The annual parallax of a star is the angle subtended at the star by the radius of the Earth’s orbit, one astronomical unit, seen perpendicular to the line of sight; it is the semi-major axis of the yearly ellipse the star appears to trace. The parsec () is the distance at which one astronomical unit subtends one second of arc:
বইগুলো এখনো বাংলা ভাষায় পাওয়া যায় না — ইংরেজি সংস্করণ দেখানো হচ্ছে।
Earth and Space Sciences · পরিভাষা
Annual parallax, parsec কী?
অন্য নাম: annual parallax · parsec