The visual shape and multipole moments of the sun

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5220518

Beardsley, B J

This thesis describes the 1983 solar investigation performed at the Santa Catalina Laboratory for Experimental relativity by Astrometry (SCLERA). Solar-diameter measurements, with the North Solar Pole defined as {theta} {equals} 0{degree} polar angle, have been made between the following polar coordinates: from {theta} {equals} 0{degree} polar angle, have been made between the following polar coordinates: from 0 = 0{degree} to {theta} = 180{degree} (the polar diameter), from 0 = 90{degree} to {theta} = {minus}90{degree} (the equatorial diameter), from {theta} {equals} {minus}45{degree} to {theta} {equals} 135{degree} and from {theta} {equals} 45{degree} to {theta} {equals} {minus} 135{degree}. Expressing the Sun's apparent shape in terms of a Legendre series, these diameters enabled calculation of the P{sub 2} (quadrupole) and P{sub 4} (hexadecapole) shape coefficients. The theoretical framework used to provide a relationship between the observed shape of the Sun and the multipole moments of the solar gravitational potential field was improved to include, in general, the effect of differential rotation in both latitude and radius. It shown that large changes in the apparent limb-darkening functions were occurring near the equatorial regions of the Sun during the time of the observations. Evidence for periodic shape distortions near the equator were found.

• Research Organization: Arizona Univ., Tucson, AZ (USA)
• OSTI ID: 5220518
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
657003 -- Theoretical & Mathematical Physics-- Relativity & Gravitation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COORDINATES
DIMENSIONS
FUNCTIONS
GRAVITATIONAL FIELDS
LEGENDRE POLYNOMIALS
MAIN SEQUENCE STARS
MOTION
POLYNOMIALS
ROTATION
SHAPE
STARS
SUN