According to the conclusions of a new scientific study, it would appear that a nearby star that could very well pass as the Sun's twin has as many as 9 extrasolar planets in orbit around it. Thus far, astronomers have discovered very few stars that have more planets around them than the Sun.
The object, called HD 10180, has a similar mass to the Sun, as well as almost the same temperature and brightness. Its chemical contents are also nearly identical to those of our own star. Apparently, it was a little bit more efficient at creating exoplanets than the Sun.
Details of the new investigation will appear in an upcoming issue of the esteemed scientific journal Astronomy and Astrophysics. The data used in this study were collected using the High Accuracy Radial Velocity Planet Searcher (HARPS) instrument.
HARPS is a high-precision camera mounted on the European Southern Observatory's (ESO) 3.6-meter telescope, at the La Silla Observatory, in Chile. The instrument had no trouble observing HD 10180, which is located just 130 light-years away.
The camera works by searching for signs of Doppler shifts, which are patterns of motion that the star displays as a planet moves around it. Regardless of how small the world is, it exerts a gravitational tug on its parent star, and certain sensitive astronomic tools can detect those changes.
The original analysis of the HD 10180 system revealed the existence of five Neptune-like planets, masses from 12 to 25 times that of Earth, and a Saturn-like planet, with a mass about 65 times that of our world. It takes these exoplanets between 5 and 2,000 days to orbit the star.
Data proposed to support a seventh world were found to be inconclusive. What the new analysis of HARPS data shows is that the seventh world is indeed real, as are two others, previously unknown, Astrobiology Magazine
The exoplanets are smaller than their siblings, tipping the scales at 1.3, 1.9, and 5.1 times the mass of Earth, respectively. They are located very close to HD 10180's surface, completing a full orbit around their parent star in just 1.2, 10, and 68 days, respectively.
This means that the one located farthest away from the star – whose year lasts for 68 days – still flies around HD 10180 faster than Mercury – the innermost planet in our solar system – does around the Sun (88 days).
Astronomers behind the new study say that the nearest planets to the star are found just 3 million kilometers (some 2 million miles) and 14 million km (8 million miles) away, respectively. This means that the super-Earths are hot enough that zinc would melt at their surface.
This implies that there is no chance of life enduring there. However, the fact remains that this star system is the most populated we've ever encountered. It even has more planets than our own, and definitely more than any other system we've analyzed around another star.