The Nacreous Oughts

18 August 2011

HD 85512b, or Gliese 370, at 36 light years would fit on my previous list around #16 (54 Piscium). A K5 star in the constellation of Vela, with a mass of 0.69, its 3.6 Earth-mass planet orbits in 58.43 days (with an eccentricity of 0.11). The pdf (Kaltenegger et al) suggests it sits just on the inside edge of the habitable zone, & would be "potentially habitable" with a cloud cover of more than 50%.

Parallax ".08975 & visual apparent magnitude 7.66 give a luminosity of 0.093310622 (bolometric 0.154857087). If the semimajor axis of this super-earth (call it "Mordred") is 0.260400468, then the average temperature works out to be (with any reasonably terrestrial atmosphere) over 160 degrees Fahrenheit (e.g. 75 Celsius)*. With a "tidal effect factor" of 10 times Earth's, this world is just on the cusp between synchronous rotation & a very long day (perhaps hundreds or thousands of earth-days long)... Its diameter must be around 11,000 miles, & the gravity 1.8 Earth's. So, it could be either a "ribbon world" (like our conception of Zarmina--), or else habitable most at the poles.

We may imagine the dwarfish, Hulk-shaped humanoid denizens wresting their arduous existence under a huge red sun whose setting would be witnessed, at most, one dozen times in a long life.

*If the planet rotates this slowly, the temperature extremes that one location experiences would be considerable (e.g. plus or minus 100 degrees Celsius). --For water not to boil at 175 C, the surface pressure must be at least 8.7 atmospheres--not unlikely for a terrestrial planet of this mass.

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