Question

Parsec is the unit of
A) Speed
B) Time
C) Distance
D) None of the above

Answer 1

Hint: The parsec is described as being identical to the length of the adjacent leg (opposite leg being \[1AU\]) of an incredibly elongated imaginary right triangle shape in space.

Complete step-by-step answer:
The dimensions on which this triangle is primarily based totally are its shorter leg, of length one astronomical unit, and the subtended angle in degree of the vertex opposite that leg, measuring one arcsecond. Applying the regulations of Mathematics i.e, trigonometry to all these values, the unit of the other leg side of the triangle (that is a parsec) may be derived.

One of the oldest techniques utilized by astronomers to calculate the gap to a star or a celestial body is to note the change in angle among measurements of the place of the star in the galaxy. The first measurement is taken from the Earth on one side of the Sun, and the other one is taken about half of a year later, while the Earth is on the opposite facet of the Sun. The distance among the two positions of the Earth while the two measurements that were taken is two times the gap among the Earth and the Sun.

A corollary states that a parsec is likewise the gap from which a disc one astronomical unit(\[AU\]) in diameter ought to be viewed for it to have an angular diameter value of one arcsecond (through setting the observer at a place\[D\] and a diameter of the disc on \[ES\]).

Mathematically, to calculate distance, given received angular measurements from units in arcsecond , the method might be in a Distance \[D\]
\[{D_{star}} = \dfrac{{{D_{earth - sun}}}}{{\tan \dfrac{\theta }{{3600}}}}\]

Therefore, the correct answer is option C. i.e, Distance.

Note: One parsec is about thirty trillion kilometers, or just over three light-years for approx value used in formula,
\[{\rm{1 parsec = 3}}{\rm{.086e + 16 m}}\]