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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"

11051 results found.

  1. Fermi GRB 200803B: Global MASTER-Net observations report
  2. GRB 200803A: Fermi-LAT detection
  3. GRB 200803A: MASTER optical counterpart discovery
  4. GRB 200803B: Fermi GBM Final Real-time Localization
  5. GRB 200803A: Tiled Swift observations
  6. Fermi GRB 200803A: Global MASTER-Net observations report
  7. GRB 200801B: AstroSat CZTI detection
  8. GRB 200803A: Fermi GBM Final Real-time Localization
  9. Fermi GRB 200801B: Global MASTER-Net observations report
  10. Fermi GRB 200802A: Global MASTER-Net observations report
  11. Konus-Wind detection of GRB 200729A
  12. GRB 200802A: BALROG localization (Fermi Trigger 618061611 / GRB 200802491)
  13. GRB 200802A: Fermi GBM Final Real-time Localization
  14. Fermi GRB 200801A: Global MASTER-Net observations report
  15. Swift Detection of an SGR-like flare from AX J1846.4-0258
  16. GRB 200801B: BALROG localization (Fermi Trigger 617988951 / GRB 200801650)
  17. GRB 200801B: Fermi GBM Final Real-time Localization
  18. GRB 200801A: Fermi GBM Final Real-time Localization
  19. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  20. GRB 200723A: ATLAS observations of GOTO candidate AT2020qer
  21. GRB 200723A: Swift ToO observations
  22. GRB 200723A: GOTO candidate afterglow and host galaxy
  23. GRB 200724A: Fermi GBM Final Real-time Localization
  24. Fermi GRB 200723A: Global MASTER-Net observations report
  25. GRB 200723A: BALROG localization (Fermi Trigger 617214929 / GRB 200723691)
  26. GRB 200723A: Fermi GBM Final Real-time Localization
  27. GRB 200716C: Kitab optical observations
  28. GRB 200722A: BALROG localization (Fermi Trigger 617076900 / GRB 200722094)
  29. GRB 200716C: CAHA optical observation // Anomalous light curve behavior?
  30. GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations
  31. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  32. Konus-Wind observation of GRB 200716C
  33. GRB 200716C: Insight-HXMT/HE detection
  34. Fermi GRB 200718A: Global MASTER-Net observations report
  35. Fermi GBM trigger 616776657/200718619 is not a GRB
  36. GRB 200718A: Fermi GBM Final Real-time Localization
  37. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  38. GRB 200716C: Optical observations from HCT
  39. GRB 200716B: Insight-HXMT/HE detection
  40. GRB 200716C: Fermi GBM detection
  41. Fermi GRB 200716A: Global MASTER-Net observations report
  42. GRB 200716C: AGILE/MCAL detection
  43. GRB 200716C: Fermi-LAT detection
  44. GRB 200716C: Fermi GBM Final Real-time Localization
  45. IPN triangulation of GRB 200716A
  46. GRB 200716A: Fermi GBM detection
  47. Fermi GRB 200716B: Global MASTER-Net observations report
  48. GRB 200716B: AstroSat CZTI detection
  49. GRB 200716A: AstroSat CZTI detection
  50. GRB 200716A: AGILE detection
  51. GRB 200716B: BALROG localization (Fermi Trigger 616577673 / GRB 200716316)
  52. GRB 200716B: Fermi GBM Final Real-time Localization
  53. GRB 200716A: BALROG localization (Fermi Trigger 616555602 / GRB 200716060)
  54. GRB 200716A: Fermi GBM Final Real-time Localization
  55. GRB 200714E: Fermi GBM observation
  56. GRB 200714E: Swift-XRT observations
  57. Fermi GRB 200714E: Global MASTER-Net observations report
  58. GRB 200714E: AGILE detection
  59. GRB 200714E: Swift/BAT-GUANO detection and arcminute localization
  60. Fermi GRB 200714D: Global MASTER-Net observations report
  61. Fermi GRB 200714A: Global MASTER-Net observations report
  62. GRB 200714E: BALROG localization (Fermi Trigger 616444510 / GRB 200714774)
  63. GRB 200714E: Fermi GBM Final Real-time Localization
  64. GRB 200714D: Fermi GBM Final Real-time Localization
  65. GRB 200714C: Fermi GBM Final Real-time Localization
  66. GRB 200711A: Insight-HXMT/HE detection
  67. GRB 200714B: Fermi GBM Final Real-time Localization
  68. GRB 200714A: Fermi GBM Final Real-time Localization
  69. Fermi trigger No 616370565: Global MASTER-Net observations report
  70. GRB 200711A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 200711A: AbAO optical upper limit
  72. GRB 200711A: Fermi-LAT marginal detection
  73. GRB 200711A: KAIT Optical Upper Limit
  74. GRB 200711A: Fermi GBM detection
  75. GRB 200711A: Fermi GBM Final Real-time Localization
  76. GRB 200710A: Fermi GBM Final Real-time Localization
  77. GRB 200709A: Fermi GBM Final Real-time Localization
  78. GRB 200707A: Insight-HXMT/HE detection
  79. GRB 200707A: Fermi GBM Final Localization
  80. Fermi trigger No 615741133: Global MASTER-Net observations report
  81. GRB 200706A: Fermi GBM Final Real-time Localization
  82. Fermi GRB 200705A: Global MASTER-Net observations report
  83. Fermi-LAT-ANTARES 200407a Coincidence
  84. GRB 200705A: Fermi GBM Final Real-time Localization
  85. GRB 200703B: Insight-HXMT/HE detection
  86. GRB 200703B: AstroSat CZTI detection
  87. GRB 200703B: Fermi GBM Final Real-time Localization
  88. GRB 200703A: Fermi GBM Final Real-time Localization
  89. Fermi GRB 200702A: Global MASTER-Net observations report
  90. GRB 200702A: Fermi GBM Final Real-time Localization
  91. Fermi-GBM Sub-Threshold Detection of GRB 200701A
  92. GRB 200630B: Fermi GBM Final Localization
  93. GRB 200630A: Fermi GBM detection
  94. GRB 200629A: AstroSat CZTI detection
  95. GRB 200630A: Swift detection of a burst
  96. Fermi trigger No 615174580: Global MASTER-Net observations report
  97. Fermi GRB 200629A: Global MASTER-Net observations report
  98. GRB 200629A: Fermi GBM Final Real-time Localization
  99. GRB 200629A: BALROG localization (Fermi Trigger 615127794 / GRB 200629535)
  100. GRB 200623A: Further MMTCam Observations of XRT Source #3

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