Richest Planetary System Discovered

[EarthlingX]

http://www.eso.org : Up to seven planets orbiting a Sun-like star

24 August 2010

Astronomers using ESO’s world-leading HARPS instrument have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180. The researchers also have tantalising evidence that two other planets may be present, one of which would have the lowest mass ever found. This would make the system similar to our Solar System in terms of the number of planets (seven as compared to the Solar System’s eight planets). Furthermore, the team also found evidence that the distances of the planets from their star follow a regular pattern, as also seen in our Solar System.

“We have found what is most likely the system with the most planets yet discovered,” says Christophe Lovis, lead author of the paper reporting the result. “This remarkable discovery also highlights the fact that we are now entering a new era in exoplanet research: the study of complex planetary systems and not just of individual planets. Studies of planetary motions in the new system reveal complex gravitational interactions between the planets and give us insights into the long-term evolution of the system.”

The team of astronomers used the HARPS spectrograph, attached to ESO’s 3.6-metre telescope at La Silla, Chile, for a six-year-long study of the Sun-like star HD 10180, located 127 light-years away in the southern constellation of Hydrus (the Male Water Snake). HARPS is an instrument with unrivalled measurement stability and great precision and is the world’s most successful exoplanet hunter.

The newly discovered system of planets around HD 10180 is unique in several respects. First of all, with at least five Neptune-like planets lying within a distance equivalent to the orbit of Mars, this system is more populated than our Solar System in its inner region, and has many more massive planets there [2]. Furthermore, the system probably has no Jupiter-like gas giant. In addition, all the planets seem to have almost circular orbits.

Research paper (pdf)

[youtube]http://www.youtube.com/watch?v=oBAnw03w71U[/youtube]

 

[csmyth3025]

Even though 127 light years away is "in our neighborhood", the chances that we'll ever be able to get there are pretty slim. Still, one wonders if one of these planets with masses between 13 and 25 Earth masses and orbiting at distances up to 1.4 AU around a sun-like star might have the right conditions to harbor life.

Maybe they're wondering the same thing about our solar system.

Chris

 

[alpha_centauri]

Not only are there 5 planets (and possibly 7) but maybe even eight! And that one could be even more intriguing.

From the paper on ESO's website,

http://www.eso.org/public/news/eso1035/ , http://www.eso.org/public/archives/rele ... so1035.pdf

From this analysis (Fig. 12), one can see that stable orbits are possible beyond 6 AU (outside the outermost planet’s orbit). More interestingly, stability appears to be also possible around 1 AU, which corresponds to orbital periods within 300 − 350 days, between the orbits of planets f and g, exactly at the habitable zone of HD10180. Among the already known planets, this is the only zone where additional planetary mass companions can survive. With the current HARPS precision of ∼1 ms−1, we estimate that any objectwith a minimummass M > 10 M⊕ would already be visible in the data. Since this does not seem to be the case, if we assume that a planet exists in this stable zone, it should be at most an Earth-sized object.

This system will probably be top of the list for improved spectrographs.

 

[JasonChapman]

This is really promising news, Its just a case of waiting for the boffins to say that they have discovered a multiplanet solar system and analysed the composition of one of the planets and it contains an atmosphere capable of supporting life.

 

[SpaceTas]

JasonChapman

Patience . It may take awhile. Need a space interferometer each telescope about size of James Web and positioning and optics technology we don't have.

But we "boffins" are already measuring the spectrum of a few gas giants and that is ahead of where people thought the technology would be.

 

[csmyth3025]

Given the relatively small sampling of stars that have been observed and the relatively large number of exoplanets that these observations have either detected or, at least, strongly suggested, it seems that planetary systems around stars are not especially rare.

I've read estimates that the number of stars in the Milky Way is somewhere between 100 billion and 400 billion. If we couple those numbers with the apparent prevalence of planetary systems, I suspect that there are more than a few Earth-like planets in our own galaxy.

The distances to even the nearest stars are prohibitively large. Barring the invention of the Warp Drive or the construction of a multigenerational spaceship "ark", I don't think we'll actually get to any other stars.

Nevertheless, it's interesting to speculate - and good fodder for science fiction writers - how the civilization(s) on another planet would feel about aliens (i.e., us) dropping in on them. Or, as has been depicted many times, how we would actually feel about them dropping in on us.

