YOU SAID:
Only three Milky Way naked-eye supernova events have been observed during the last thousand years, though many have been seen in other galaxies using telescopes. The most recent directly observed supernova in the Milky Way was Kepler's Supernova in 1604, but the remnants of two more recent supernovae have also been found.
INTO JAPANESE
3 つだけ天の川の肉眼超新星イベントは、望遠鏡を使って他の銀河に多く見られたが、最後の千年の間に観察されています。天の川の最も最近の直接観測された超新星 1604 年のケプラーの超新星のだったが、2 つのより多くの最近の超新星の残骸も発見されています。
That didn't even make that much sense in English.