For celebs, it's location, location, location

After a huge amount of research, which included combing through an entire year's worth of Getty Images, an American professor, Elizabeth Currid-Halkett, claims to have discovered what makes someone a top-flight celebrity.

And, as it turns out, winning an Oscar is not a guarantee of that status. After conducting her research at the University of Southern Carolina, Currid-Halkett has published a book Starstruck, in which she analyses what it takes to be a modern celebrity.

If you've ever wondered how the likes of the hotel heiress Paris Hilton and the singer-turned-TV-presenter Cheryl Cole are as well known as they are, here's your answer.

First up, location. Over 80 per cent of the images examined were found to have been taken in only three major cities - London, LA and New York - and indeed, in just a few areas of those cities, although celebrity satellite locales such as Sundance, the mountain resort in Utah, were also important.

Second in importance, having the right social network, although this one is a little harder to join than Facebook.

It seems that the same 20 members of the celebrity elite - including George Clooney, Angelina Jolie and Tom Cruise - tend to frequent the same events together. Not exactly an easy group to blag your way into, and it gets worse.

According to Currid-Halkett, in terms of location, influence and connectedness, the famously intimidating Vogue editor Anna Wintour is the "ultimate gatekeeper" of celebrity. In the age of reality television and instant fame, it probably needs such a firm hand, one feels.