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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. Fermi trigger No 733366352: Global MASTER-Net observations report
  2. Fermi GRB 240329A: Global MASTER-Net observations report
  3. GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
  4. GRB 240329A: Fermi GBM Final Real-time Localization
  5. Fermi GRB 240328B: Global MASTER-Net observations report
  6. Fermi GRB 240328A: Global MASTER-Net observations report
  7. X-ray transient EP240315a: continued ATCA monitoring
  8. IceCube-240327B: No candidates from the Zwicky Transient Facility
  9. GRB 240328C: Glowbug gamma-ray detection
  10. GRB 240328B: Fermi GBM Final Real-time Localization
  11. GRB 240328A: Fermi GBM Final Real-time Localization
  12. IceCube Alert 240327.68: Global MASTER-Net observations report
  13. IceCube-240327B - IceCube observation of a high-energy neutrino candidate track-like event
  14. IceCube-240327A - IceCube observation of a high-energy neutrino candidate track-like event
  15. X-ray transient EP 240315a: Second epoch Chandra observations
  16. Fermi trigger No 733097506: Global MASTER-Net observations report
  17. X-ray transient EP240315a: e-MERLIN radio observations
  18. X-ray transient EP240315a: Ondrejov D50 optical limit
  19. Transient EPW20240219aa: REM optical/NIR further observations
  20. Fermi trigger No 733092476: Global MASTER-Net observations report
  21. GRB 240320A: Glowbug gamma-ray detection
  22. Fermi trigger No 732937833: Global MASTER-Net observations report
  23. GRB 240318A: Fermi GBM Observation
  24. Fermi GRB 240320A: Global MASTER-Net observations report
  25. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  26. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  27. Fermi trigger No 732657380: Global MASTER-Net observations report
  28. GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  29. X-ray transient EP240315a: ATCA detection of radio counterpart
  30. GRB 240320A: Fermi GBM Final Real-time Localization
  31. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  32. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  33. Fermi Gamma-ray Burst Monitor trigger 732299243/240316686 is not a GRB
  34. X-ray transient EP 240315a: Chandra observations
  35. X-ray transient EP240315a: GTC/HiPERCAM photometry
  36. X-ray transient EP240315a: MeerKAT radio detection
  37. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  38. GRB 240318A: Glowbug gamma-ray detection
  39. GRB 240317C: Glowbug gamma-ray detection
  40. GRB 240318B: Glowbug gamma-ray detection
  41. X-ray transient EP240315a: PRIME near infrared detection
  42. GRB 240317B: Fermi GBM Observation
  43. X-ray transient EP240315a: 3.6 m TNG NIR detection
  44. Swift satellite in safe mode
  45. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  46. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  47. Fermi GRB 240318A: Global MASTER-Net observations report
  48. GRB 240318A: Fermi GBM Final Real-time Localization
  49. GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
  50. GRB 240317A: AstroSat CZTI detection
  51. GRB 240315B: AstroSat CZTI detection
  52. X-ray transient EP240315a: Kitab observatory optical upper limitns
  53. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  54. Fermi GRB 240317B: Global MASTER-Net observations report
  55. Fermi GRB 240317A: Global MASTER-Net observations report
  56. GRB 240317B: Fermi GBM Final Real-time Localization
  57. X-ray transient EP240315a: orphan FXT?
  58. GRB 240317A: Fermi GBM Final Real-time Localization
  59. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  60. X-ray transient EP240315a: GROND J-band detection
  61. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  62. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  63. Fermi trigger No 732299243: Global MASTER-Net observations report
  64. AT2024eju: followup observations with Liverpool Telescope suggest a fading transient
  65. X-ray transient EP240315a: ATLAS detection of a possible optical counterpart AT2024eju
  66. Einstein Probe detected of a fast X-ray transient EP240315a
  67. GRID detection of GRB 240306A
  68. Changes to the Fermi-GBM Triggering Thresholds
  69. Swift Triggers 1220155, 1220156, 1220157, 1220158, 1220160 and 1220161 were not astrophysical
  70. GRB 240315A: Fermi GBM Final Real-time Localization
  71. Swift Triggers 1220093, 1220094, 1220095 and 1220096 are not astrophysical
  72. Swift Triggers 1220090, 1220091 and 1220092 are not astrophysical
  73. Fermi GRB 240314A: Global MASTER-Net observations report
  74. GRB 240314A: Fermi GBM Final Real-time Localization
  75. GRB240204A: VIRT optical upper limit
  76. GRB 240312A: Glowbug gamma-ray detection
  77. Swift triggers 1219917, 1219917 and 1219922 were not astrophysical
  78. Swift Trigger 1219909 and 1219910 are not a astrophysical
  79. Swift Trigger 1219905 is not a GRB
  80. GRB 240312A: GECAM detection of a long burst
  81. Swift Trigger 1219874 is not astrophysical
  82. GRB 240303C: VZLUSAT-2 detection
  83. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  84. Fermi trigger No 731839490: Global MASTER-Net observations report
  85. Fermi-LAT gamma-ray observations of IceCube-240307A
  86. GRB 240310B: Glowbug gamma-ray detection
  87. Fermi GRB 240310A: Global MASTER-Net observations report
  88. Swift GRB240309.61: Global MASTER-Net observations report
  89. GRB 240310A: Fermi GBM Final Real-time Localization
  90. GRB 240309A: MAXI/GSC detection
  91. Swift Trigger 1219325 is not a GRB
  92. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  93. GRID detection of GRB 240229A (Updated Report)
  94. GRID detection of GRB 240229A
  95. GRB 240308A: Fermi GBM Final Localization
  96. Fermi trigger No 731571927: Global MASTER-Net observations report
  97. GRB 231215A: further radio observations with the VLA
  98. GRB 240306A: Fermi GBM observation
  99. IceCube-240307A - IceCube observation of a high-energy neutrino candidate track-like event
  100. GRB 240229A: Glowbug gamma-ray detection

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