James Bradley (September 1692?-July 13, 1762)
James Bradley was the third Royal Astronomer.
His date of borth is uncertain, but there is a baptism document of October 3,
1792 (see e.g. Wikipedia); this gives evidence for his birth in September 1792.
School and college education provided him with the degrees of a Bachelor of
Arts and a Master of Arts, and proceeded to a short ecclesial career as a
vicar. Besides, he started astronomical observing with his uncle, James Pound,
a skilled astronomer; their joint observations included the opposition of Mars
in 1719, the transit of Mercury of October 29, 1723, and measurements of double
star Gamma Virginis. Bradley was elected a Fellow of the Royal Society in 1718,
resigned from his ecclesial duties in 1721, and was appointed as astronomer in
Oxford, to the Savilian Chair of Astronomy. In 1742, he succeeded
Edmond Halley as third Astronomer Royal, a post held
for the rest of his life.
He retired in 1761 and died on July 13, 1762.
His most fundamental discoveries were that of the aberration of light
(1725-1728) from observations of Gamma Draconis,
and the nutation of the Earth's axis (1728-1748).
Bradley discovered
M48 and observed
M41, both on February 16, 1727.
These observations, noted as "Nebulous Stars," were noted in his observation
notes, but not immediately published, and thus unnoticed.
Only over a century later, in 1832, Rigaud published a clollection of
Bradley's work Bradley and Rigaud (1832), which
still was not widely recognized.
Bradley's descriptions are printed in under
"Astronomical Observations, Miscellaneus Observations":
- [M41]
-
16. 10h.1/2 a nebulos: about 4deg to the south of Sirius contiguous to a
small star.
- [M48]
-
Another [nebulous star] near the middle of an isosceles triangle formed by
three stars, the brightest and northermost has two small ones contiguous,
being in a line with it, the equal and longest sides of the triangle are
about 5deg f[ollowing]. The stars lie almost in the midway between Procyon
and Cor Hydrae.
Links
References:
- James Bradley and Stephen Peter Rigaud, 1832.
Miscellaneous works and correspondence, of the Rev. James Bradley.
Oxford University Press, 1832.
CVIII+528 p + 5 pl.
[Bibcode: 1832mwjb.book.....B].
The observations of the "Nebulous Stars" M41 and M48 is printed in chapter
"Astronomical Observations," p. 361.
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