB 201223A: Swift-XRT refined Analysis
  42. GRB 201223A: Enhanced Swift-XRT position
  43. GRB 201223A: NOT optical upper limit and NEXT powerlaw decay
  44. GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up.
  45. GRB 201223A: Mondy and Kitab optical observations
  46. GRB 201223A: GWAC-F60A optical afterglow observations
  47. GRB 201223A: iTelescope optical afterglow observations
  48. GRB 201223A: MITSuME Akeno optical observation
  49. GRB 201223A: Swift-BAT refined analysis
  50. Baksan Neutrino Observatory Alert 201223.60: Global MASTER-Net observations report
  51. GRB 201223A: Fermi GBM Detection
  52. GRB 201223A: BOOTES-4/MET early optical observation
  53. GRB 201223A: Nanshan/NEXT early optical afterglow detection
  54. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  55. Swift GRB201223.75: Global MASTER-Net OT detection
  56. Swift GRB201223.75: Global MASTER-Net observations report
  57. Swift-XRT observations of Icecube 201222A
  58. IceCube-201222A: Upper limits from a search for additional neutrino events in IceCube
  59. IceCube-201221A: Upper limits from a search for additional neutrino events in IceCube
  60. IceCube-201222A: No significant detection in HAWC
  61. IceCube-201221A: No significant detection in HAWC
  62. GRB 201221A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  63. GRB 201221A: REM early-time afterglow detection
  64. GRB 201221D: 3.6m DOT optical observations
  65. GRB 201221B: Insight-HXMT/HE detection
  66. IceCube-201221A: Upper limits from Insight-HXMT/HE observations
  67. Fermi trigger No 630389391: Global MASTER-Net observations report
  68. GRB 201221D: SMA submm observation
  69. Fermi GRB 201222B: Global MASTER-Net observations report
  70. GRB 201221D: MMT MMIRS detection of marginally extended source
  71. GRB 201221D: LCOGT upper limits
  72. GRB 201221D: Fermi GBM detection
  73. GRB 201221D: Swift-BAT refined analysis
  74. Swift Trigger 1014012 (possible GRB 201221C) is likely not an astrophysical event
  75. GRB 201216A - further Swift-XRT observations
  76. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  77. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  78. IceCube-201222A: not observable by Fermi-GBM
  79. GRB 201221D: Archival PS1 Imaging of the Putative Host Galaxy
  80. Short GRB201221D: High Redshift from OSIRIS/GTC
  81. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. Konus-Wind detection of GRB 201221D (short)
  83. GRB 201221D: Swift/UVOT Upper Limits
  84. GRB 201221D: Lowell Discovery Telescope afterglow observations
  85. GRB 201222B: BALROG localization (Fermi Trigger / GRB 201222461)
  86. GRB 201222B: Fermi GBM Final Real-time Localization
  87. GRB 201221D: FRAM-ORM optical limit
  88. GRB 201221D: Swift-XRT refined Analysis
  89. IceCube Alert 201222.04: Global MASTER-Net observations report
  90. Swift GRB 201221D: Global MASTER-Net observations report
  91. Fermi GRB 201221E: Global MASTER-Net observations report
  92. IceCube-201222A: IceCube observation of a high-energy neutrino candidate event
  93. GRB 201221D: Enhanced Swift-XRT position
  94. GRB 201221D: Nanshan/NEXT early optical upper limit
  95. GRB 201221D: candidate optical counterpart from the NOT
  96. GRB 201221A: Swift-BAT refined analysis
  97. GRB 201222A: Fermi GBM Final Real-time Localization
  98. GRB 201221E: Fermi GBM Final Real-time Localization
  99. GRB 201221D: Prompt enhanced Swift-XRT position
  100. GRB 201221D: Swift detection of a bright short burst

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