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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

4738 results found.

  1. GRB 200901A: Fermi GBM observation
  2. GRB 200901A: Swift detection of a burst
  3. Swift GRB200901.16: Global MASTER-Net observations report
  4. Fermi trigger No 620402299: Global MASTER-Net observations report
  5. IPN triangulation of GRB 200826B
  6. Fermi GRB 200824A: Global MASTER-Net observations report
  7. Fermi GRB 200826A: Global MASTER-Net observations report
  8. GRB 200819A: Swift-BAT refined analysis
  9. IPN triangulation of GRB 200815A (short)
  10. GRB 200729A: Lowell Discovery Telescope observations
  11. GRB 200819A: Kitab, TSHAO optical upper limit
  12. GRB 200819A: Enhanced Swift-XRT position
  13. GRB 200819A: Swift detection of a burst
  14. Baksan Neutrino Observatory Alert 200819.09: Global MASTER-Net observations report
  15. Fermi trigger No 619270776: Global MASTER-Net observations report
  16. GRB 200806A: CAHA optical afterglow confirmation
  17. GRB 200803A: Chilescope optical upper limit
  18. GRB 200803B: MASTER possibly OT discovery
  19. GRB 200803A: AstroSat CZTI detection
  20. GRB 200803A: Fermi GBM detection
  21. Fermi GRB 200803B: Global MASTER-Net observations report
  22. GRB 200803A: Fermi-LAT detection
  23. LAT GRB200803.15: Global MASTER-Net observations report
  24. Fermi GRB 200803A: Global MASTER-Net observations report
  25. GRB 200803A: Fermi GBM Final Real-time Localization
  26. Fermi GRB 200801B: Global MASTER-Net observations report
  27. Fermi GRB 200802A: Global MASTER-Net observations report
  28. Fermi GRB 200801A: Global MASTER-Net observations report
  29. IceCube Alert 200728.35: Global MASTER-Net observations report
  30. Baksan Neutrino Observatory Alert 200726.66: Global MASTER-Net observations report
  31. Fermi GRB 200723A: Global MASTER-Net observations report
  32. Fermi GRB 200716B: Global MASTER-Net observations report
  33. Fermi GRB 200714D: Global MASTER-Net observations report
  34. Fermi GRB 200714A: Global MASTER-Net observations report
  35. GRB 200709A: Fermi GBM Final Real-time Localization
  36. GRB 200703B: AstroSat CZTI detection
  37. Fermi GRB 200702A: Global MASTER-Net observations report
  38. Trigger 980513: Swift detection of SGR Swift J1818.0-1607
  39. Fermi GRB 200626A: Global MASTER-Net observations report
  40. GRB 200623A: Fermi GBM observation
  41. IceCube-200620A: No significant detection in HAWC
  42. GRB 200623A: Swift/BAT-GUANO detection and arcminute localization of a short GRB
  43. Fermi GRB 200623A: Global MASTER-Net observations report
  44. GRB 200623A: Fermi GBM Final Real-time Localization
  45. IceCube-200620A: Upper limits from a search for additional neutrino events in IceCube
  46. IceCube-200620A: INTEGRAL was inactive at the time of the event
  47. Fermi-LAT Gamma-ray Observations of IceCube-200620A
  48. IceCube-200620A - IceCube observation of a high-energy neutrino candidate track-like event
  49. GRB 200619C: Fermi GBM Final Real-time Localization
  50. Fermi trigger No 614239407: Global MASTER-Net observations report
  51. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  52. Fermi GRB 200616A: Global MASTER-Net observations report
  53. GRB 200615B: MAXI/GSC detection
  54. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  55. Fermi GRB 200613A: Global MASTER-Net observations report
  56. Fermi GRB 200607B: Global MASTER-Net observations report
  57. Fermi GRB 200607A: Global MASTER-Net observations report
  58. Fermi trigger No 612988790: Global MASTER-Net observations report
  59. Baksan Neutrino Observatory Alert 200603.12: Global MASTER-Net observations report
  60. Fermi GRB 200601A: Global MASTER-Net observations report
  61. IceCube-200530A: No significant detection in HAWC
  62. IceCube Alert 200530.33: Global MASTER-Net observations report
  63. GRB 200529A: Swift detection of a burst
  64. GRB 200524A: CrAO optical observations
  65. Fermi GRB 200524A: Global MASTER-Net observations report
  66. ZTF Discovery of ZTF20abbiixp: The Likely Optical Afterglow to GRB 200524A
  67. GRB 200522A: LCO Optical Afterglow Detection
  68. IceCube Alert 200523.10: Global MASTER-Net observations report
  69. Fermi trigger No 611676654: Global MASTER-Net observations report
  70. Fermi trigger No 611605955: Global MASTER-Net observations report
  71. Fermi trigger No 611434353: Global MASTER-Net observations report
  72. GRB 200517A: MAXI/GSC detection
  73. Swift J1818.0-1607: BOOTES-3/YA optical upper limit
  74. Swift Detection of a burst from SGR Swift J1818.0-1607
  75. GRB 200514A: MITSuME Akeno optical upper limits
  76. GRB 200514A: MAXI/GSC detection
  77. GRB 200512A: LCO Optical Upper Limits
  78. IPN triangulation of a bright burst from SGR 1935+2154 on 2020-05-10 at 06:12 UT
  79. Insight-HXMT detection of a short bright burst from SGR 1935+2154
  80. AGILE detection of a short and hard X-ray burst possibly related to SGR 1935+2154
  81. GRB 200503A: AGILE observations
  82. GRB 200503B: BALROG localization (Fermi Trigger 610219118 / GRB 200503721)
  83. AstroSat CZTI detection : GRB200503A
  84. SGR 1935+2154: MASTER optical observations
  85. A Forest of Bursts from SGR 1935+2154
  86. SGR 1935+2154 the Insight-HXMT observation plan
  87. IceCube-200425A: Upper limits from a search for additional neutrino events in IceCube
  88. IceCube-200421A: Upper limits from a search for additional neutrino events in IceCube
  89. Fermi trigger No 608935505: Global MASTER-Net observations report
  90. GRB 200412B: Optical afterglow detection with 1.3m DFOT
  91. Fermi GRB 200412A: Global MASTER-Net observations report
  92. IceCube-200410A: Upper limits from a search for additional neutrino events in IceCube
  93. Baksan Neutrino Observatory Alert 200409.81: Global MASTER-Net observations report
  94. Fermi GBM Sub-Threshold Detection of GRB 200409A
  95. Baksan Neutrino Observatory Alert 200409.23: Global MASTER-Net observations report
  96. GRB 200409A: Swift detection of a burst with an optical counterpart
  97. Fermi GRB 200407A: Global MASTER-Net observations report
  98. Fermi GRB 200407B: Global MASTER-Net observations report
  99. IPN triangulation of GRB 200405B (short)
  100. Baksan Neutrino Observatory Alert 200406.3: Global MASTER-Net observations report

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