Sentence examples for stellar distance from inspiring English sources
Starlight often shows a small degree of polarization (a few percent), with the effect increasing with stellar distance.
He guided the design and construction of the Navy's 61-inch telescope in Flagstaff, Ariz., an important tool for stellar distance measurements.
The platinum standard for measuring stellar distance is parallax.
"Because the LMC is close and contains a significant number of different stellar distance indicators, hundreds of distance measurements using it have been recorded over the years," said team member Ian Thompson of the Carnegie Institution for Science in Washington, D.C. "Unfortunately, nearly all the determinations have systemic errors, with each method carrying its own uncertainties".
A specialist in positional astronomy, he did pioneering work in determining stellar distances with reflecting telescopes.
In this work Gregory also introduced estimation of stellar distances by photometric methods.
Stellar distances are commonly expressed by astronomers in parsecs (pc), kiloparsecs, or megaparsecs.
(1 pc = 3.086 × 1018 cm, or about 3.26 light-years [1.92 × 1013 miles].) Distances can be measured out to around a kiloparsec by trigonometric parallax (see star: Determining stellar distances).
Observations with an interferometer (an instrument that measures the angle subtended by the diameter of a star at the observer's position), combined with parallax measurements (which yield a star's distance; see below Determining stellar distances), give sizes of 12 and 22 solar radii for Arcturus and Aldebaran A. Betelgeuse and Antares A are examples of supergiant stars.
"Knowing stellar distances is extremely important for many fields of astrophysics," Prusti says.
If the intrinsic luminosity of a recognizable variable is known and this kind of variable star can be found in a distant stellar system, the distance of the latter can be estimated from a measurement of apparent and absolute magnitudes, provided the interstellar absorption is also known.
