BD+21 2934B, IDS 16260+2142 B, WDS 16302+2129B. ...
The angular direction of one body with respect to another; measured from north toward the east; typically used in the study of visual binaries.
The angle on the sky between two objects, such as the components of a double star. It is measured north - east and south - west, from 0 to 360º.
Angular distance (in degrees, measured from north through east) between the primary and secondary components of a binary system.
For a binary star, the position angle isthe angle (measured counterclockwise) at the brighter star between a linedrawn due north to a linedrawn to the fainter star.
~ (NASA SP-7, 1965) = parallactic angle. ~ (PA) (Comet Glossary - JPL) The PA of a tail or other cometary feature represents the direction on the sky (in degrees from north) toward which it is pointing. position vector (NASA SP-7, 1965) See vector.
Also called ~. parallactic inequality A secondary effect in the solar perturbations in the moon's longitude due to the ellipticity of the earth's orbit.
According to Roland Wielen (1962; see Brs 13 on page 603), who used a computer to mathematically iterate (photographic observations in both coordinates and visual observations of the ~) to "best fit" estimates, AB travel in an extremely eccentric orbit (e= 0.901) that takes 2, ...
The tail was 3 arcminutes long in ~ 70. The following evening I managed to see the comet in the twilight, ten minutes after sunset. V1 NEAT appeared like a small white patch lapping over the blue sky. After it had got dark I estimated its magnitude to be 4.
The separation never changes much from its current distance of only 0.2". Its 2000.0 ~ is 132º.
Much easier to resolve is component E, with a visual magnitude of 6.7, this is a binocular object at a ~ of 61º and separtion of 42".
A protractor shown is shown behind the black box and is free to rotate 360 degrees to measure the ~ of the double stars.
determine the position at a particular time we would also need the orbital period P and some sort of initial point, say the time T when the star was at "perihelion".) From the apparent orbit we can determine 5 parameters: the eccentricity and semimajor axis of the apparent orbit, the ~ ...
It is also the first to implement the "eyepiece view," with deep sky objects plotted to scale and galaxies rotated to show ~. This is an extremely detailed visual sky atlas program with too many features to mention here. Check out their site for more information.
In some, the ~s of the major axes of the isophotes are also a function of the isophotal level; that is, such galaxies possess an isophotal twist. Moreover, isophotes sometimes depart from pure ellipses in the sense of being slightly rectangular ("boxy").
in which emission features repeatedly appear off the core and follow fairly consistent nonradial paths.This can be seen in Fig. 1 of Zensus et al. (1995 ApJ 443, 35, courtesy of the AAS) in which a new component appears in late 1985, brightens, and moves outward changing its relative ~ ...
The space-VLBI observations ofJ0924-29 reveal a typical jet struture with milli-arcsecond accuracy, and the two jet components extend to the northeast direction with a ~ difference of 10°, which suggests a curved jet.
See also: What is the meaning of Sky, Astro, Earth, Star, Orbit?