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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"

5401 results found.

  1. GRB 240315B: AstroSat CZTI detection
  2. X-ray transient EP240315a: Kitab observatory optical upper limitns
  3. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  4. Fermi GRB 240317B: Global MASTER-Net observations report
  5. Fermi GRB 240317A: Global MASTER-Net observations report
  6. Fermi trigger No 732299243: Global MASTER-Net observations report
  7. Einstein Probe detected of a fast X-ray transient EP240315a
  8. GRID detection of GRB 240306A
  9. Fermi GRB 240314A: Global MASTER-Net observations report
  10. GRB 240312A: Glowbug gamma-ray detection
  11. GRB 240312A: GECAM detection of a long burst
  12. GRB 240303C: VZLUSAT-2 detection
  13. GRB 240310A: MASTER OT J200702.72-263928.7 inside 3sigma
  14. Fermi trigger No 731839490: Global MASTER-Net observations report
  15. Fermi-LAT gamma-ray observations of IceCube-240307A
  16. GRB 240310B: Glowbug gamma-ray detection
  17. Fermi GRB 240310A: Global MASTER-Net observations report
  18. Swift GRB240309.61: Global MASTER-Net observations report
  19. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  20. Fermi trigger No 731571927: Global MASTER-Net observations report
  21. IceCube Alert 240307.32: Global MASTER-Net observations report
  22. GRB 240306A: AstroSat CZTI detection
  23. Fermi GRB 240306A: Global MASTER-Net observations report
  24. Fermi GRB 240305A: Global MASTER-Net observations report
  25. GRB 240306A: Swift/BAT-GUANO detection of a burst
  26. GRB 240305C: AstroSat CZTI detection of a short burst
  27. Swift GRB240305.18: Global MASTER-Net observations report
  28. Swift GRB240305.16: Global MASTER-Net observations report
  29. Fermi GRB 240305C: Global MASTER-Net observations report
  30. GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
  31. GRB 240305B: Fermi GBM Final Localization
  32. Fermi trigger No 731303574: Global MASTER-Net observations report
  33. GRB 240303B: VZLUSAT-2 detection
  34. IPN triangulation of GRB 240229A
  35. Swift Trigger 1218696: Another trigger on Swift J151857.0-572147
  36. Transient EPW20240219aa: Optical observations with LDT
  37. GRB 240303B: Fermi GBM Detection
  38. Fermi trigger No 731161136: Global MASTER-Net observations report
  39. GRB 240303C: BALROG localization (Fermi Trigger 731189113 / GRB 240303837)
  40. Swift GRB 240303A: Global MASTER-Net observations report
  41. GRB 240303B: BALROG localization (Fermi Trigger 731161136 / GRB 240303513)
  42. GRB 240303B: Fermi GBM Final Localization
  43. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  44. GRB 240229A: DDOTI Upper Limits on the Afterglow
  45. GRB 240225B: further SAO RAS optical observations
  46. Fermi GRB 240229A: Global MASTER-Net observations report
  47. IceCube Alert 240229.66: Global MASTER-Net observations report
  48. GRB 240225B: Mondy afterglow observations
  49. Fermi GRB 240227A: Global MASTER-Net observations report
  50. GRB 240216A: GRBAlpha detection
  51. Fermi trigger No 729914426: Global MASTER-Net observations report
  52. GRB 240214A/1H 0451-560: MAXI/GSC detection
  53. GRB 240209A: GOTO optical counterpart candidate
  54. Fermi trigger No 729152364: Global MASTER-Net observations report
  55. Fermi trigger No 729012023: Global MASTER-Net observations report
  56. Fermi trigger No 728749569: Global MASTER-Net observations report
  57. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  58. GRB 240128A: MAXI/GSC detection
  59. GRB 240123A: further SAO RAS optical observations
  60. GRB 240123A: SAO RAS optical observations
  61. GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
  62. GRB 240123B: Fermi GBM Final Real-time Localization
  63. GRB 240122A: MAXI/GSC detection
  64. GRB 240115A: Fermi GBM Observation
  65. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  66. Fermi GRB 240115A: Global MASTER-Net observations report
  67. GRB 240115A: Fermi GBM Final Real-time Localization
  68. GRB 240112C: SAO RAS optical observations
  69. GRB 231215A: radio detection with the VLA
  70. GRB 240107A: MAXI/GSC detection
  71. Fermi trigger No 726347794: Global MASTER-Net observations report
  72. GRB 240102C: AstroSat CZTI detection
  73. Fermi trigger No 725806648: Global MASTER-Net observations report
  74. GRB 231222B: GRBAlpha detection
  75. LIGO/Virgo/KAGRA S231223j: Identification of a GW compact binary merger candidate
  76. Fermi trigger No 724781422: Global MASTER-Net observations report
  77. Fermi trigger No 724278269: Global MASTER-Net observations report
  78. IceCube Alert 231211.03: Global MASTER-Net observations report
  79. Fermi trigger No 723581802: Global MASTER-Net observations report
  80. Fermi trigger No 723435916: Global MASTER-Net observations report
  81. Fermi trigger No 723326169: Global MASTER-Net observations report
  82. IceCube-231202A: Upper limits from a search for additional neutrino events in IceCube
  83. Fermi trigger No 723412808: Global MASTER-Net observations report
  84. GRB 231203A: Fermi GBM Observation
  85. GRB 231204A: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 723279695: Global MASTER-Net observations report
  87. GRB 231129B: MAXI/GSC detection
  88. Fermi trigger No 722507896: Global MASTER-Net observations report
  89. Fermi trigger No 722462310: Global MASTER-Net observations report
  90. Fermi trigger No 722400249: Global MASTER-Net observations report
  91. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  92. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  93. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  94. GRB 231117A: GECAM-C detection
  95. GRB 231117A: GRBAlpha detection
  96. GRB 231117A: REM optical and NIR early-time observations
  97. GRB 231117A (short): Glowbug gamma-ray detection
  98. GRB 231117A: ATLAS non-detection of an optical counterpart
  99. Konus-Wind detection of GRB 231117A (short/hard)
  100. GRB 231115A: optical observations from INAF observatories

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