Astronomy and related astronomical terms +

1. The tiny apparent displacement of stars resulting from the motion of the earth through space.
2. Apparent displacement of a star from its true position, due to the combined effects of the speed of light and the speed of the earth in orbit around the sun (about 30 kilometers per second or 18.5 miles per second).

1. The magnitude a celestial object would appear to have if it were at a distance of ten parsecs (10 times 3.261633 light years or 32.62 parsecs).
2. A measure of the true brightness of a star as if all stars were the same distance (32.6 light-years) from the observer.

The absolute magnitude of an object measured through a special yellowish filter that approximates the visual range of the human eye.

A nebula seen in silhouette as it absorbs light from behind; also, called a dark nebula.

An accumulation of dust and gas into larger bodies.

As an energy source, such energy comes from the sun collected and stored using mechanical pumps or fans to circulate heat-laden fluids or air between solar collectors and a building.

1. The fraction of incident light that is reflected in all directions from an uneven surface; especially, the surface of the earth.
2. The fraction of the solar radiation that is reflected back into space.

1. A reference to rocks whose primary constituents have not been formed in their natural or original places.
2. Material that is formed or introduced from somewhere other than the place it is presently found.

A red super giant star in the constellation of Orion.

It is the tenth brightest star in the night sky, although its brightness varies. It is over 10,000 times as luminous as the sun, and lies 650 light-years from earth.

Light takes 60 minutes to travel across the giant star.

Angular distance; usually measured in degrees, above the horizon.

The figure-8 representing the equation of time and the variation of the sun's altitude in the sky during the course of a year.

A unit of wavelength or distance, equivalent to 1/10,000 micrometer or 1/10,000,000,000 meter.

The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.

A solar eclipse in which a ring (an annulus or the figure bounded by and containing the area between two concentric circles) of solar photosphere remains visible.

Material made of atomic particles having certain properties opposite to those of ordinary matter.

If combined, matter and antimatter would explode.