Sir Patrick Moore, the veteran astronomer and TV presenter, died on Sunday aged 89, a group of his friends and staff said.
The broadcaster "passed away peacefully at 12.25pm this afternoon", at his home in Selsey, West Sussex, they said in a statement.
It added: "After a short spell in hospital last week, it was determined that no further treatment would benefit him, and it was his wish to spend his last days in his own home, Farthings, where he today passed on, in the company of close friends and carers and his cat Ptolemy."
Moore was born on 4 March 1923 in Middlesex and gained in interest in astronomy at an early age, running a small observatory at just 14.
Moore lied about his age in order to join the RAF in World War II and served as navigator in bomber command aged 16.
The only love of his life, his fiancee, Loma, was killed during the war when a bomb hit the ambulance she worked in as a nurse.
Speaking to the Evening Standard in 2007, Moore explained why he never married.
He said: "There was no one else for me. Second best is no good for me. I would have liked a wife and family, but it was not to be."
After the war he returned to astronomy and wrote his first book on the subject, Patrick Moore on the Moon, in 1952.
Moore presented the first episode of 'The Sky At Night' on 26 April 1957.
The monthly show went on to become the longest running TV show with the same presenter in history.
The last programme was broadcast on Monday.
Moore has only missed one episode since it began in 1957 when he was struck down by food poisoning.
His trademark monocle, unique delivery and occasional performances on the xylophone made him a familiar target for satirists and impressionists, but his scientific credentials were never in doubt.
The show's guests have included many prominent scientists as well as 'Goon Show' star Michael Bentine and astronauts Neil Armstrong and Buzz Aldrin.
But the demands of live television have led to the occasional blooper, with Sir Patrick famously once swallowing a fly live on air.
Moore became famous with a younger generation as the talking head in 'Gamesmaster', dishing out tips and cheats to eager viewers each week.
The show ran from 1992-98.
Moore had battled ill health in recent years, becoming wheelchair-bound and unable to look through a telescope.
Speaking to the Telegraph earlier this year, Moore said: "I can't operate my telescope anymore. My active life came to an abrupt full stop.
"I get up, drink my usual four coffees, have a look at the obituaries in The Times, and if I'm not in them, I'll get on with the day's work.
“I'm not scared of dying. I believe in some form of afterlife: I just hope my uncle George isn't there — silly, baldheaded old coot."
He died after failing to fight an infection.
The statement went on: "Over the past few years, Patrick, an inspiration to generations of astronomers, fought his way back from many serious spells of illness and continued to work and write at a great rate, but this time his body was too weak to overcome the infection which set in, a few weeks ago.
"He was able to perform on his world record-holding TV Programme 'The Sky at Night' right up until the most recent episode.
"His executors and close friends plan to fulfil his wishes for a quiet ceremony of interment, but a farewell event is planned for what would have been Patrick's 90th birthday in March 2013."
Queen guitarist Brian May paid tribute to a "dear friend and a kind of father figure to me".
He said: "Patrick will be mourned by the many to whom he was a caring uncle, and by all who loved the delightful wit and clarity of his writings, or enjoyed his fearlessly eccentric persona in public life.
"Patrick is irreplaceable. There will never be another Patrick Moore. But we were lucky enough to get one."
Moore, who had a pacemaker fitted in 2006, received his knighthood in 2001, won a Bafta for services to television and was a member of the Royal Society.
He wrote more than 60 books on astronomy and 'The Sky At Night' has inspired successive generations of stargazers.
Physicist and fellow television presenter Brian Cox wrote on Twitter: "Very sad news about Sir Patrick. Helped inspire my love of astronomy. I will miss him!"