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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"

5859 results found.

  1. GRB 200826A: TNG and LBT constraints on a supernova bump
  2. IceCube-201120A: Upper limits from a search for additional neutrino events in IceCube
  3. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  4. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  5. GRB 201120A: Fermi GBM Final Localization
  6. Fermi trigger No 627557935: Global MASTER-Net observations report
  7. IceCube-201120A: IceCube observation of a high-energy neutrino candidate event
  8. GRB 201116A: OSN Afterglow Candidate
  9. Fermi trigger No 627198169: Global MASTER-Net observations report
  10. IceCube Alert 201114.63: Global MASTER-Net observations report
  11. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  12. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy continued optical observations
  13. Swift Trigger 1005428: Detection of SGR 1830-0645
  14. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy, Kitab, TSHAO optical observations
  15. Fermi GRB 201109A: Global MASTER-Net observations report
  16. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201107A
  17. ZTF20acozryr/AT2020yxz (GRB 201103B): Assy optical observations
  18. GRB 201105B: Fermi GBM observation
  19. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  20. GRB 201103A: Fermi GBM Final Real-time Localization
  21. GRB 201031A: Swift detection of a burst
  22. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  23. GRB 201027A: Swift detection of a burst
  24. GRB 201026A: Swift detection of a burst
  25. GRB 201024A: 1.3m DFOT optical observations
  26. Swift GRB201024A: Global MASTER-Net OT detection
  27. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  28. IceCube-201021A: Upper limits from a search for additional neutrino events in IceCube
  29. GRB200826A: GMOS-N detection of a supernova bump
  30. Fermi GRB 201020B: Global MASTER-Net observations report
  31. GRB 201020A: MITSuME Akeno optical observation
  32. GRB 201014A: MMT afterglow detection
  33. GRB 201017A: Fermi GBM detection
  34. GRB 201017A: Swift detection of a burst
  35. GRB 201017A: Fermi GBM Final Real-time Localization
  36. IceCube-201014A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 201013A: Swift detection of a burst
  38. GRB 201006A: Chandra upper limit on the X-ray afterglow
  39. IceCube-201007A: Upper limits from a search for additional neutrino events in IceCube
  40. GRB 201009A: AstroSat CZTI detection
  41. GRB 201009A: AGILE detection of a burst
  42. Fermi trigger No 623873165: Global MASTER-Net observations report
  43. GRB 201006A: GROWTH-India Telescope optical upper limit
  44. GRB 201006A: Enhanced Swift-XRT position
  45. GRB 201006A: Swift detection of a burst
  46. Fermi trigger No 623470566: Global MASTER-Net observations report
  47. IceCube-200926A: No usable INTEGRAL data
  48. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  49. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  50. IceCube-200926A: No candidate counterparts from the Zwicky Transient Facility
  51. IceCube-200926A: JCMT/SCUBA2 observations
  52. IceCube-200929A: No significant detection in HAWC
  53. IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube
  54. GRB 201001A: Fermi GBM observation
  55. GRB 201001A: Swift detection of a burst
  56. GRB 201001A: Fermi GBM Final Real-time Localization
  57. Fermi-LAT Gamma-ray Observations of IceCube-200929A
  58. IceCube-200926B: No significant detection in HAWC
  59. GRB 200928B: Insight-HXMT/HE detection
  60. IceCube-200929A: IceCube observation of a high-energy neutrino candidate event
  61. IceCube Alert 200929.74: Global MASTER-Net observations report
  62. IceCube-200926A: No significant detection in HAWC
  63. Fermi GRB 200929A: Global MASTER-Net observations report
  64. GRB 200928B: AstroSat CZTI detection
  65. IceCube-200926B: Upper limits from a search for additional neutrino events in IceCube
  66. IceCube-200926A: Upper limits from a search for additional neutrino events in IceCube
  67. IceCube-200926A: No Candidate Counterparts from the Zwicky Transient Facility
  68. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  69. IceCube Alert 200926.94: Global MASTER-Net observations report
  70. Swift-XRT observations of IceCube 200926A
  71. Fermi-LAT Gamma-ray Observations of IceCube-200926A
  72. IceCube Alert 200926.33: Global MASTER-Net observations report
  73. IceCube-200926B: IceCube observation of a high-energy neutrino candidate event
  74. GRB 200922A: Chilescope optical observations
  75. IceCube-200926A: IceCube observation of a high-energy neutrino candidate event
  76. Swift GRB 200925B: Global MASTER-Net OT detection
  77. GRB 200925B: OSN Afterglow Candidate Discovery
  78. Swift GRB200925.91: Global MASTER-Net observations report
  79. Fermi GRB 200925A: Global MASTER-Net observations report
  80. Fermi GRB 200924A: Global MASTER-Net observations report
  81. Fermi trigger No 622618714: Global MASTER-Net observations report
  82. GRB 200922A: Insight-HXMT/HE detection
  83. GRB 200924A: Fermi GBM Final Real-time Localization
  84. Fermi GRB 200923A: Global MASTER-Net observations report
  85. IceCube Alert 200921.80: Global MASTER-Net observations report
  86. IceCube-200921A: Upper limits from a search for additional neutrino events in IceCube
  87. Fermi-LAT Gamma-ray Observations of IceCube-200921A and detection of a new gamma-ray source, Fermi J1256.9+2630
  88. IceCube-200921A: no significant detection in HAWC observations
  89. Fermi GRB 200922B: Global MASTER-Net observations report
  90. Swift GRB 200922A: Global MASTER-Net observations report
  91. GRB 200919C: Insight-HXMT/HE detection
  92. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  93. IceCube-200921A: IceCube observation of a high-energy neutrino candidate event
  94. GRB 200920B: AGILE/MCAL detection of a burst
  95. Fermi GRB 200919C: Global MASTER-Net observations report
  96. GRB 200919A: CrAO/ZTSh early optical upper limit
  97. Fermi GRB 200919B: Global MASTER-Net observations report
  98. GRB 200916B: MASTER optical observation
  99. Swift GRB200919.08: Global MASTER-Net observations report
  100. IceCube-200916A: AbAO observations of optical candidates ZTF20acaapwk/AT2020tno, ZTF20acaapwo/AT2020tnp

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