In astronomy, astrology, and geodesy, the prime vertical or first vertical[1] is the vertical circle passing east and west through the zenith of a specific location, and intersecting the horizon in its east and west points.
In other words, the prime vertical is the vertical circle perpendicular to the meridian, and passes through the east and west points, zenith, and nadir of any place.[2]
A heavenly body is in or on the prime vertical when it bears true east or true west—when it is at right angles to the meridian. When a body is observed on the prime vertical for the purpose of calculating the longitude, a considerable error in the latitude by dead-reckoning (used in the computation) will not appreciably affect the result. By this it will be understood that the best time to observe a longitude sight (be it sun, moon, planet, or star) is when the body is on the prime vertical; but it is to be explained that it is not always possible to obtain such an observation, for a heavenly body can only be true east or true west when its declination is of the same name as the ship's latitude and less than the latter. When the declination of the body is of the same name but greater than the ship's latitude, the body's nearest approach will be some time after it has risen; but when the declination is of a contrary nature to the latitude, the body will be the nearest to the prime vertical at its rising and setting.[3]
^Barbieri, Cesare (2007). Fundamentals of Astronomy. New York: Taylor & Francis. p. 22. ISBN 978-0-7503-0886-1.
^"Prime Vertical · Astrological definition of Prime Vertical · Astrology Encyclopedia". astrologyweekly.com. Retrieved 2017-02-25.
^Patterson, Howard (1917). "Prime Vertical". The Navigator's Pocket-book. pp. 121–22.
In astronomy, astrology, and geodesy, the primevertical or first vertical is the vertical circle passing east and west through the zenith of a specific...
There are two principal radii of curvature: along the meridional and prime-vertical normal sections. In particular, the Earth's meridional radius of curvature...
marking the prime numbers. Ulam and Gardner emphasized the striking appearance in the spiral of prominent diagonal, horizontal, and vertical lines containing...
Vertex (band), formed in 1996 Vertex (astrology), the point where the primevertical intersects the ecliptic All pages with titles beginning with Vertex...
said to have devised a system of astrological houses that divides the primevertical into 'houses' of equal 30° arcs, though the system was used earlier...
axis) and the polar radius (semi-minor axis), respectively. N is the primevertical radius of curvature, function of latitude ϕ: N = a 2 a 2 cos 2 ϕ +...
said to have devised a system of astrological houses that divides the primevertical into 'houses' of equal 30° arcs, though the system was used earlier...
the primevertical. The vertical circle which is on the north–south direction is called the local celestial meridian (LCM), or principal vertical. Vertical...
^{-1}\left({\frac {N(1-f)^{2}+h}{N+h}}\tan \phi \right)} where N is the primevertical radius of curvature. The geodetic and geocentric latitudes are equal...
{\displaystyle f=1-{\frac {b}{a}}} is the flattening of the ellipsoid. The primevertical radius of curvature N ( ϕ ) {\displaystyle \,N(\phi )} is the distance...
oblique muscles. When the eye is abducted, the recti muscles are the primevertical movers. Elevation is due to the action of the superior rectus, and depression...
0° A prime meridian is an arbitrarily-chosen meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°....
Vx or 🜊 U+1F70A The vertex and anti-vertex are the points where the primevertical intersects the ecliptic. A crucible symbol, 🜊, is used by Astrolog...
ores. Vertical deflections were used to measure Earth's density in the Schiehallion experiment. Vertical deflection is the reason why modern prime meridian...
An electric vertical take-off and landing (eVTOL) aircraft is a variety of VTOL (vertical take-off and landing) aircraft that uses electric power to hover...
observe six stars). Morning Sun observation. Can be taken on or near primevertical for longitude, or at any time for a line of position. Determine compass...
Height is measure of vertical distance, either vertical extent (how "tall" something or someone is) or vertical position (how "high" a point is). For example...
bottom line. In the Arabic Ghubar writing, the bottom line was completely vertical, and the digit looked like a dotless closing question mark. Restoring the...
namely the horizon line (called the ascendant/descendant axis), and the primevertical line (called the zenith/midheaven and nadir/imum coeli axis), The angles...
largest known primes are Mersenne primes. The last seventeen record primes were Mersenne primes. The binary representation of any Mersenne prime is composed...
modern Western world to represent the number 1 is the Arabic numeral, a vertical line, often with a serif at the top and sometimes a short horizontal line...
Vertical transmission of symbionts is the transfer of a microbial symbiont from the parent directly to the offspring. Many metazoan species carry symbiotic...
MODIFIER LETTER PRIME. single apostrophe U+02BC ʼ MODIFIER LETTER APOSTROPHE. single vertical line U+02C8 ˈ MODIFIER LETTER VERTICAL LINE. Similar symbol...
literally "ghost leg diagram"). It consists of vertical lines with horizontal lines connecting two adjacent vertical lines scattered randomly along their length;...
In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form Mn = 2n − 1 for some...
ice field from east to west. At 06:52, after the sunrise, Moore took primevertical sight of the sun to determine his position and found out he was several...
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