oblateness


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oblateness

(ob -layt-niss, ob-layt -) (ellipticity; flattening) A parameter specifying the degree to which the form of a celestial object, such as a planet, differs from a true sphere, largely as a result of rotation. It is numerically equal to the difference between the equatorial and polar radii of the object divided by the equatorial radius. Saturn, with an oblateness of 0.108, is the most oblate planet in the Solar System.

oblateness

[ä′blāt·nəs]
(astronomy)
The distortion from a spherical shape in which the diameter at the equator exceeds that at the poles.
References in periodicals archive ?
At present, helioseismic measurements (see [section]6) indicate that the degree of solar oblateness may be slightly smaller [288, 289], but the general feature remains.
The absence of orbit-orbit resonances among the major moons in the Uranian system is thought to be related to the fact that the oblateness of Uranus is significantly less than that of Jupiter or Saturn.
Earth, which is less than 13,000 kilometers across the equator, has a much higher oblateness at about 27 kilometers.
Commentary relative to the seismic structure of the Sun: Internal rotation, oblateness, and solar shape.
Eclipse specialist David Herald conducted a full analysis that includes both oblateness and the best new information about the size of the umbra from a massive study of lunar eclipse crater timings he recently undertook with Roger Sinnott (S&T: June 2015, p.
The timings do show the umbra to be oblate, but only to the extent expected from the known oblateness of Earth and the geometry of the shadow cone.
therefore the phase difference detected by the Sagnac due to the contribution of the Earth's oblateness plus relativistic correction to the potential at perigee and apogee can be written as (24) or again (25).
Solar oblateness, [epsilon] is a dimensionless quantity
And as de Pater explains, "Uranus's oblateness, electromagnetic forces, and the pressure of sunlight act in concert so that the orbits of the tiniest particles probably get distorted the most, so that these particles, in contrast to the bigger ones, escape reimpacting Mab.
Solar oblateness [21] is a direct manifestation of solar rotation and can best be understood by examining the rotation of liquid masses [22].
Goldenberg at Princeton University, which indicated a slight but definite oblateness, with the equatorial diameter 0.
Many astronomers continued to favor a period around 24 hours, though it was widely acknowledged that such a short period was at odds with reliable micrometer measurements that failed to detect the appreciable oblateness expected if the planet spun so rapidly on its axis.