3 articles for "Regiomontanus"

**Regiomontanus**[Astro*Index]

(1436-1476) German astrologer and astronomer. Born at Konigsberg, Franconia; died at Rome, Italy. Named Johann Muller, his pseudonym, Regiomontanus (King's Mountain), is derived from the Latinized name of his birthplace. He founded an observatory and printing press at Nurenberg, where he published an early *ephemeris*, which was used by Columbus, and observed the comet which later became known as *Halley's comet*. He studied Greek to read Ptolemy in the original (rather than just the Arabic), and translated the *Almagest*. He strongly opposed the view that the Earth rotated upon its axis. He prepared new planetary tables, making the tables of Alfonso X current. Using Gutenberg's press to reproduce his tables, Regiomontanus introduced Germany to the Arabic algebraic and trigonometric techniques. In his final years, he was summoned to Rome by Pope Sixtus IV to reform the calendar, but died there of the plague. He wrote and published many books on astrology, and is best known to modern astrologers as the inventor of the Regiomontanus method of House Division.

See also:

♦ Regiomontanus House System

**Regiomontanus House System**[Astro*Index]

A true *House System* (uses *House Circle*s which pass through the North and South points on the Horizon). Named after Regiomontanus (Johannes Muller), who devised the system 100 years after that of Campanus. The *MC* and *ASC* are, respectively, the cusps of the 10th and 1st houses. The arcs along the *Celestial Equator*, between the MC and ASC, and between ASC and *IC* are trisected, and House Circles passed through the trisection points; where these House Circles intersect the *Ecliptic* marks the cusps of the intermediate houses

Dn = 60° + n30°, for n=1,2,...,12 Vn = sin(Dn)*sin(LAT)*sin(obl) Xn = cos(ST+Dn)*cos(LAT)*cos(obl) - Vn Yn = sin(ST+Dn)*cos(LAT) Ln = atan2(Yn,Xn-Vn)/CDR E x a m p l e: Given that: obl = +23.45° LAT = +37.00° ST = 07:32:00 = 113.00° MC = 10: 111.2768° = CAN 21°16.6' 11: 12: ASC = 1: 198.8521° = LIB 18°51.1' 2: 3:

See also:

♦ House Cusp ♦ House Circle ♦ House System ♦ Celestial Equator ♦ Cusps ♦ Ecliptic ♦ Horizon ♦ Mc ♦ Asc ♦ Ic ♦ East Point

**Regiomontanus House System**[Prima]

One of several house systems.

The celestial equator173 is divided into twelve equal segments, beginning at the east point. The house cusps are formed by the intersections of the house semi-circles with the ecliptic. Since the equator is not perpendicular to the northpoint-southpoint axis of the horizon, the houses are not equal.

See also:

♦ House Cusp ♦ House Circle ♦ House System ♦ Celestial Equator ♦ Cusps ♦ Ecliptic ♦ Horizon ♦ Mc ♦ Asc ♦ Ic ♦ East Point

Astro*Index Copyright © 1997 Michael Erlewine

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