Goodricke, John

(b. Groningen, Netherlands, 17 September 1764; d. York, England, 20 April 1786)

astronomy.

Goodricke, the British astronomical prodigy of the late eighteenth century whose discoveries laid the foundations of an important branch of stellar astronomy, died at not quite twenty-two years of age. But into this lamentably brief life—and despite the handicap of deafness and dumbness—he managed to compress enough accomplishment to earn a permanent place in the history of science. He was descended from an old family of English country squires, who, raised to baronetcy by the end of the fifteenth century, were occasionally called upon to perform minor diplomatic services. Thus Henry Goodricke, John’s father, spent several years in consular service at Groningen, where in 1761 he married Levina Benjamina Sessler.

Scanty records reveal little of Goodricke’s early childhood, beyond a suggestion that he became deaf and dumb as a result of a severe illness in early infancy. At the age of eight he was sent from the Netherlands to Edinburgh, to be educated at a school for deaf-mutes which Thomas Braidwood was conducting. Absence of school records conceals the early development of young Goodricke; but his progress must have been satisfactory, for in 1778 he was able to enter Warrington Academy—then a well-known educational institution in the north of England—which made no special provision for handicapped pupils. There, we are told by extant records, “… having in part conquered his disadvantage by the assistance of Mr. Braidwood, he attained a surprising proficiency becoming a very tolerable classicist and an excellent mathematician” (Turner, Historical... Academy). For the latter he had undoubtedly to thank William Enfield, an outstanding teacher and a mathematician of some renown. It was almost certainly he who awakened Goodricke’s interest in astronomy and set him on his subsequent career.

Just when Goodricke left Warrington Academy we do not know; but certainly it was not later than 1781, for his Journal of Astronomical Observations contains a first entry dated 16 November of that year at York (to which his family had returned from Holland in 1776); it is to this source that we must turn for a description of Goodricke’s discoveries.

On 12 November 1782, a few days before the first anniversary of the start of his diary, Goodricke recorded:

This night I looked at β Persei, and was much amazed to find its brightness altered—it now appears to be of about 4th magnitude. I observed it diligently for about an hour—I hardly believed that it changed its brightness because I never heard of any star varying so quickly in its brightness. I thought it might perhaps be owing to an optical illusion, a defect in my eyes, or bad air: but the sequel will show that its change is true and that I was not mistaken….

Goodricke was not the first to notice the variability of β Persei (or Algol, as it is more commonly known); the Italian astronomer Geminiano Montanari had done so more than a century before (1670) in Bologna. Goodricke was, however, the first to establish that these light changes were periodic. He continued his observations until the end of the season when Algol could be seen above the horizon at York; and it was not until 12 May 1783 that Goodricke communicated (through the good offices of Rev. Anthony Shepherd, then Plumian professor of astronomy at Cambridge) the results of his observations, in the form of a letter read before the Royal Society on 15 May.

This communication, which promptly appeared in print, created considerable interest in astronomical circles, and the Society’s council awarded its youthful author one of the two Copley Medals for 1783. Goodricke did indeed deserve it, for not only did he discover the first known short-period variable star but also established a remarkably accurate estimate of its period. (Goodricke’s original value for Algol’s period was 2 days, 20 hours, 45 minutes—differing from its true period by only 4 minutes. A year later [1784] he revised this period to 2 days, 20 hours, 49 minutes, 9 seconds—a result on which all subsequent observations had little to improve.) At the end of his communication, we find the following sentence, which makes it truly prophetic: “If it were perhaps not too early to hazard even a conjecture on the cause of its variation, I should imagine it could hardly be accounted for otherwise than… by the interposition of a large body revolving around Algol…” (Philosophical Transactions of the Royal Society,73 [1783], 474).

Nature had denied much to Goodricke but certainly not the gift of a splendid imagination; seldom in the annals of science has the first conjecture of a discoverer been more accurate. Within the remaining short life vouchsafed to him Goodricke discovered, besides that of Algol, the variability of two other naked-eye stars, β Lyrae (1785) and δ Cephei (1786), both of which became prototypes of other classes of variable stars. Unfortunately, Goodricke’s bold suggestion that Algol (and β Lyrae) was an eclipsing variable, as they are now called, was made too early to gain speedy acceptance among contemporary astronomers. It was destined to remain a hypothesis until 1889, when the German astronomer Hermann Vogel discovered that Algol is also a spectroscopic binary, whose conjunctions coincide with the minima of light. This established beyond any doubt the binary nature of Algol and similar variables.

In the meantime, Goodricke’s short life was fast running out. The last observation recorded in his diary is dated 24 February 1786. In April of that year the Royal Society elected him to fellowship, but he died at York only two weeks later, “in the consequence of a cold from exposure to night air in astronomical observations.” The immediate cause of his death is unknown, for he died largely unnoticed. No stone over his tomb at Hunsingore (close to the former family seat of Ribston Hall, Yorkshire) commemorates his final resting place.

BIBLIOGRAPHY

Goodricke’s papers published in the Philosophical Transactions of the Royal Society are “A Series of Observations On, and A Discovery of, the Period of the Variation of the Light of the Bright Star in the Head of Medusa, Called Algol,” 73 , pt. 2 (1783), 474–482; “On the Periods of the Changes of Light in the Star Algol,” 74 (1784), 287–292; “Observations of a New Variable Star,” 75 (1785), 153–164; and “A Series of Observations on, and a Discovery of, the Period of the Variation of the Light of the Star Marked δ by Bayer, Near the Head of Cepheus,” 76 (1786), 48–61.

Biographical information may be found in W. Turner, Historical Account of Students Educated at the Warrington Academy (Warrington, 1814).

ZdenĚk Kopal