A star diagonal, erecting lens or diagonal mirror is an angled mirror or prism used in telescopes that allows viewing from a direction that is perpendicular...

surrounding the observation methods used to develop and populate the diagonal star tables, and the criteria used to select decans (brightness, position...

Newtonian telescope The tertiary mirror used in a Nasmyth telescope A star diagonal right-angled telescope eyepiece mount An optical Edwardian parlour entertainment...

A star is a luminous spheroid of plasma held together by self-gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked...

known as a pentalpha, pentangle, or star pentagon) is a regular five-pointed star polygon, formed from the diagonal line segments of a convex (or simple...

points of the heraldic star and the star lies with one point on the diagonal L3 at point P3 where circle C1 intersects the diagonal L3. The flag is coloured...

lens. Star Diagonal: Used to change the angle of the light coming out of a telescope, for easier viewing. Herschel Wedge: Similar to a star diagonal with...

telescopes historically List of telescope types Reflecting telescope Star diagonal Heliometer "Telescope Calculations". Northern Stars. Retrieved 20 December...

reducing the overall length for a given primary focal length. A prismatic star diagonal for an astronomical telescope may consist of a single Porro prism (configured...

in 1965.: 3275  Prism (e.g. Porro or roof prism) Catadioptric system Star diagonal Lautemann, Kerstin; Leonhard, Martin; Stern, Regina; Heda, Jennifer...