APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
HD 82943: Planet Swallower
Explanation: Stars like HD 82943 are main sequence G dwarf stars with temperatures and compositions similar to the Sun . Also like the Sun, HD 82943 is known to have at least two giant planets , but unlike gas giants in our solar system their orbits are not nearly circular and bring them closer to the parent star . Astronomers now point to strong observational evidence that HD 82943 used to have more planets ... but swallowed them in the past. Such a cosmic cataclysm is illustrated above in an artist's dramatic vision. As a result, planetary debris would contaminate the outer layers of HD 82943. Researchers using a high resolution spectrograph at the European Southern Observatory's Kueyen telescope believe they have seen a clear signature of this contamination by identifying the isotope Lithium-6 in this sun-like star's spectrum . Because the light element Lithium-6 is so readily destroyed in nuclear reactions during star formation, no significant Lithium-6 should now exist in HD 82943 . Startlingly, perhaps the most likely explanation for the presence of Lithium-6 today is that it is left over from planetary material which formed separately and was then absorbed by the parent star.
| Date | May 18, 2001 |
|---|---|
| Credit |
Credit G. Israelian and R. Rebolo ( IAC ), N. C. Santos and M. Mayor ( Geneva Obs. ), ESO Illustration Credit: Gabi Perez (IAC) |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



