The General Catalog of 1937

1. The General Catalog of 1937 Advances in positional astronomy

2. Nicolaus Copernicus devised the first comprehensive heliocentric model • Copernicus’s heliocentric (Sun-centered) theory simplified the general explanation of planetary motions • In a heliocentric system, the Earth is one of the planets orbiting the Sun • The sidereal period of a planet, its true orbital period, is measured with respect to the stars 1473-1543

3. Johannes Kepler proposed elliptical pathsfor the planets about the Sun Using data collected by Tycho Brahe from 1576 to 1597, Kepler deduced three laws of planetary motion: • the orbits are ellipses with the Sun at one focus; • a planet’s speed varies as it moves around its elliptical orbit; • the orbital period of a planet is related to the size of its orbit. 1571-1630

4. Galileo’s discoveries with a telescope stronglysupported a heliocentric model • The invention of the telescope led Galileo to new discoveries that supported a heliocentric model • These included his observations of the phases of Venus and of the motions of four moons around Jupiter 1564-1642

7. Barnard’s star has a parallax of 0.54 arcsec

9. Benjamin Boss (1880-1970) General Catalogue of 33342 stars (GC) (Boss 1937)

10. Astrographic Catalogs Zone Information Click here

11. HIPPARCOS Space Mission

12. HIPPARCOS Space Mission • Measured parallaxes for about 118,000 stars • Accuracy to about 0.001” for brighter ones • Accurate distances to about 100 pc • Distances and other data give valuable astrophysical information on most types of stars

13. Hyades Cluster

14. Hyades Cluster