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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').

774 results found.

  1. GRB 240514E: A possible candidate BD-21 1074
  2. MAXI GRB240514.78: Global MASTER-Net observations report
  3. GRB 240514E: MAXI/GSC detection of a probable afterglow
  4. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  5. LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
  6. GRB 240309A: MAXI/GSC detection
  7. GRB 240225B: Swift-XRT afterglow detection
  8. GRB 240225B: Glowbug gamma-ray detection
  9. GRB 240225B: Swift ToO observations
  10. Konus-Wind detection of GRB 240225B (long)
  11. GRB 240225B: VLT/X-shooter redshift
  12. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  13. GRB 240225B: 3.6m DOT observation
  14. GRB 240225B: NOT optical observations
  15. GRB 240225B: Nanshan/HMT optical afterglow detection
  16. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  17. GRB 240225B: Swift-XRT observations
  18. GRB 240225B: GOTO detection of a candidate optical afterglow
  19. GRB 240225B: AstroSat CZTI detection
  20. GRB 240225B: Tiled Swift observations
  21. GRB 240225B: MAXI/GSC detection
  22. GRB 240128A: Further Swift-XRT observations
  23. GRB 240214A: Tiled Swift observations
  24. GRB 240214A/1H 0451-560: MAXI/GSC detection
  25. GRB 240128A: Glowbug gamma-ray detection
  26. GRB 240128A: Swift-XRT observations
  27. GRB 240128A: GRBAlpha detection
  28. GRB 240128A: Tiled Swift observations
  29. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  30. GRB 240128A: MAXI/GSC detection
  31. GRB 240122A: ATCA detection of radio counterpart
  32. GRB240122A: PRIME near infrared detection
  33. GRB 240122A: Swift/UVOT Upper Limits
  34. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  35. Swift GRB240123.46: Global MASTER-Net observations report
  36. GRB 240122A: Swift-XRT afterglow detection
  37. GRB 240122A: VLT/X-shooter redshift confirmation
  38. GRB 240122A: Redshift from OSIRIS+/GTC
  39. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  40. GRB 240122A: GOTO optical counterpart candidate
  41. GRB 240122A: Tiled Swift observations
  42. GRB 240122A: MAXI/GSC detection
  43. GRB 240107A: VZLUSAT-2 detection
  44. GRB 240114A: MAXI/GSC detection
  45. GRB 240107A: AstroSat CZTI detection
  46. GRB 240107A: MAXI/GSC detection
  47. IPN triangulation of GRB 231129C
  48. GRB 231129C: ASIM MXGS observation and localization
  49. Konus-Wind detection of GRB 231129C
  50. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  51. GRB 231129B: Swift-XRT observations
  52. GRB 231129C: AGILE detection
  53. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  54. GRB 231129C: MASTER OT detection
  55. GRB 231129C: Fermi-LAT detection
  56. GRB 231129C: GRBAlpha detection
  57. GRB 231129C: Glowbug gamma-ray detection
  58. GRB 231129C: GECAM-B detection of a bright burst
  59. GRB 231129C: AstroSat CZTI detection
  60. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  61. GRB 231129C: Fermi GBM Observation of a very bright GRB
  62. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  63. GRB 231129C: MAXI/GSC detection
  64. GRB 231129B: Tiled Swift observations
  65. GRB 231129B: MAXI/GSC detection
  66. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  67. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  68. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  70. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  71. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  72. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  73. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  74. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  75. LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
  76. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  77. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  78. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  79. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  80. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  81. Konus-Wind detection of GRB 220623A
  82. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  83. GRB 230623A: Swift-XRT observations
  84. GRB 230623A: Tiled Swift observations
  85. MAXI GRB 230623A: MASTER optical observations
  86. GRB 230623A: Tiled Swift observations
  87. GRB 230623A: MAXI/GSC detection
  88. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  89. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 230520A: MAXI/GSC detection
  91. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  92. GRB 230510B: Fermi GBM detection
  93. GRB 230510B: AstroSat CZTI detection
  94. GRB 230510B: CALET Gamma-Ray Burst Monitor detection
  95. GRB 230510B: MAXI/GSC detection
  96. MAXI GRB230408.82: Global MASTER-Net observations report
  97. GRB 230307A: soft X-ray detection with LEIA
  98. GRB 230307A: MAXI/GSC upper limit
  99. GRB 230220A: Correction to GCN 33352
  100. GRB 230220A: MAXI/GSC detection

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