See also:EDWARD See also:CHARLES See also:PICKERING (1846- )
, See also:American physicist and astronomer, was See also:born in See also:Boston on the 19th of See also:July 1846
.
He graduated in 1865 at the See also:- LAWRENCE
- LAWRENCE (LAURENTIUS, LORENZO), ST
- LAWRENCE, AMOS (1786—1852)
- LAWRENCE, AMOS ADAMS (1814–1886)
- LAWRENCE, GEORGE ALFRED (1827–1876)
- LAWRENCE, JOHN LAIRD MAIR LAWRENCE, 1ST BARON (1811-1879)
- LAWRENCE, SIR HENRY MONTGOMERY (1806–1857)
- LAWRENCE, SIR THOMAS (1769–1830)
- LAWRENCE, STRINGER (1697–1775)
Lawrence Scientific School of Harvard, where for the next two years he was a teacher of See also:mathematics
.
Subsequently he became See also:professor of physics at the See also:Massachusetts See also:Institute of Technology, and in 1876 he was appointed professor of See also:astronomy and director of the Harvard See also:College See also:observatory
.
In 1877 he decided to
devote one of the telescopes of the observatory to stellar See also:photometry, and after an exhaustive trial of various forms of photo-meters, he devised the See also:meridian photometer (see PHOTOMETRY, STELLAR), which seemed to be See also:free from most of the See also:sources of See also:error
.
With the first See also:instrument of this See also:kind, having objectives of 1.5 See also:inch See also:aperture, he measured the brightness of 4260 stars, including all stars down to the 6th magnitude between the See also:North See also:Pole and -30° See also:declination
.
With the See also:object of reaching fainter stars, Professor See also:Pickering constructed another instrument of larger dimensions, and with this more than a million observations have been made
.
The first important See also:work undertaken with it was a revision of the magnitudes given in the See also:Bonn Durchmusterung
.
On the completion of this, Professor Pickering decided to undertake the survey of the See also:southern hemisphere
.
An expedition, under the direction of Prof
.
S
.
I
.
See also:Bailey, was accordingly despatched (1889), and the meridian photometer erected successively in three different positions on the slopes of the See also:Andes
.
The third of these was See also:Arequipa, at which a permanent See also:branch of the Harvard Observatory is now located
.
The .magnitudes of nearly 8000 southern stars were determined, including 1428 stars of the 6th magnitude and brighter
.
The instrument was then returned to See also:Cambridge (U.S.A.), where the survey extended so as to include all stars of magnitude 7.5 down to -40° declination, after which it was once more sent back to Arequipa
.
In 1886 the widow of See also:- HENRY
- HENRY (1129-1195)
- HENRY (c. 1108-1139)
- HENRY (c. 1174–1216)
- HENRY (Fr. Henri; Span. Enrique; Ger. Heinrich; Mid. H. Ger. Heinrich and Heimrich; O.H.G. Haimi- or Heimirih, i.e. " prince, or chief of the house," from O.H.G. heim, the Eng. home, and rih, Goth. reiks; compare Lat. rex " king "—" rich," therefore " mig
- HENRY, EDWARD LAMSON (1841– )
- HENRY, JAMES (1798-1876)
- HENRY, JOSEPH (1797-1878)
- HENRY, MATTHEW (1662-1714)
- HENRY, PATRICK (1736–1799)
- HENRY, PRINCE OF BATTENBERG (1858-1896)
- HENRY, ROBERT (1718-1790)
- HENRY, VICTOR (1850– )
- HENRY, WILLIAM (1795-1836)
Henry See also:Draper, one of the pioneers of stellar See also:spectroscopy, made a liberal See also:provision for carrying on spectroscopic investigations at Harvard College in memory of her See also:husband
.
With Professor Pickering's usual comprehensiveness, the inquiry was so arranged as to See also:cover the whole See also:sky; and with four telescopes—two at Cambridge for the See also:northern hemisphere, and two at Arequipa in See also:Peru for the southern—to which a See also:fine 24-in. photographic See also:telescope was afterwards added, no fewer than 75,000 photographs had been obtained up to the beginning of 1901
.
These investigations have yielded many important discoveries, not only of new stars, and of large See also:numbers of variable stars, but also of a wholly new class of See also:double stars whose binary See also:character is only revealed by peculiarities in their spectra
.
The important conclusion has been already derived that the See also:majority of the stars in the Milky Way belong to one See also:special type
.
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