radial velocity
1
7.9
- noun
- /ˈreɪdiəl vɪˈlɒsɪti/
- Specialized
:
velocidad radial
- The component of the velocity of a star in space along the line of sight, the radial velocity, can be determined directly, in kilometers per second, from the Doppler shift of the spectral lines.
- measuring radial velocity
- radial velocity of stars
Examples
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And the shift of these absorption lines, due to the Doppler effect, tells us how fast the star is moving along our line of sight (i.e., the radial velocity).
Academic text (2000) -
The astronomers calculated the radial velocity of the star to determine how fast it was moving toward Earth.
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All right, so this is a radial velocity curve of some star.
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Over the next four decades, he would come to dominate the field of radial velocity measurement.
Academic text (1992) -
And this radial velocity method essentially provides the mass of the planet, and the transit method provides the radius.
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Traditionally, a star's wobble has been used to measure mass in what's known as the radial velocity method.
Blog text (5) -
This motion shows up as periodic variations in the white dwarf's radial velocity.
Academic text (1992) -
In addition to a four-day period derived from the star's radial velocity data, they observed a longer-period trend that suggested the presence of an additional planet.
Academic text (2000) -
She monitors the radial velocities of some 300 stars from Lick Observatory.
Academic text (2000) -
To find out, astronomers today measure positions and radial velocities of galaxies, which we currently regard as the building blocks of the observable universe.
Academic text (1991)
Surface Forms
Morphology
The meaning is directly compositional: 'radial' specifies direction along a radius and 'velocity' denotes rate of motion, so a learner who knows both words can infer it means the velocity along the line from the observer (toward or away). Although 'radial' is somewhat technical, the modifier+noun structure is regular and cross-linguistically common, making the sense predictable from the parts.
Etymology
Radial velocity combines radial (along a line from a centre) and velocity ('speed'). Imagine a car driving straight toward you or straight away from you; the radial velocity is the part of its speed that points along your view. That's why the term means how fast something is moving 'toward' or 'away' from you.