Double-stars Sentence Examples
It was used by him in his earliest observations of double stars (1779-1783); but, even in his hands, the measurements were comparatively crude, because of the difficulties he had to encounter from the want of a parallactic mounting.
In the case of close double stars he estimated the distance in terms of the disk of the components.
The position-angles of double stars are reckoned from north through east, the brighter star being taken as origin.
He remained at Dorpat, occupied with researches on double stars and geodesy till 1839, when he removed to superintend the construction of the new central observatory at Pulkowa near St Petersburg, afterwards becoming director.
In the meantime some confirmation of the law has been obtained from terrestrial experiments, and observations of double stars tend to indicate for it a wider if not universal range.Advertisement
Sir David Gill tested the equatorial coude on double stars at the Paris Observatory in 1884, and his last doubts as to the practical value of the instrument were dispelled.
But these cases form a very small proportion of the total number of double stars.
In many other double stars the two components have very nearly the same proper motion.
Several double stars were observed during the 17th century, Ursae Majoris being the first on record.
In 1784 Christian Mayer published a catalogue of all the double stars then known, which contained 89 pairs.Advertisement
Struve at Dorpat examined 120,000 stars, and found 3112 double stars whose distance apart did not exceed 32".
These systems appear as a connecting link between short-period variable stars on the one hand and telescopic double stars on the other.
The two components of double stars often exhibit complementary colours.
There is another method of determining stellar distances, which is applicable to a few double stars.
For double stars see Burnham's General Catalogue (1907), and Lewis, Memoirs of the R.A.S., vol.Advertisement
More recent and better adapted to study is Bauschinger's Bahnbestimmung der Himmelskorper (1 vol., Leipzig, 1906), which, alone of the three, treats orbits of satellites and double stars.