The daily morning journal and courier., 1907-06-29
qUADRUPLE STARS.
To the Naked Eye They Appear Like
 Single Points of Light

Single Points of Light. It is hard to believe that star which appears to the naked eye as a single point of light is a system of ce- lestial bodies moving in orbits so vast that hundreds of our years are requir- ed to traverse them. This, however is the status of more than one of what we called fixed stars" and probably of very many more than we know. One of the most interesting cases is that of the star" Castor long known to be double, consisting of two pairs of stars. The members of each pair move in small orbit with period of a few days, and the two pairs. as wholes, move in huge orbit with a period of over 300 years. Says writer in Par is Cosmos, in note on this curious and wonderful system;
 Tt has long been known that Cas- 1 tor, the fine star of the constellation | Gemini, is not single body, but a system formed of two component stars of the second and third magnitude which are easily seen separately through the telescope; these two stars describe an elongated ellipse about their common center of gravity, and complete their vast revolution in $50 of our terrestrial years.
 "The use of the spectroscopie method which enables us to ascertain and measure the velocity of objects in the direction of the line of vision has ex- tended our ideas of this stellar system. In 1896 Mir. Belopolsky of Pulkowa ob- servatory announced that the compon- ent of the third magnitude, the less brilliant of the two, was itself a double star. and that the revolution of the two members of this system required only three of our days.
 "On the other hand, . MT, Curtiss of the Lick observatory has examined in its turn the component of the sec- ond magnitude and has found that it also forms a system of two stars, with period of nine days. He adds that the orbit of this latter system has a considerable eccentricity, while that of the system studied by Belopolsky is nearly circular. Thus Castor is 8 quadruple star.
 TO ascertain the dimensions of the two secondary systems it was neces- cor,, +o IrY,ovx, 4ha ionI;,7a 4ioua of tboir planes to that of the principal orbit, This point is left in doubt by spectro- scopic methods, and, on the other hand while the movements of the principal system may be watched through the telescope, the same lenses are incapa- ble of separating the components of the secondary systems, which appear as luminous points. Nevertheless, if we admit that the planes of all the or bits of the quadruple system coincide, then we may calculate the dimensions of the secondary systems. The semi major axes are:
 1,0S5,S74 miles for the system of the second magnitude,
 891, 709 miles for the system of the tnlfd magnitude.
 These figures are only approximate they represent about the hundredth oart of the suns distance from the earth; in any case these orbits, 50 small when compared with the earth's are still small with relation to the principal system of Castor, which, making a revolution in $50 years, must have enormous orbital dimensions.
 "Mr, Curtiss goes further. He tells us that the component of the third magnitude, although the less brilliant, is of the greater importance, owing to it's mass, which Is six times as great as that of the component of the sec ond magnitude. This is not the first time that in systems of multiple stars the order of luminous magnitudes has not coincided with that of masses.
 If We knew exactly what the par allax was, and consequently the dis tanee from us of this curious world of Castor, it would be possible to give the absolute value of the masses. As. suming the parallax to be 0.05 degrees, Mir. Curtiss finds that the whole Cas- tor system, with it's four stars, has a mass of 12.7 times that of our sun. And this surprising world is, to our eyes, only a luminous point in the starry sky!'-Literary Digest,