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Polar distance (PD) is an astronomical term associated with the celestial equatorial coordinate system Σ(α, δ) and it is an angular distance of a celestial object on its meridian measured from the celestial pole, similar as declination (dec, δ) is measured from the celestial equator:
PD = 90° ± δ .

Polar distance are expressed in degrees and cannot exceed 90° in magnitude. An object on the celestial equator has a PD of 90°.

Polar distance is not affected by the precession of the equinoxes.

If the polar distance of the Sun is equal to the observer's latitude, the shadow path of a gnomon's tip on a sundial will be a parabolaA parabola is a conic section generated by the intersection of a cone, and a plane tangent to the cone or parallel to some plane tangent to the cone. If the plane is itself tangent to the cone, one would obtain a degenerate parabola, a line. A parabola ca; at higher latitudes it will be an ellipseThe Ellipse is also an elliptical street immediately in front of the White House. In mathematics, an ellipse is a figure corresponding to a circle which has been stretched in one direction. This is an example of a conic section and can be defined as the l and lower, a hyperbolaFor hyperbole, the figure of speech, see hyperbole. In mathematics, a hyperbola is a type of conic section. Geometrically, it is defined as the intersection between a cone and a plane which cuts through both halves of the cone. Analytically, it is defined.


In geometryGeometry is the branch of mathematics dealing with spatial relationships. From experience, or possibly intuitively, people characterize space by certain fundamental qualities, which are termed axioms in geometry. Such axioms are insusceptible to proof, bu a polar distance, typically denoted r is a coordinate in polar coordinate systems (r, θ) and (r, θ, h).

The distance d between two points P1 and P2 with their polar coordinates (r1, θ1) and (r2, θ2) in two dimensional circular polar coordinate system is given by the polar distance formula:

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Polar distance is used also in botanyBotany is the scientific study of plants. As a branch of biology, it is also sometimes referred to as plant science(s or plant biology . Botany covers a wide range of scientific disciplines that study the growth, reproduction, metabolism, development, dis in classification of pollenSEM image of pollen grains from a variety of common plants: sunflower Helianthus annuus , morning glory Ipomea purpurea ,hollyhock Sildalcea malviflora , lily Lilium auratum , primrose Oenothera fruticosa , and castor bean Ricinus communis . Pollen is a fs.

Astronomy Physical quantityA physical quantity is the result of measurement and usually expressed as the product of a numerical value and a physical unit (whereby SI units are usually preferred). Example : P 42. 3 x 103 W 42. 3 kW where P represents the physical quantity for power



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