Page 581 - 89 history of astronomy_opt

In 1835 Struve assigned a doubtful par-
˜
ˆ
allax of 0”.261 to Vega (I l LyrA). But Bessel’s
observations, between 1837 and 1840, of 61
Cygni, a star with the large proper motion
of over 5”, established its annual parallax
to be 0”.3483; and this was confirmed by
Peters, who found the value 0”.349.
ˆ
Later determinations for I lˆa Centauri,
by Gill,[2] make its parallax 0”.75–This is
581