Definition of proper motion in English:

proper motion

noun

mass nounAstronomy

The part of the apparent motion of a fixed star that is due to its actual movement in space relative to the sun.
〔天文〕自转，自行
Example sentencesExamples
- His work on applying trigonometric methods to astronomical problems led him to note correctly that comets displayed a proper motion against the background stars.
- At perihelion, when proper motion reaches its maximum, it exceeds the diurnal motion, and the Sun turns slowly retrograde for a week.
- In 1710, using Ptolemy's catalogue, Halley deduced that the stars must have small motions of their own and he was able to detected this proper motion in three stars.
- Because the l = 1 dipole term is usually subtracted out from the data because it has large components due to our proper motion with respect to the cosmic background radiation.
- His method of selecting a star was based on his own data for he chose the star which had the greatest proper motion of all the stars he had studied, correctly deducing that this would mean that the star was nearby.

Definition of proper motion in US English:

proper motion

nounˈpräpər ˈmōSHən

Astronomy

The part of the apparent motion of a fixed star that is due to its actual movement in space relative to the sun.
〔天文〕自转，自行
Example sentencesExamples
- His work on applying trigonometric methods to astronomical problems led him to note correctly that comets displayed a proper motion against the background stars.
- In 1710, using Ptolemy's catalogue, Halley deduced that the stars must have small motions of their own and he was able to detected this proper motion in three stars.
- At perihelion, when proper motion reaches its maximum, it exceeds the diurnal motion, and the Sun turns slowly retrograde for a week.
- Because the l = 1 dipole term is usually subtracted out from the data because it has large components due to our proper motion with respect to the cosmic background radiation.
- His method of selecting a star was based on his own data for he chose the star which had the greatest proper motion of all the stars he had studied, correctly deducing that this would mean that the star was nearby.

词汇	proper motion
释义	Definition of proper motion in English: proper motion noun mass nounAstronomy The part of the apparent motion of a fixed star that is due to its actual movement in space relative to the sun. 〔天文〕自转，自行 Example sentencesExamples His work on applying trigonometric methods to astronomical problems led him to note correctly that comets displayed a proper motion against the background stars. At perihelion, when proper motion reaches its maximum, it exceeds the diurnal motion, and the Sun turns slowly retrograde for a week. In 1710, using Ptolemy's catalogue, Halley deduced that the stars must have small motions of their own and he was able to detected this proper motion in three stars. Because the l = 1 dipole term is usually subtracted out from the data because it has large components due to our proper motion with respect to the cosmic background radiation. His method of selecting a star was based on his own data for he chose the star which had the greatest proper motion of all the stars he had studied, correctly deducing that this would mean that the star was nearby. Definition of proper motion in US English: proper motion nounˈpräpər ˈmōSHən Astronomy The part of the apparent motion of a fixed star that is due to its actual movement in space relative to the sun. 〔天文〕自转，自行 Example sentencesExamples His work on applying trigonometric methods to astronomical problems led him to note correctly that comets displayed a proper motion against the background stars. In 1710, using Ptolemy's catalogue, Halley deduced that the stars must have small motions of their own and he was able to detected this proper motion in three stars. At perihelion, when proper motion reaches its maximum, it exceeds the diurnal motion, and the Sun turns slowly retrograde for a week. Because the l = 1 dipole term is usually subtracted out from the data because it has large components due to our proper motion with respect to the cosmic background radiation. His method of selecting a star was based on his own data for he chose the star which had the greatest proper motion of all the stars he had studied, correctly deducing that this would mean that the star was nearby.
随便看	let someone in on let someone in on/into let someone in on/into let someone in on something let someone into let someone know let someone know let someone loose let someone off let someone off let someone off (the hook) let someone off the hook let someone off with let someone out let someone out let someone see how it feels let someone smooth one's ruffled feathers let someone/something be let someone/something be let someone/something go let someone/something go let someone/something loose let someone/something loose let someone use let something be