Brian May (left) handed over his thesis to Professor Paul Nandra

May recently carried out observational work in Tenerife, where he studied the formation of "zodiacal dust clouds".

The subject forms the basis of a 48,000-word thesis for Imperial College, London, where 60-year-old May studied before becoming a rock star.

"It's been the longest gap year ever," May said. "It was a tough decision back then to leave my studies for music."

But the star said that at the time, his "passion for music was stronger".

"I'm so proud to be here today," he told BBC London. "Astronomy has always interested me. I used to love sitting at home and watching Sir Patrick Moore on the Sky at Night."

If I fail I will fail big time - it will be a very public failure with all this press

Brian May

The guitarist is scheduled to discuss his thesis with the examining board on 23 August, his spokesman said. The results should be known some time shortly after that date.

"If I fail I will fail big time," May said. "It will be a very public failure with all this press."

The rock star is also preparing a concert to mark the inauguration of a telescope at the Observatory of the Roque de Los Muchachos in La Palma in the Canary Islands, where he completed his studies last month.

May recently co-authored a book with Sir Patrick Moore

"Nevertheless, as a fan of Queen, I am glad that he left science temporarily," he added.

May made his first astronomical observations for his thesis at the Observatorio del Teide in Tenerife in 1971, before his rock career took off.

He recently published a book on astronomy with The Sky at Night presenter Sir Patrick Moore.