University of  Sussex MEDIA RELEASE

The Information Office, University of Sussex, Falmer, Brighton, BN1 9RH.

24 September l998 For immediate release


An undergraduate has astonished the astronomy world by being credited with the co-discovery of a new planet. Kevin Apps, studying Physics with Astrophysics at the University of Sussex, is the first UK astronomer to be involved in the detection of a new planet. His discovery was made in collaboration with world famous ‘planet hunters’ Geoff Marcy and Paul Butler of the San Francisco Group.

The team - who have discovered nine of the twelve planets so far identified - deployed the huge Keck telescope in Hawaii to find their planet, which is about two hundred times more massive than the Earth.

Inspired last year by a visit to the Keck telescope itself, Kevin, who has been an astronomy enthusiast since he was seven, approached the team in the hope of becoming involved. Asking Marcy and Butler for their new target list of stars, he scrutinised all three hundred as potential planet-bearers and discovered that thirty of them were unworkable.

Plucking up the courage to tell Marcy and Butler their stars were unsuitable was "pretty intimidating", but his temerity paid off. The team were "really grateful that I’d dug out these bad stars which were never going to turn up planets". Offering to choose thirty more stars as a replacement for the SF Group paid off too: "It was a joke, but they said ‘Yeah, go for it’".

Kevin’s theory is that solar systems comparable to ours may be the most likely to harbour life, so he based his search around Sun-like stars. He chose thirty stars which were "dead ringers for the Sun" - having the same size, mass, temperature and luminosity - and sent them back to Marcy and Butler to be monitored on the Keck telescope.

To his amazement, one of his stars, which is around 154 light years away in the Cygnus constellation, has turned up a planet which is itself incredible. At twenty five times closer to its star than the Earth is to the Sun, it is much nearer to its parent star than any planet found before. A deep blue-violet colour, the planet has an orbital period of only 3.1 days, and a temperature of around fifteen hundred degrees.

For Kevin, the find is "like a fairy story". He was delighted to have his stars monitored on the Keck telescope at all: "It’s the world’s largest telescope and very few professionals get to use it - only a dozen or so groups in the world. So for an amateur like me to get his stars on it is amazing - I was over the moon". But to be credited as the co-discoverer of a unique planet was beyond all expectation - "Marcy and Butler have been working on this for ten years at least, they are world famous, and they’ve put in hours and hours of work. I’m just an undergraduate who’s done a couple of weeks work, dug out a few stars and gets credited with having helped to discover this planet".

Geoff Marcy is indeed impressed with Kevin’s work, commenting: "He shows a fierce interest in this research. It’s great to have him as a colleague". Kevin himself is modest about his discovery, but he knows that "What I did was crucial - they wouldn’t have found this planet unless I’d done what I did. They certainly have the best method in the world, but even with that you can’t find anything without the right star".

The findings of the SF Group, with Kevin accredited, have been accepted by the Publication of the Astronomical Society of the Pacific.

( Note: Planets are found by detecting a ‘wobble’ in a star’s motion - the wobble indicates a disturbance which is caused by the gravitational pull of a large mass; the planet. The size and duration of the wobble determines the mass of the planet as well as the length of time it takes to orbit the star).

For further information please contact Sally Hall, Information Office, University of Sussex, Tel. 01273 678888, Fax 01273 678335, email

File maintained by USIS - 24th September 1998