This is all just idle speculation so, please, don't consider this as an attempt to highjack this thread for every conspiracy theory crackpot in the forum to state their case for "big government" cover-ups.

Chris

 

[ZenGalacticore]

EarthX- Thanks for the vid and info.

Wow! Five Neptune mass planets within the equivalent orbit of Mars!

I wonder if one of those Neptune-mass planets is a giant, slushy waterworld? That would be too cool. About a year ago, I posted my expectation that such a type of planet would be found soon. One of these may be it. I don't believe that living worlds necessarily have to be in the ballpark vicinity of Earth's mass.

I don't know what life would be like on a giant, wet and relatively warm Neptune or Uranus, but it's not out of the question. Maybe it would have bones 14 times stronger than bone found on Earth. Or maybe some exotic kind of heavy exoskeleton.

Man, I wish we could travel across the light-years and see up close!

 

[EarthlingX]

EarthX- Thanks for the vid and info.

Wow! Five Neptune mass planets within the equivalent orbit of Mars!

I wonder if one of those Neptune-mass planets is a giant, slushy waterworld? That would be too cool. About a year ago, I posted my expectation that such a type of planet would be found soon. One of these may be it. I don't believe that living worlds necessarily have to be in the ballpark vicinity of Earth's mass.

I don't know what life would be like on a giant, wet and relatively warm Neptune or Uranus, but it's not out of the question. Maybe it would have bones 14 times stronger than bone found on Earth. Or maybe some exotic kind of heavy exoskeleton.

Just as a side note, let me remind you, that equatorial surface gravity on Saturn is 1.065 g, Neptune 1.14 g, Uranus 0.886 g. Not that bad.

Wiki :
Saturn

Neptune

Uranus

Saturn has currently 62 known moons, and i doubt this to be very special, since Jupiter has about that many too, and that is not counting asteroids in the Lagrangian points. I expect more satellites to be found around other local giants too, when we get some eyes a bit closer.

Ganymede, with 2634.1 ± 0.3 km is just a bit smaller than Mars (3,396.2 ± 0.1 km), and for a planetary hair bigger than Mercury (2,439.7 ± 1.0 km), but it might take a while before we are able to see such moons around exoplanets.

Man, I wish we could travel across the light-years and see up close!

I would be satisfied with a regular Earth-Moon-Mars-Venus-Ceres passenger line, for starters. I'm afraid we are going to be fed through the glass for quite some time more.

 

[EarthlingX]

news.discovery.com : Alien Planetary Systems Are Both Familiar and Surprising (video and other multimedia)

Analysis by Ray Villard

Mon Aug 30, 2010 02:28 AM ET

Over the past 15 years much planet-hunting has focused on simply cataloging individual worlds whirling about other stars. This search was turbo-boosted last week. Two teams of astronomers reported that they are at the point where they can study of the architecture of entire planetary systems.

By being able to characterize entire planetary systems -- from Jovian gas giants to Earth-sized planets -- we will gain important insights into the construction of alien solar systems in our galactic neighborhood.

I find the HD 10180 system more intriguing than Kepler-9 because it has five Neptune-mass planets huddle close to the star -- within the radius of Mars’ orbit. The outermost of these, HD 10180g, is within this star’s habitable zone where liquid water would remain stable. Though the planet is a 24 Earth-mass gas giant, it probably has a family of moons. Some may be big enough to be habitable by possessing an atmosphere and seas. This might be a great place to go looking for the blue-skinned "Avatar" aliens.

HD 10180 would be an intriguing system for a far future interstellar probe to reconnoiter. The artificial intelligent machine would be like the Saturn Cassini mission on steroids. The probe would tour all the moons and planets in HD 10180. It would obediently send back streams of spellbinding pictures to the descendants of its earthbound builders -- who would have to patiently wait 27 years for the first snapshot following the probe’s arrival. The probe might dispatch nanobot landers to do biology experiments on the surfaces of earth-like moons.

No doubt other bizarre and wondrous stellar systems await planet-hunters. It's a booming industry.

 

[bdewoody]

It seems now that the Drake equation relating to the number of planets in our galaxy that can support life needs some updating. As I recall one of the initial culling factors was the estimate of the number of stars that have planets and that number was very low. With all of the planets that have been determined to exist around various stars I think that percentage number needs to be raised by an order of magnitude.