what is an astronomical unit, a parsec or some other unit of measurment?

Question

I know a parsec is the distance light travels in one year. is the parsec the only astronomical unit used in astronomy and astrophysics?

Answer 1

Hi there!

Let me set the parameters for my answers first:
The astronomical unit (AU or au or a.u. or sometimes ua) is a unit of length. It is approximately equal to the mean distance between Earth and Sun. The currently accepted value of the AU is 149 597 870 691 ± 30 metres (about 150 million kilometres or 93 million miles).

The symbol "ua" is recommended by the Bureau International des Poids et Mesures, but in the United States and other anglophone countries the reverse usage is more common. The International Astronomical Union recommends "au" and international standard ISO 31-1 uses "AU".

The parsec (symbol pc) is a unit of length used in astronomy. It stands for "parallax of one arc second".

It is based on the method of trigonometric parallax, one of the most ancient and standard methods of determining stellar distances. The parallax of a star is half of the angular distance a star appears to move against the celestial sphere due to the orbit of the Earth around the Sun.

As to conversion of one unit to another, some conversion factors are:

1 AU = 149 597 870.691 ± 0.030 km ≈ 92 955 807 miles ≈ 8.317 light minutes ≈ 499 light-seconds
1 light-second ≈ 0.002 AU
1 light-minute ≈ 0.120 AU
1 light-hour ≈ 7.214 AU
1 light-day ≈ 173 AU
1 light-year ≈ 63 241 AU
1 pc ≈ 206 265 AU

Some Common Distance Units:
Light Year: the distance that light travels in one year (9.46 x 10^17 cm).

Parsec (pc): 3.26 light years (or 3.086 x 10^18 cm).; also kiloparsec (kpc) = 1000 parsecs and megaparsec (Mpc) = 1,000,000 parsecs.

Astronomical Unit (AU): the average separation of the earth and the sun (1.496 x 10^13 cm).


I hope this helps you with your question.

Answer 2

No, they are NOT the same same. A parsec (parallel second) is 3.1 × 10^13 km and an AU (astronomical unit) is only about 1.5 x 10^8 km. That's 200,00 times smaller than a parsec! The only other common measurment used in astronomy is the light year which is 9.5 x 10^12 km.

Answer 3

An astronomical unit (AU) is the mean radius of Earth's orbit (about 150 million km).

A parsec (pc) is the distance at which 1AU subtends an angle of one arc-second. The name is a contraction of parallax-second. 1 pc= 206,265 AU or not quite 31 trillion km.

A light year is the distance light travels in one year; a parsec is about 3.26 light years.

Though light year is widely used in popular science literature, astronomers generally prefer to use parsecs.

Answer 4

An astronomical unit is an astronomical unit. It is the distance between the Earth and the Sun which is approximitaly 92,800,000 miles. A parsec is about 3.2637982 light-years.

Answer 5

1 Parsec = 3.08568025 × 10^16 meters

a Parsec is not the same as a light year

Answer 6

1 AU = Our solar Syst end to end
Oops I Stand corrected 1 AU = 93 Million Miles. Dist Of earth From Sun
1 Parsec = Dist Travelled By Light In 3. 26 yrs

Answer 7

An AU is the distance from the Earth to the Sun (about 93 million miles).

Answer 8

What Is An Astronomical

Answer 9

1 light year = 5.8-trillion miles
3.26 light years = 1 parsec
3,261,688 light years = 1 megaparsec

1 astronomical unit = 92,957,130.36 miles

Answer 10

i hope you are asking this cus you are taking astronomy classes. lol i know i asked those questions all the time, when i was taking my astronomy classes.. good luck and i wouldnt know if they only use it only in astronomy, i would think so though.