Light deflection and time delay in the solar gravitational field

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6913850

Richter, G W

The second nonvanishing order of contribution to light deflection and time delay in the solar gravitational field is studied for a realistic solar model and for a wide range of metric theories of gravity. It is shown that the second-order effects arise at order (GM/c/sup 2/R)/sup 2/ identical to epsilon/sup 4/. To calculate these effects, every component of the solar metric must be known to order epsilon/sup 4/. The parametrized post-Newtonian (PPN) metric provides most of those components. However, some extension of the PPN metric is required. This extension leads to the parametrized post-linear (PPL) metric, which is used in all calculations. To study light deflection to order epsilon/sup 4/ requires that the orbits of scattered photons be known to that order. These orbits are solved for, first in the equatorial plane and then in general, and are used to determine the deflection as measured by an observer at rest with respect to the sun. In the equatorial plane there is only a radial component to this deflection. In general, there is another component orthogonal to the radial plane, but knowledge of this component is not necessary to determine the total deflection to order epsilon/sup 4/. The total second-order deflection can be as large as 300..mu.. arcsec (for deflection by Jupiter). Measurements of some second-order terms are within the astrometric capabilities of experiments proposed for the 1990's. The time delay in the round-trip travel time of a radar beam reflected from a planet is due to the variable coordinate speed of the light signal and to the bending of the beam path. The delay is calculated to order epsilon/sup 4/. It is shown that the beam-bending gives a second-order contribution as large as the present-day uncertainties in time delay experiments with the Viking spacecraft.

• Research Organization: Texas Univ., Austin (USA)
• OSTI ID: 6913850
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
GRAVITATIONAL FIELDS
MAIN SEQUENCE STARS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
METRICS
ORBITS
PHOTONS
POLARIZATION
RADAR
RADIATIONS
RANGE FINDERS
STAR MODELS
STARS
SUN
TIME MEASUREMENT
VISIBLE RADIATION