William Rutter Dawes

William Rutter Dawes ( born March 19, 1799 in London, † February 15, 1868 in Haddenham ) was an English astronomer and clergyman. He led by particular observations of the planets and measurements of double stars.

Life and work

Dawes father was a mathematics teacher interested in astronomy. Dawes's mother died very early. When his father took up the position of the Governor of Sierra Leone, Dawes was initially raised by his grandfather in Portsmouth. From 1807 on he lived (apart from a two -year hiatus, during which his father was staying in England) in the family of the Rev. Thomas Scott, one of his time known commentator on the Bible.

Since his father had provided for him the career of a clergyman, Dawes studied theology under Scott, but could not accept some doctrines of the Anglican Church. He therefore took up the study of medicine, and practiced after graduation as a doctor. During this time he married the elder by a few years Widow of Thomas Scott. 1826 after the death of his only sister, he settled in Liverpool. He turned back to religion and became a small Anglican community in Ormskirk.

Dawes had from childhood a very keen interest in astronomy. His first telescope was a refractor with only 4 cm aperture, with whom he performed in Liverpool through an open window observations. In Ormskirk, he set up his first observatory, which was equipped with a 9- cm refractor of the company Dolland. Due to his health Dawes gave his church from 1839, accepted an offer from George Bishop and worked for four years at the observatory at Regents Park.

Dawes was considered one of the best observer of his time and was nicknamed " Eagle Eye " ( actually Dawes was terribly nearsighted ). From 1831 to 1844 Dawes led by accurate measurements of the positions of double stars.

In 1842 he married for the second time - his first wife had died several years earlier in Ormskirk. The marriage with the wealthy widow of John Welsby, a lawyer in Ormskirk, brought a financial independence with them. 1844 the couple moved to Cranbrook in Kent. Here Dawes built his second observatory, which he with a very good 6 - fitting out of the company Merz refractor from Munich inches (15 cm).

Him a close friendship with the astronomer John Herschel (son of William Herschel ) who lived only a few miles from Cranbrook with his family. In addition, he was a friend of William Lassell. On the night of September 18, 1848, as Lassell the eighth moon of Saturn (later called Hyperion ) found Dawes was visiting the Observatory at Liverpool. Since Lassell the faint dots first discovered, he is regarded as the discoverer of the moon (along with the Americans William Cranch Bond and George Phillips Bond, the perceived him in the same night).

1850 Dawes moved his observatory after Wateringbury, near Maidstone. In 1851 he discovered a deep dark areas in the umbra of sunspots. In 1852 he developed a special eyepiece that allowed the risk of minimizing solar observation and detailed observations of the photosphere. In 1857 he moved to Hopefield in Haddenham near the River Thames.

When his wife died in 1860, Dawes fell into a deep depression and his health continued to deteriorate. For years he suffered from very severe headaches. Now, asthma, heart problems and increasing numbness presented one. His observations could Dawes continue only in a very restricted.

During the opposition of Mars in 1864 he made 27 detailed drawings of the planet. For these created Richard Anthony Proctor one of the first maps of Mars, which was published in 1869.

Dawes died in 1868 at a stroke and was buried in the cemetery of Haddenham.

Honors

Dawes was recorded in 1830 as a member of the Royal Astronomical Society, which honored him for his achievements in 1855 with the Gold Medal of the Royal Astronomical Society. In 1865 he was admitted as a member ( "Fellow" ) to the Royal Society.

In his memory, each an impact crater on the Moon and Mars was named. Even today, William Rutter Dawes name also connected to the so-called Dawes criterion, in which he set up an empirical formula which gives the smallest angular distance in which two stars are still perceived as individual objects.

Swell

• Entry in the archive of the Royal Society (English)