ellmm content Terellium is thought to possess abnormally high magnetic capacity under conditions of extreme density and high temperature a condition not obtainable as yet under laboratory conditions There is also a small, discrete region of very high field strength that is a result of the presence of the binary companion white hole Canopus B Canopus is a star of high stability with energy generator! varying less than 1 2 x 10 s over the period of a year Rarelv do star spots form in the photosphere those that do last at most a few davs The corona is not extensive but does ha\e slight periodic ARRAKIS ASTRONOMY 20 ARRAKIS ASTRONOMY variations These variations are manifested in a change in charged particle density in the stellar wind and m the stellar-wind velocity The gravitational field of Canopus is sufficiently strong to hold its retinue of six planets myriads of asteroidal fragments, and the dust and gas clouds situated near the outer periphery of the planetary system Because of the primary's high mass the veloci ty required to escape the gravitational hold of Canopus is 53 5 km/sec, thus the need for high energy propulsion systems for interstellar space vehicles PLANETARY SYSTEM Seban The innermost planet, Seban, has a mean radius of 2,380 km and orbits Canopus at a mean distance of 52 million km While Seban is massive enough to hold an atmosphere, the extreme physical proximity to Canopus and the intense coronal winds effectively drive any existing atmosphere tato space This coronal wind is so intense at times of closest approach to Canopus that a cloud of ionized metals and gases form and populate the trading orbital space This cloud is very tenuous and is composed chiefly of highly kinetic ions of iron, irerauffl, and melarmm The existence of this ionic cloud was not known until its discovery by the second Dren series plane tary probe during a survey of the Seban near space No life has been detected on Seban, conditions are far too harsh Menans Menans, the second planet inward, is much larger m radius (7,862 km) man Seban Menans orbits Canopus at a mean distance of 68 million km The orbit of Menans is highly elliptic and has an axial tilt of 79 Thus, Menans nearly rolls in its orbit with contrasting seasonal effects, one hemisphere eternally hot and the other eternally cold although the atmosphere mitigates the temperature effects to some extent Menans possesses a dense atmosphere of carbon dioxide with traces of nitrogen dioxide The latter component is responsible for the yellow brown tint Largely because of its oxidizing atmosphere, there are no known life forms on Menans Arrakis Menans, in combination with Extans (fourth planet m the Canopus system) is responsible for the highly eccentric orbit of the third planet, Arrakis Because of this joint effect and similarities of size and orbit, Menans and Extans are informally referred to as ' the Twins Fffects due to the other inner and outer planets as well as the two moons are negligible Because of the large axial tilt, the polar axis of rotation processes a full revolution every 43,000 years Currently, the star nearest the north celestial pole is the + 9 magnitude star Yuspen Arrakis has a density of 4 95 g/cm3 and an acceleration due to gravity of 864 cm/sec2 With a gravitational attraction of thib magni tude the light gases such as hydrogen and helium have all but escaped into space Atmosphenc pressure at the equator is 760 mm, about average for a planet of this diame ter and mass Arrakis is the only planet in the Canopus planetary system to harbor organic life forms Life on Arrakis has been subject to harsh conditions during its history Along with the local star group there is an extensive dust cloud that permeates the Canopus near space This dust cloud was first detected by the Arrakian astronomer Chelin m 12704 The consequences of the cloud were not fully recognized until 12984 when evidence was found that correlated ice age-like penods with the dust cloud opacity The peculiar velocity of Canopus carried it and the plane tary system through regions of varying cloud opacity This had the resulting effect of reduc ing the radiation incidents on Arrakis thus triggering near ice age conditions A similar but even more severe shift in conditions occurred when Arrakis s third moon was destroyed by an asteroid/comet some 200 000 years ago Krelln--first satellite Krelln is the larg est of the two Arrakian satellites Krelln has a mean radius of 488 km and orbits the parent planet at a mean distance of 324 077 km The satellite has a density of 3 97 g/cm3 and is composed of titanium rich silicates in the crust and mantel The silicate mantel extends to a depth of 170 km There is no apparent differentiation in composition which implies scant reheating following satellite formation The presence of a small rocky core has been established by seismic studies Large numbers of craters dot the surface ARRAKIS, ASTRONOMY ARRAKIS, ASTRONOMY of Kiel In.