Ellipticity
From LoveToKnow 1911
ELLIPTICITY, in astronomy, deviation from a circular or spherical form; applied to the elliptic orbits of heavenly bodies, or the spheroidal form of such bodies. (See also COMPRESSION.) ...
Ellipticity
A quantitative measure of the shape of a galaxy. A completely spherical galaxy has zero ellipticity. A galaxy shaped like a cigar has a very high ellipticity.
Elongation, Greatest ...
ellipticity
A measure of the amount an ellipse deviates from a perfect circle.
elongation ...
Ellipticity redirects here. For the mathematical topic of ellipticity, see elliptic operator.
The flattening, ellipticity, or oblateness of an oblate spheroid is the "squashing" of the spheroid's pole, towards its equator.
parallactic inequality A secondary effect in the solar perturbations in the moon's longitude due to the ellipticity of the earth's orbit.
The flattening of the earth is the ellipticity of the spheroid and equals the ellipticity of the ellipse forming a meridional section the spheroid.
There are three basic types: spiral (further subdivided into normal spirals and spirals with a "bar" at the centre, and yet further subdivided according to the "openness" of the spiral arms), elliptical (subdivided according to ellipticity) and ...
The ellipticals are subclassified by their degree of ellipticity as they appear to the observer. E0 types are completely spherical, and E7 types are very elliptical (i.e., elongated). E1 through E7 have increasing degrees of ellipticity.
For nonspherical systems, an ellipticity must be taken into account, so that the brightness profile is measured along nested ellipses of constant intensity.
They are denoted by the letter E, followed by an integer n representing their degree of ellipticity on the sky.
The level of ellipticity varies from EG's that are completly spherical to cigar shaped EG's. A spherical EG is called an E0, the more non-spherical the higher the number it gets. E7 is about as non spherical as you are likley to get.
Elliptical Galaxies
Hubble's elliptical galaxies were classed according to the ellipticity of the galaxy, and given a Hubble type:
E = 10 x (1 - b/a) ...
Bohr and Sommerfeld thought these represent orbits with different ellipticity, and therefore, different angular momenta. Presumably, this shifts the energies of the levels--though no one could calculate those shifts.
Adding an additional quadrupole from the ellipsoidal Universe will make the probability of the low observed quadrupole even smaller, unless there is a reason that the quadrupole from the ellipticity will be equal and nearly opposite to the ...
at a radius of around PSR 1829-10 in the constellation Scutum by an independent group, which was subsequently retracted when it was discovered that a signal with an orbital period of a half year had been introduced by not including the ellipticity of ...
 See also: Orbit, Earth, Rotation, Mass, Distance
  
|
RSS
