Trio Of Neptunes And Their Belt

The video was recorded on the occasion of the discovery of an unsual planetary Neptune-like system using the HARPS instrument on the ESO 3.6-m telescope. The first animation shows a planetary system surrounding a nearby star HD 69830. The HARPS measurement indeed reveal the presence of three planets with masses between 10 and 18 Earth masses. The planets mean distance are 0.08, 0.19, and 0.63 the mean distance between the Earth and the Sun. They orbit their parent star in 8.67, 31.6 and 197 days, respectively. From previous observations, it seems that there exists also an asteroid belt, whose location is unknown. It could either lie between the two outermost planets, or farther from its parent star than 0.8 the mean Earth-Sun distance. The second animation illustrates the system, seen from inside the asteroid belt, which is assumed here to lie between the two outermost planets. The third animation illustrates the method used to detect the planets. A planet in orbit around a star will manifest its presence by pulling the star in different directions, thereby changing by rather small amounts its measured velocity. Here, the observer is assumed to be sitting at the right of the image. Using highly accurate spectrographs, like HARPS on the 3.6-m ESO telescope, astronomers therefore measure with the velocity of a star to detect the signature of one or more planets. The amplitude of the shifts provide astronomers with information on the mass of the planets.

Category:

Science & Technology

Tags:

• extrasolar
• planet
• Neptune
• asteroid
• belt
• star
• light
• spectrometer

[KadoatieXD]

name of star?