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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"
  1. GRB 201016A: Fermi GBM Final Real-time Localization
  2. GRB 201015A: Swift-XRT observations
  3. Swift GRB 201015A: Global MASTER-Net observations report
  4. Swift GRB201015.95: Global MASTER-Net OT detection
  5. GRB 201015A: Swift detection of a burst
  6. IceCube-201014A: Upper limits from a search for additional neutrino events in IceCube
  7. GRB 201014A: BOOTES-1 and -2 early optical upper limits
  8. GRB 201014A: Swift-BAT refined analysis
  9. GRB 201014A (Swift trigger =1000255): CrAO/ZTSH optical afterglow discovery
  10. IceCube Alert 201014.09: Global MASTER-Net observations report
  11. Swift-BAT trigger 1000255: XRT afterglow detection of GRB 201014A
  12. GRB 201013A: Insight-HXMT/HE detection
  13. IceCube-201014A: No neutrino counterpart candidates in ANTARES search
  14. Swift Trigger 1000255 is probably not a GRB
  15. Fermi-LAT Gamma-ray Observations of IceCube-201014A
  16. GRB 201013A: TSHAO and AbAO optical observations, afterglow confirmation
  17. GRB 201013A: AstroSat CZTI detection
  18. IceCube-201014A: Not observable by GBM
  19. GRB 201013A: CALET Gamma-Ray Burst Monitor detection
  20. IceCube-201014A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. IceCube-201014A - IceCube observation of a high-energy neutrino candidate track-like event
  22. GRB 201013A: FRAM-ORM possible afterglow candidate
  23. GRB 201013A: Swift-BAT refined analysis
  24. GRB 201013A: Swift/UVOT Upper Limits
  25. Swift GRB 201013A: Global MASTER-Net observations report
  26. GRB 201013A: Swift-XRT refined Analysis
  27. SGR 1830-0645: Swift/UVOT Upper Limits
  28. IceCube-201007A: No candidate counterparts from the Zwicky Transient Facility
  29. GRB 201013A: Enhanced Swift-XRT position
  30. GRB 201013A: Swift detection of a burst
  31. GRB 201011A: Fermi GBM detection of a likely Long GRB in the direction of SGR 1830-0645
  32. Fermi trigger No 624139481: AGILE detection
  33. GRB 201012A: Fermi GBM Final Real-time Localization
  34. SGR 1830-0645: pre-discovery detection in Swift/BAT
  35. Fermi trigger No 624139481: Global MASTER-Net observations report
  36. SGR 1830-0645 / GRB 201010A: 1.5m OSN optical upper limit
  37. Fermi trigger No 624121589: Global MASTER-Net observations report
  38. SGR 1830-0645: Swift-BAT refined analysis
  39. GRB 201006A: Chandra upper limit on the X-ray afterglow
  40. SGR 1830-0645 / GRB 201010A: Kitab optical non-detection
  41. GRB 201010A: Enhanced Swift-XRT position
  42. Swift GRB201010.62: Global MASTER-Net observations report
  43. Swift detection of a new SGR 1830-0645 or a short GRB 201010A
  44. IceCube-200929A: JCMT/SCUBA2 observations
  45. IceCube-201007A: No significant detection in HAWC
  46. GRB 201008B: Fermi GBM Final Localization
  47. IceCube-201007A: Upper limits from a search for additional neutrino events in IceCube
  48. GRB 201009A: AstroSat CZTI detection
  49. GRB 201009A: AGILE detection of a burst
  50. GRB 201008A: Swift-XRT observations
  51. IceCube-200926A: Upper limits from Insight-HXMT Observations
  52. GRB 201008A: Swift ToO observations
  53. IceCube-201007A: Upper limits from Fermi-GBM Observations
  54. GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
  55. Fermi-LAT Gamma-ray Observations of IceCube-201007A
  56. Fermi trigger No 623846261: Global MASTER-Net observations report
  57. Fermi trigger No 623873165: Global MASTER-Net observations report
  58. Swift-XRT observations of IceCube 201007A
  59. Baksan Neutrino Observatory Alert 201008.47: Global MASTER-Net observations report
  60. GRB 201008A: BALROG localization (Fermi Trigger 623846261 / GRB 201008443)
  61. IceCube-201007A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  62. IceCube-201007A - IceCube observation of a high-energy neutrino candidate track-like event
  63. IceCube Alert 201007.92: Global MASTER-Net observations report
  64. GRB 201006A: GROWTH-India Telescope optical upper limit
  65. GRB 201006A: Lowell Discovery Telescope upper limits
  66. GRB 201006A: MITSuME Akeno optical upper limits
  67. Fermi GRB 201007A: Global MASTER-Net observations report
  68. GRB 201007A: Fermi GBM Final Real-time Localization
  69. GRB 201006A: Swift-XRT refined Analysis
  70. GRB 201006A: Swift-BAT refined analysis
  71. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  72. GRB 201006A: Swift/UVOT Upper Limits
  73. GRB 201006A: Fermi GBM detection
  74. GRB 201006A is likely a short burst
  75. GRB 201006A: Enhanced Swift-XRT position
  76. INTEGRAL sub-threshold detection of GRB 201006A
  77. GRB 201006A: Swift detection of a burst
  78. Swift GRB201006.05: Global MASTER-Net observations report
  79. Fermi trigger No 623470566: Global MASTER-Net observations report
  80. GRB 201004A: Fermi GBM Final Localization
  81. Fermi trigger No 623493962: Global MASTER-Net observations report
  82. GRB 201001A: Swift/UVOT Upper Limits
  83. IceCube-200926A: No usable INTEGRAL data
  84. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  85. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  86. IceCube-200926A: No candidate counterparts from the Zwicky Transient Facility
  87. GRB 201001A: TSHAO optical upper limit
  88. GRB 201001A: Xinglong-2.16m optical upper limit
  89. GRB 201001A: MITSuME Akeno optical upper limits
  90. IceCube-200926A: JCMT/SCUBA2 observations
  91. IceCube-200929A: No significant detection in HAWC
  92. GRB 201001A: Swift-BAT refined analysis
  93. GRB 201001A: Swift-XRT refined Analysis
  94. IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube
  95. GRB 201001A: Fermi GBM observation
  96. Swift-XRT observations of IceCube 200929A
  97. GRB 201001A: Enhanced Swift-XRT position
  98. GRB 201001A: Swift detection of a burst
  99. GRB 201001A: Fermi GBM Final Real-time Localization
  100. Fermi-LAT Gamma-ray Observations of IceCube-200929A

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