Celestial Observation

Cassegrain Reflector

Cassegrain Reflector

Cassegrain Reflector The Cassegrain reflector(telescope) was designed by French engineer Laurent Cassegrain to compensate for the shortcomings of the Newtonian telescope. Light reflected by the concave mirror is incident on the convex mirror. Focus is created only after reflection by...

Newtonian Reflector Simulation

Newtonian Reflector

Refracting telescope A telescope that uses only the refraction of a lens is called a refracting telescope. There are two types of refracting telescopes depending on the combination of lenses. The Galilean telescope is often referred to as a terrestrial...

Refracting telescope (Kepler type, Galileo type)

Refracting telescope (Keplerian, Galilean)

Refracting telescope A telescope that uses only the refraction of a lens is called a refracting telescope. There are two types of refracting telescopes depending on the combination of lenses. The Galilean telescope is often referred to as a terrestrial...

Geocentrism and Heliocentrism

Geocentrism vs. Heliocentrism

Geocentrism, The Geocentric theory The Geocentric theory is a cosmic perspective in which the Earth is at the center, and all the stars revolve around the Earth. From the 13th to the 17th century, it was a widely recognized worldview...

Diurnal Motion (WebGL)

Diurnal Motion (WebGL)

If you are asked to access your location, please allow it. Your personal data is not stored on the server. Diurnal Motion Fix the camera towards the Polaris at night. When you shoot for a few hours in that state,...

Keplers law

Kepler’s law

Kepler and Tycho Brahe There is an astronomer before talking about Kepler (Johannes Kepler 1571 ~ 1630). That’s Tycho Brahe. Tycho Brahe (1546-1601) is a famous Danish astronomer. With the development of astronomical equipment, he left a vast amount of...

Horizontal Coordinate System

Horizontal Coordinate System

Celestial coordinate system A celestial sphere is an abstract sphere centered on an observer. All objects in the sky can be conceived as projected upon the celestial sphere’s inner surface. Horizontal Coordinate System The horizontal Coordinate System is a celestial...

Equatorial Coordinate System

Equatorial Coordinate System

Celestial coordinate system A celestial sphere is an abstract sphere centered on an observer. All objects in the sky can be conceived as projected upon the celestial sphere’s inner surface. Equatorial system The equatorial coordinate system is the most basic...

Celestial Equator and the Ecliptic

Celestial Equator and the Ecliptic

The tilt relationship of the celestial sphere and ecliptic The celestial equator is the enlargement of the earth’s equator to the celestial sphere. Therefore, the celestial equator can be represented by a line fixed on the celestial sphere. The ecliptic...