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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"

4714 results found.

  1. Fermi trigger No 732657380: Global MASTER-Net observations report
  2. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  3. X-ray transient EP240315a: ATCA detection of radio counterpart
  4. GRB 240318A: Glowbug gamma-ray detection
  5. GRB 240317C: Glowbug gamma-ray detection
  6. GRB 240318B: Glowbug gamma-ray detection
  7. X-ray transient EP240315a: PRIME near infrared detection
  8. X-ray transient EP240315a: 3.6 m TNG NIR detection
  9. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  10. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  11. Fermi GRB 240318A: Global MASTER-Net observations report
  12. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  13. GRB 240317A: AstroSat CZTI detection
  14. GRB 240315B: AstroSat CZTI detection
  15. X-ray transient EP240315a: Kitab observatory optical upper limitns
  16. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  17. Fermi GRB 240317B: Global MASTER-Net observations report
  18. Fermi GRB 240317A: Global MASTER-Net observations report
  19. Fermi trigger No 732299243: Global MASTER-Net observations report
  20. Einstein Probe detected of a fast X-ray transient EP240315a
  21. GRID detection of GRB 240306A
  22. Fermi GRB 240314A: Global MASTER-Net observations report
  23. GRB 240312A: Glowbug gamma-ray detection
  24. GRB 240312A: GECAM detection of a long burst
  25. GRB 240303C: VZLUSAT-2 detection
  26. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  27. Fermi trigger No 731839490: Global MASTER-Net observations report
  28. Fermi-LAT gamma-ray observations of IceCube-240307A
  29. GRB 240310B: Glowbug gamma-ray detection
  30. Fermi GRB 240310A: Global MASTER-Net observations report
  31. Swift GRB240309.61: Global MASTER-Net observations report
  32. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  33. Fermi trigger No 731571927: Global MASTER-Net observations report
  34. IceCube Alert 240307.32: Global MASTER-Net observations report
  35. GRB 240306A: AstroSat CZTI detection
  36. Fermi GRB 240306A: Global MASTER-Net observations report
  37. Fermi GRB 240305A: Global MASTER-Net observations report
  38. GRB 240306A: Swift/BAT-GUANO detection of a burst
  39. GRB 240305C: AstroSat CZTI detection of a short burst
  40. Swift GRB240305.18: Global MASTER-Net observations report
  41. Swift GRB240305.16: Global MASTER-Net observations report
  42. Fermi GRB 240305C: Global MASTER-Net observations report
  43. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  44. GRB 240305B: Fermi GBM Final Localization
  45. Fermi trigger No 731303574: Global MASTER-Net observations report
  46. GRB 240303B: VZLUSAT-2 detection
  47. IPN triangulation of GRB 240229A
  48. Swift Trigger 1218696: Another trigger on Swift J151857.0-572147
  49. Transient EPW20240219aa: Optical observations with LDT
  50. GRB 240303B: Fermi GBM Detection
  51. Fermi trigger No 731161136: Global MASTER-Net observations report
  52. GRB 240303C: BALROG localization (Fermi Trigger 731189113 / GRB 240303837)
  53. Swift GRB 240303A: Global MASTER-Net observations report
  54. GRB 240303B: BALROG localization (Fermi Trigger 731161136 / GRB 240303513)
  55. GRB 240303B: Fermi GBM Final Localization
  56. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  57. GRB 240229A: DDOTI Upper Limits on the Afterglow
  58. GRB 240225B: further SAO RAS optical observations
  59. Fermi GRB 240229A: Global MASTER-Net observations report
  60. IceCube Alert 240229.66: Global MASTER-Net observations report
  61. GRB 240225B: Mondy afterglow observations
  62. Fermi GRB 240227A: Global MASTER-Net observations report
  63. GRB 240216A: GRBAlpha detection
  64. Fermi trigger No 729914426: Global MASTER-Net observations report
  65. GRB 240214A/1H 0451-560: MAXI/GSC detection
  66. GRB 240209A: GOTO optical counterpart candidate
  67. Fermi trigger No 729152364: Global MASTER-Net observations report
  68. Fermi trigger No 729012023: Global MASTER-Net observations report
  69. Fermi trigger No 728749569: Global MASTER-Net observations report
  70. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  71. GRB 240128A: MAXI/GSC detection
  72. GRB 240123A: further SAO RAS optical observations
  73. GRB 240123A: SAO RAS optical observations
  74. GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
  75. GRB 240123B: Fermi GBM Final Real-time Localization
  76. GRB 240122A: MAXI/GSC detection
  77. GRB 240115A: Fermi GBM Observation
  78. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  79. Fermi GRB 240115A: Global MASTER-Net observations report
  80. GRB 240115A: Fermi GBM Final Real-time Localization
  81. GRB 240112C: SAO RAS optical observations
  82. GRB 231215A: radio detection with the VLA
  83. GRB 240107A: MAXI/GSC detection
  84. Fermi trigger No 726347794: Global MASTER-Net observations report
  85. GRB 240102C: AstroSat CZTI detection
  86. Fermi trigger No 725806648: Global MASTER-Net observations report
  87. GRB 231222B: GRBAlpha detection
  88. LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
  89. Fermi trigger No 724781422: Global MASTER-Net observations report
  90. Fermi trigger No 724278269: Global MASTER-Net observations report
  91. IceCube Alert 231211.03: Global MASTER-Net observations report
  92. Fermi trigger No 723581802: Global MASTER-Net observations report
  93. Fermi trigger No 723435916: Global MASTER-Net observations report
  94. Fermi trigger No 723326169: Global MASTER-Net observations report
  95. IceCube-231202A: Upper limits from a search for additional neutrino events in IceCube
  96. Fermi trigger No 723412808: Global MASTER-Net observations report
  97. GRB 231203A: Fermi GBM Observation
  98. GRB 231204A: Fermi GBM Final Real-time Localization
  99. Fermi trigger No 723279695: Global MASTER-Net observations report
  100. GRB 231129B: MAXI/GSC detection

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