annual parallax

Perhaps better telescopes, in future times, would find an annual parallax.

The annual parallax of this star is measured to be around 0.62 milli-arc-seconds.

Measurement of annual parallax was the first reliable way to determine the distances to the closest stars.

No such "annual parallax" had been found.

The annual parallax shift of this object is much smaller than the measurement error, making distance estimates by that means unreliable.

Annual parallax is normally measured by observing the position of a star at different times of the year as the Earth moves through its orbit.

Because of the Earth's orbit about the Sun, this system has an annual parallax shift of 4.18 mas.

The parsec (3.26 light-years) is defined as the distance for which the annual parallax is 1 arcsecond.

The orbital motion of the Earth causes this star to undergo an annual parallax shift of 17.77 milliarcseconds.

The long-debated annual parallax was at last discovered-not by better arguments, but by better instruments.

This was not mere scientific caution and restraint, a reluctance to shift a paradigm until compelling evidence, such as the annual parallax, was available.

In the Copernican theory, the stars had to lie at vast distances from Earth in order to explain why no annual parallax was seen among them.

In 1838, Friedrich Bessel made the first successful measurements of annual parallax for the star 61 Cygni using a heliometer.

Astrometric radial velocity is the radial velocity as determined by astrometric observations (for example, a secular change in the annual parallax).

Indeed it also seems it was even the only planetary model that was generally observationally tenable, given the twin failures to find any stellar annual parallax nor any Martian daily parallax at that time.

A star's direction remains nearly fixed due to its vast distance, but its right ascension and declination do change gradually due to precession of the equinoxes and proper motion, and cyclically due to annual parallax.

Stellar parallax is most often measured using annual parallax, defined as the difference in position of a star as seen from the Earth and Sun, i. e. the angle subtended at a star by the mean radius of the Earth's orbit around the Sun.

Based upon an annual parallax shift of 21.32 0.81 mas, This is an A-type main sequence star with a stellar classification of A4 Vm; the 'm' suffix indicating that abnormal abundances of heavier elements appear in the star's spectrum, making this an Am star.