From which two words is the unit name parsec (pc) constructed as a portmanteau?
Answer
Parallax and second
The term parsec is a derived unit specifically tailored for measuring interstellar distances using trigonometric parallax. It is a direct contraction of the terms parallax and second. Formally, a parsec is defined as the distance from the Earth where one astronomical unit subtends an angle of one arcsecond as observed from that location. This definition highlights its direct mathematical link to the geometric method (parallax) and the angular measurement (second) used to derive it, making it the preferred unit for professional astronomers employing these trigonometric techniques.
Related Questions
What exact, fixed value did the IAU establish for the Astronomical Unit in 2012?What physical quantity does the light-year (LY) measure, despite its naming convention?From which two words is the unit name parsec (pc) constructed as a portmanteau?Which measurement technique is appropriate for gauging the distance to the Moon or planets?What foundational measurement is required for calculating distances using trigonometric parallax for nearby stars?What type of celestial object has an intrinsic luminosity directly related to its period of variation?What unit becomes impractical for describing the vast distances between stars and galaxies?What crucial implication arises if the initial baseline AU value contained a historical error?What characteristic allows Type Ia Supernovae to function as useful standard candles?When modeling cosmic scale, if 1 AU equals 1 centimeter, how far away is Proxima Centauri (4.24 ly) in kilometers on that map?