Jul 30 2003
Following the triennial meeting of the International Astronomical Union last week in Sydney, astronomers found that so-called "heavy metal stars" were more likely to have planets associated with them.
Stars, like our Sun consist primarily of hydrogen and helium. They also contain metals such as iron, nickel and titanium. This can be determined by spectrographic analysis of the starlight.
After studying some 754 nearby stars, Dr. Fischer of the University of California found that stars containing these metals were more likely to bear planets, with 61 of them being associated with planets. Her findings indicated that:
- Stars containing roughly the same amount of metal as the Sun have a 1 in 10 chance of bearing planets
- Stars with approximately three times more metal than the Sun have a 1 in 5 chance of bearing planets
- However, the odds blow out to 1 in 33, if the star contains only a third as much metals as the Sun
These findings improve on old data which indicated that only 5% of stars have planets.
The reason for this is that stars and associated planets form from a common disc of gas. Since metals tend to stick together, it is easier to form solid matter such as dust and rocks and hence planets.
For more information on titanium, click here.