Edmund Halley and The Moving Stars

Today, we remember Edmund Halley for Halley’s comet, which he wasn't the discoverer of, but he was the first to recognize at last that it was the same comet that graced our skies every 75 years or so. He lived an extraordinary life. He was not only an astronomer, but also a geophysicist, a mathematician, a physicist, and a meteorologist.

Edmund Halley's Early Life

Edmund was born in Haggerston, Shoreditch, London, England late in the year 1656. His father was a fairly well to do soap maker and property owner. He was educated at home for several years, before becoming a student at St Paul’s School.

He got married in 1682, and his father was murdered in 1684. Halley and his wife, Mary, had three children.

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Astronomy Facts:

The prime vertical is a great circle on the celestial sphere that passes through the zenith. It is a vertical circle that is bisected by the meridian. Degrees run from east to west.

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Edmund Halley's Training and Early Work

Edmund attended the St Paul’s School, excelling in astronomy and mathematics. He entered the Queens College at the age of 17, already a skilled astronomer. While an undergraduate he was already publishing his own papers on the solar system. Like many of his class, he left college without a degree.

He started working with the Astronomer Royal, John Flamsteed, and by 1676 he was making important discoveries of his own.

Edmund Halley's Astronomical Discoveries

When his mentor, Flamsteed, was off charting the stars of the northern sky, Halley went to do the same in the southern hemisphere. Halley was elected to the Royal Society in 1678, and he was given his degree by the mandate of Charles II in 1679. He spent a lot of time studying Kepler’s laws of planetary motion, and deduced that the planets moved in an ellipse.

Flamsteed for some reason became an enemy of Halley, and he prevented Halley from being appointed to a professorship at Oxford. But in 1704, Halley was appointed at Oxford as the Savilian Professor of Geometry, much to Flamsteed’s chagrin.

In 1710, Halley discovered the motion of several stars that were thought to be “fixed.” In 1712, he published Flamsteed’s star catalogs and observations. You can imagine what Flamsteed thought of that! Then in 1715, Halley published a summary of six variable stars known at that time, and in 1716, another about six known nebulae. Halley is responsible for discovering two deepsky objects: the globular clusters Omega Centauri (NGC 5139) and the Hercules Cluster (M13).

When Flamsteed died, Halley succeeded him as Astronomer Royal in 1720. Flamsteed’s wife was so livid at his appointment that she got rid of all her husband’s mathematical equipment so Edmund Halley could not use them.

Halley's Comet

In 1705, Halley published his Astronomiae Cometiae Synopsis, including the observation he made about the comet he had analyzed in 1682. He calculated the orbit, and thought it was similar enough to the comets observed in 1531 and 1607 to proclaim it was the same comet. He predicted its expected return in 1758, although he did not live to see it, dying in 1742. The comet was first seen again on Christmas Day, 1758, and reached its perihelion by mid-March, 1759.

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Astronomer of the day:

Arthur Eddington (1882-1945) was an English astronomer who first described the internal structure of a star.