Legendary astronomer dies

George Alcock as he would like to be remembered

By BBC News Online science editor Dr David Whitehouse

The death has been announced of British astronomer George Alcock. He was 88.

[Alcock] was a truly inspirational figure, probably our finest observer ever - irreplaceable

Martin Mobberley, British Astronomical Association

The finder of five comets and five exploding stars, he has been described as the greatest visual astronomer who ever lived under cloudy UK skies.

His 10 discoveries surpassed the achievement of Caroline Herschel, who identified eight comets in the late-18th Century. In finding his space objects, Alcock memorised the positions and brightnesses of over 30,000 stars.

The self-effacing schoolteacher, who scanned the skies in his spare time, was regarded as a giant by astronomers, both amateur and professional, all over the world.

Inspirational astronomer

Professor Brian Marsden, from the International Astronomical Union (IAU), told BBC News Online that George Alcock had made "a unique contribution" to his science.

His last public appearance in 1999

Martin Mobberley of the British Astronomical Association said Alcock "was a truly inspirational figure, probably our finest observer ever - irreplaceable".

George Alcock was born in Peterborough in 1912 and his first encounter with astronomy was as an eight year old, when he saw the partial solar eclipse of 8 April, 1921.

At his first meeting of the British Astronomical Association, when he was 18, tributes were being paid to W F Denning, discoverer of five comets and an exploding star in the constellation of Cygnus.

Making a mark

After the meeting, Alcock was approached by the veteran 90-year-old meteor observer Grace Cook, who let the young man know that he would eventually take the place of Denning.

Alcock took up observing meteors from his home on the edge of undrained fenland.

But by the early 1950s, it became increasingly obvious to him that the value of his meteor observations was being eroded by the radar work being carried out at Jodrell Bank in Cheshire. So he looked around for another way to contribute to astronomy.

He later said: "What could I, a single observer, with not much money, do, that would make a difference." Over the following years, he was to make a considerable difference.

Two comets in a week

On 25 August, 1959, he spotted an intruder in the constellation of Corona Borealis. It was his first comet and the first one to be discovered from the UK since Denning's final comet discovery in 1894.

The comet he found in 1983 as seen from space

But what elevated him to the status of a legend was that only five days later, he discovered another comet in the morning sky in the constellation of Cancer. According to Martin Mobberley, "two British comets in a week was, and still is, a fairytale event".

Alcock's third comet was discovered in March 1963, his fourth in September 1965 and his fifth 18 years later. He also found five novae, or exploding stars, the first being Nova Delphini in 1967. It was the first British Nova to be discovered since 1934.

He found another a few months later and for a while in April 1968 both were visible in the dawn sky. He often stated that the sight of those two novae together was "the greatest thrill of my observing career".

Almost gave up

According to Brian Marsden, Director Emeritus of the IAU's Central Bureau for Astronomical Telegrams, Alcock once thought of giving up.

"Some 18 years ago, he was bemoaning to me about both the poor English skies and the fact that professional astronomers were talking about applying automated discovery methods," Professor Marsden said. "At that time, he had found four comets and four novae. I wrote back to him in April 1983 urging him not to give up.

"'I'm ready now for your next discovery', was how I ended the letter. Just three weeks later, he obliged me by finding his fifth comet."

In fact, Comet IRAS-Araki-Alcock holds the record for the closest approach of a comet to the Earth in the 19th and 20th Centuries.

It was the brightest comet he had discovered and the fact he had done it from indoors looking through a window with hand-held binoculars just added to the legendary status of the man.

Standing ovation

His final discovery, on 25 March, 1991, when he was 78 years old, was a remarkable one in many ways.

He had a strong feeling that he was going to be lucky that night - so strong in fact, that he was not at all surprised when he spotted the exploding star.

His last public appearance was just after the solar eclipse of August 1999. At a meeting of international comet observers, he was the only one to get a standing ovation.

George Alcock was once asked how he would like to be remembered. He replied: "As an observer."

A biography of George Alcock called Under an English Heaven has been published by Genesis Publications.