The Astronomy Book

101

See also: Messier objects 87 ■ The Milky Way 88–89 ■
Examining nebulae 104–05

URANUS TO NEPTUNE

seen by the naked eye, but Herschel’s
telescopic surveys provided the first
detailed observations available to
astronomers. He compiled a list of
more than 1,000 stars, star clusters,
and nebulae within these galaxies.
Herschel also made careful
observations of the distributions
of stars within the Milky Way.

Due to the orientation of the

solar system within the Milky

Way, the brightest section of it,

which is now known to be the core

of the galaxy, is only visible low

on the horizon from the northern

hemisphere during the summer

when nights are short. From the

southern hemisphere, the brighter

core is visible higher in the sky

and during the darker months of

the year, allowing easier and more

detailed observations.

The end result of Herschel’s

labors, The General Catalog

of Nebulae and Clusters of Stars,

listed more than 5,000 objects

in total. These included all the

objects observed by John and his

father, and also many discovered

by others such as Charles Messier,

since it was intended to be a

complete catalog of the stars. ■

The stars are the

landmarks of the universe.

John Herschel

John Herschel

John Herschel left Cambridge

University in 1816, already

a renowned mathematician.

He worked with his father,

William, and continued his

work after William’s death

in 1822. Herschel became

one of the founders of the

Royal Astronomical Society

and served as president for

three separate terms. He

married in 1826 and fathered

12 children. Herschel had

numerous interests in addition

to astronomy. While in South

Africa, Herschel and his

wife produced a portfolio

of botanical illustrations.

He also made important

contributions to photography,

experimenting with color

reproduction, and published

papers on meteorology,

telescopy, and other subjects.

Key works

1831 A Preliminary

Discourse on the Study

of Natural Philosophy

1847 Results of Astronomical

Observations Made at the

Cape of Good Hope

1864 General Catalog of

Nebulae and Clusters of Stars

1874 General Catalog

of 10,300 Multiple and

Double Stars

Combining observations from

both hemispheres produces a survey

of the whole surface of the heavens.

From each hemisphere, part of the

celestial sphere is always hidden.

A survey taken from Britain misses everything

33° below the celestial equator.

Adding observations from South Africa

would make a complete survey.