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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"

5848 results found.

  1. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy continued optical observations
  2. Swift Trigger 1005428: Detection of SGR 1830-0645
  3. ZTF20acozryr/AT2020yxz (GRB 201103B): Mondy, Kitab, TSHAO optical observations
  4. Fermi GRB 201109A: Global MASTER-Net observations report
  5. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-201107A
  6. ZTF20acozryr/AT2020yxz (GRB 201103B): Assy optical observations
  7. GRB 201105B: Fermi GBM observation
  8. ZTF20acozryr/AT2020yxz: Zwicky Transient Facility discovery of a fast optical transient with no associated GRB
  9. GRB 201103A: Fermi GBM Final Real-time Localization
  10. GRB 201031A: Swift detection of a burst
  11. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  12. GRB 201027A: Swift detection of a burst
  13. GRB 201026A: Swift detection of a burst
  14. GRB 201024A: 1.3m DFOT optical observations
  15. Swift GRB201024A: Global MASTER-Net OT detection
  16. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  17. IceCube-201021A: Upper limits from a search for additional neutrino events in IceCube
  18. GRB200826A: GMOS-N detection of a supernova bump
  19. Fermi GRB 201020B: Global MASTER-Net observations report
  20. GRB 201020A: MITSuME Akeno optical observation
  21. GRB 201014A: MMT afterglow detection
  22. GRB 201017A: Fermi GBM detection
  23. GRB 201017A: Swift detection of a burst
  24. GRB 201017A: Fermi GBM Final Real-time Localization
  25. IceCube-201014A: Upper limits from a search for additional neutrino events in IceCube
  26. GRB 201013A: Swift detection of a burst
  27. GRB 201006A: Chandra upper limit on the X-ray afterglow
  28. IceCube-201007A: Upper limits from a search for additional neutrino events in IceCube
  29. GRB 201009A: AstroSat CZTI detection
  30. GRB 201009A: AGILE detection of a burst
  31. Fermi trigger No 623873165: Global MASTER-Net observations report
  32. GRB 201006A: GROWTH-India Telescope optical upper limit
  33. GRB 201006A: Enhanced Swift-XRT position
  34. GRB 201006A: Swift detection of a burst
  35. Fermi trigger No 623470566: Global MASTER-Net observations report
  36. IceCube-200926A: No usable INTEGRAL data
  37. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  38. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  39. IceCube-200926A: No candidate counterparts from the Zwicky Transient Facility
  40. IceCube-200926A: JCMT/SCUBA2 observations
  41. IceCube-200929A: No significant detection in HAWC
  42. IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube
  43. GRB 201001A: Fermi GBM observation
  44. GRB 201001A: Swift detection of a burst
  45. GRB 201001A: Fermi GBM Final Real-time Localization
  46. Fermi-LAT Gamma-ray Observations of IceCube-200929A
  47. IceCube-200926B: No significant detection in HAWC
  48. GRB 200928B: Insight-HXMT/HE detection
  49. IceCube-200929A: IceCube observation of a high-energy neutrino candidate event
  50. IceCube Alert 200929.74: Global MASTER-Net observations report
  51. IceCube-200926A: No significant detection in HAWC
  52. Fermi GRB 200929A: Global MASTER-Net observations report
  53. GRB 200928B: AstroSat CZTI detection
  54. IceCube-200926B: Upper limits from a search for additional neutrino events in IceCube
  55. IceCube-200926A: Upper limits from a search for additional neutrino events in IceCube
  56. IceCube-200926A: No Candidate Counterparts from the Zwicky Transient Facility
  57. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  58. IceCube Alert 200926.94: Global MASTER-Net observations report
  59. Swift-XRT observations of IceCube 200926A
  60. Fermi-LAT Gamma-ray Observations of IceCube-200926A
  61. IceCube Alert 200926.33: Global MASTER-Net observations report
  62. IceCube-200926B: IceCube observation of a high-energy neutrino candidate event
  63. GRB 200922A: Chilescope optical observations
  64. IceCube-200926A: IceCube observation of a high-energy neutrino candidate event
  65. Swift GRB 200925B: Global MASTER-Net OT detection
  66. GRB 200925B: OSN Afterglow Candidate Discovery
  67. Swift GRB200925.91: Global MASTER-Net observations report
  68. Fermi GRB 200925A: Global MASTER-Net observations report
  69. Fermi GRB 200924A: Global MASTER-Net observations report
  70. Fermi trigger No 622618714: Global MASTER-Net observations report
  71. GRB 200922A: Insight-HXMT/HE detection
  72. GRB 200924A: Fermi GBM Final Real-time Localization
  73. Fermi GRB 200923A: Global MASTER-Net observations report
  74. IceCube Alert 200921.80: Global MASTER-Net observations report
  75. IceCube-200921A: Upper limits from a search for additional neutrino events in IceCube
  76. Fermi-LAT Gamma-ray Observations of IceCube-200921A and detection of a new gamma-ray source, Fermi J1256.9+2630
  77. IceCube-200921A: no significant detection in HAWC observations
  78. Fermi GRB 200922B: Global MASTER-Net observations report
  79. Swift GRB 200922A: Global MASTER-Net observations report
  80. GRB 200919C: Insight-HXMT/HE detection
  81. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. IceCube-200921A: IceCube observation of a high-energy neutrino candidate event
  83. GRB 200920B: AGILE/MCAL detection of a burst
  84. Fermi GRB 200919C: Global MASTER-Net observations report
  85. GRB 200919A: CrAO/ZTSh early optical upper limit
  86. Fermi GRB 200919B: Global MASTER-Net observations report
  87. GRB 200916B: MASTER optical observation
  88. Swift GRB200919.08: Global MASTER-Net observations report
  89. IceCube-200916A: AbAO observations of optical candidates ZTF20acaapwk/AT2020tno, ZTF20acaapwo/AT2020tnp
  90. IceCube-200916A: Upper limits from a search for additional neutrino events in IceCube
  91. GRB 200916B: AstroSat CZTI detection
  92. GRB 200917A: GROWTH-India Telescope optical upper limit.
  93. IceCube-200916A: No significant detection in HAWC
  94. IceCube-200916A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  95. Swift GRB 200917A: Global MASTER-Net observations report
  96. IceCube-200916A: Two Candidate Counterparts from the Zwicky Transient Facility
  97. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  98. IceCube Alert 200916.86: Global MASTER-Net observations report
  99. IceCube-200916A - IceCube observation of a high-energy neutrino candidate track-like event
  100. Fermi GRB 200916A: Global MASTER-Net observations report

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