We tend to think of celestial objects as round. Earth, Moon, Sun, planets and beyond – symmetrical orbs locked in gravitational waltz. Cosmic wobbles, wonky silhouettes, understandably obscured by the vastness of space.
All celestial bodies spin on their axis, rotation creates centrifugal force which pulls mass away from poles toward the equator. Our Sun has a radius at the equator 10 Km greater than its poles, Earth boasts a 21 Km variance. Be it sun, planet or moon, rotation flattens cosmic bodies into oblate spheres. Degrees of cosmic squashing depend on mass, composition and rate of spin.
A few weeks ago science declared Kepler 111451233 – roundest know object in the universe. Astronomer Laurent Gizon from Max Planck Institute For Solar System Research at University of Gottingen Germany, applied the science of asteroseismology to bestow symmetrical glory on a star 5,000 light years away. Asteroseismology measures the oscillation of stars to determine degrees of spherical flattening, all the while separating acoustic wave frequencies emanating from interior/exterior regions. Kepler 111451233 is twice the size of our Sun, spinning three times slower – not remarkable enough to justify round adulation. Cosmic tickles only erupt when factoring in acoustic wave anomalies indicating the exterior spins faster than the core. Science published an inexplicable holy crap – a distant star twice as big as our Sun, registering a measly 3 Km variance between poles and equator is the roundest known object in the universe.
So what you say? I say ponder the importance of edge pieces on a jigsaw puzzle. The roundest known object in the universe is an edge piece, without edges the puzzle falls apart.
KIC 11145123 and our Sun. Credit: Laurent Gizon et al/Mark A Garlick