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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"
  1. X-ray transient EP240315a: e-MERLIN radio observations
  2. X-ray transient EP240315a: Ondrejov D50 optical limit
  3. Transient EPW20240219aa: REM optical/NIR further observations
  4. Fermi trigger No 733092476: Global MASTER-Net observations report
  5. GRB 240320A: Glowbug gamma-ray detection
  6. Fermi trigger No 732937833: Global MASTER-Net observations report
  7. GRB 240318A: Fermi GBM Observation
  8. Fermi GRB 240320A: Global MASTER-Net observations report
  9. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  10. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  11. Fermi trigger No 732657380: Global MASTER-Net observations report
  12. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  13. X-ray transient EP240315a: ATCA detection of radio counterpart
  14. GRB 240320A: Fermi GBM Final Real-time Localization
  15. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  16. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  17. Fermi Gamma-ray Burst Monitor trigger 732299243/240316686 is not a GRB
  18. X-ray transient EP 240315a: Chandra observations
  19. X-ray transient EP240315a: GTC/HiPERCAM photometry
  20. X-ray transient EP240315a: MeerKAT radio detection
  21. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  22. GRB 240318A: Glowbug gamma-ray detection
  23. GRB 240317C: Glowbug gamma-ray detection
  24. GRB 240318B: Glowbug gamma-ray detection
  25. X-ray transient EP240315a: PRIME near infrared detection
  26. GRB 240317B: Fermi GBM Observation
  27. X-ray transient EP240315a: 3.6 m TNG NIR detection
  28. Swift satellite in safe mode
  29. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  30. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  31. Fermi GRB 240318A: Global MASTER-Net observations report
  32. GRB 240318A: Fermi GBM Final Real-time Localization
  33. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  34. GRB 240317A: AstroSat CZTI detection
  35. GRB 240315B: AstroSat CZTI detection
  36. X-ray transient EP240315a: Kitab observatory optical upper limitns
  37. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  38. Fermi GRB 240317B: Global MASTER-Net observations report
  39. Fermi GRB 240317A: Global MASTER-Net observations report
  40. GRB 240317B: Fermi GBM Final Real-time Localization
  41. X-ray transient EP240315a: orphan FXT?
  42. GRB 240317A: Fermi GBM Final Real-time Localization
  43. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  44. X-ray transient EP240315a: GROND J-band detection
  45. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  46. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  47. Fermi trigger No 732299243: Global MASTER-Net observations report
  48. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  49. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  50. Einstein Probe detected of a fast X-ray transient EP240315a
  51. GRID detection of GRB 240306A
  52. Changes to the Fermi-GBM Triggering Thresholds
  53. Swift Triggers 1220155, 1220156, 1220157, 1220158, 1220160 and 1220161 were not astrophysical
  54. GRB 240315A: Fermi GBM Final Real-time Localization
  55. Swift Triggers 1220093, 1220094, 1220095 and 1220096 are not astrophysical
  56. Swift Triggers 1220090, 1220091 and 1220092 are not astrophysical
  57. Fermi GRB 240314A: Global MASTER-Net observations report
  58. GRB 240314A: Fermi GBM Final Real-time Localization
  59. GRB240204A: VIRT optical upper limit
  60. GRB 240312A: Glowbug gamma-ray detection
  61. Swift triggers 1219917, 1219917 and 1219922 were not astrophysical
  62. Swift Trigger 1219909 and 1219910 are not a astrophysical
  63. Swift Trigger 1219905 is not a GRB
  64. GRB 240312A: GECAM detection of a long burst
  65. Swift Trigger 1219874 is not astrophysical
  66. GRB 240303C: VZLUSAT-2 detection
  67. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  68. Fermi trigger No 731839490: Global MASTER-Net observations report
  69. Fermi-LAT gamma-ray observations of IceCube-240307A
  70. GRB 240310B: Glowbug gamma-ray detection
  71. Fermi GRB 240310A: Global MASTER-Net observations report
  72. Swift GRB240309.61: Global MASTER-Net observations report
  73. GRB 240310A: Fermi GBM Final Real-time Localization
  74. GRB 240309A: MAXI/GSC detection
  75. Swift Trigger 1219325 is not a GRB
  76. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  77. GRID detection of GRB 240229A (Updated Report)
  78. GRID detection of GRB 240229A
  79. GRB 240308A: Fermi GBM Final Localization
  80. Fermi trigger No 731571927: Global MASTER-Net observations report
  81. GRB 231215A: further radio observations with the VLA
  82. GRB 240306A: Fermi GBM observation
  83. IceCube-240307A - IceCube observation of a high-energy neutrino candidate track-like event
  84. GRB 240229A: Glowbug gamma-ray detection
  85. GRB 240227A (short): Glowbug gamma-ray detection
  86. IceCube Alert 240307.32: Global MASTER-Net observations report
  87. GRB 240229A: GRBAlpha detection
  88. Konus-Wind detection of GRB 231118A
  89. GRB 240306A: AstroSat CZTI detection
  90. Fermi GRB 240306A: Global MASTER-Net observations report
  91. Fermi GRB 240305A: Global MASTER-Net observations report
  92. GRB 240306A: Swift/BAT-GUANO detection of a burst
  93. GRB 240305A: Fermi GBM observation
  94. Fermi-LAT gamma-ray observations of IceCube-240229A
  95. GRB 240305C: AstroSat CZTI detection of a short burst
  96. GRB 240306A: Fermi GBM Final Real-time Localization
  97. Swift GRB240305.18: Global MASTER-Net observations report
  98. Swift GRB240305.16: Global MASTER-Net observations report
  99. Fermi GRB 240305C: Global MASTER-Net observations report
  100. GRB 240305C: Fermi GBM Final Real-time Localization

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