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New Large Rocky Planet Found

Posted by ryuzaki0 on from the does-it-have-a-face dept.

An anonymous reader writes "Discovery News is reporting the discovery of a super-sized rocky planet orbiting a red-dwarf. The star is located about 9000 ly from the sun. The planet consists of rock and ice and orbits at around the distance of asteroid belt. The planet could not grow to Jupiter size because the star is small and the system ran out of gas. The planet is about 13 earth masses and was discovered using the microlensing technique. Since most of the stars in the Milky Way are smaller than the sun, we should expect more of similar findings."

5 of 119 comments (clear)

  1. Re:ya and so.... by Anonymous Coward · · Score: 3, Insightful

    -1: Flamebait

    Come on, everyone knows science is incremental. 99% of progress is unremarkable in and of itself, but quite often the process involved allows greater leaps to occur. For instance, the microlensing they are using in these systems are a good advance in optics -- now what other uses can we think of? And that doesn't even count what we can't even predict.

    Your attitude is just demonstrative of what is wrong with people today, they cannot think past the immediate, and certainly don't understand how we got to where we are today (hint: it's not by only making major breakthroughs).

    Westblogs

  2. Wrong! Gravity dependent on mass and density by ZombieEngineer · · Score: 4, Insightful

    Go back to your high school physics, g is proportional to the mass and the inverse of the distance squared. Assuming a sphere, mass equals density x 4/3 x pi x R^3. Apply the inverse R^2 term and you end up with g proportional to density x R.

    The planet might be 13 times the mass but if the density is the same as Earth then g is only 2.35 times that of Earth (cube root of 13).

    ZombieEngineer

    1. Re:Wrong! Gravity dependent on mass and density by ZombieEngineer · · Score: 3, Insightful

      OK, so I missed a step in the second line. Assuming constant density then volume is proportional to mass. Therefore R is proportional to the cube root of volume, and therefore R is proportional to cube root of mass. Using the previous derivation that g is proportional to density x R, then g is proportional to density x (mass)^(1/3). Why is this important? This allows for a planet to have a fairly wide variation in mass but still have a "reasonable" gravity. Assuming +/- 20% window for gravity, this would translate to a -48% to +72% of planetary mass.

  3. Re:ya and so.... by SeaDour · · Score: 3, Insightful

    This story is anything but useless, as it expands our understanding of the range of stars that can support a habitable planet. Sure, this world is probably too far from the red dwarf to have life, but the finding proves that red dwarf star systems can have rocky worlds like ours, perhaps even close enough to the star.

    The previous poster was right -- SCIENCE IS INCREMENTAL. We can't shrug off discoveries like these simply because they don't "excite".

  4. Re:ya and so.... by kst · · Score: 3, Insightful

    You know this is why people are loosing interest in the space program! Useless findings after useless findings are boring people to death.

    They found a new planet, 13 times the mass of Earth, and you're bored?

    Sheesh!