ε 1 and ε 2 are composed of two stars respectively, ε 1 is composed of two stars with brightness of 5.1 and 5.5 and distance of 2.3 ″, and ε 2 is composed of two stars with brightness of 4.6 and 5.0 and distance of 2.6 ″, which can be resolved with a telescope of higher power.
The two member stars farthest from the star system can be easily distinguished by binoculars, and can even be separated by naked eyes under good observation conditions. The star in the north is called ε, and the star in the south is called ε; They are about 162 light-years away from the earth, and the two stars circle each other. At high magnification, each member star can be further decomposed into a binary system; That is to say, the stellar system contains two binary star systems orbiting each other. Whether these member stars can be seen is the common standard to measure the resolution ability of the telescope, because the members of each binary system are so close: the member stars of the ε system were 2.35 arc seconds apart in 2006, and the distance between the member stars of the ε system was also about the same in that year. After the first high-precision measurement of their orbits in the 1980s Position angle It has only moved a few degrees. The apparent magnitudes of the member stars of ε are 4.7 and 6.2 respectively, with a distance of 2.6 °, and a roughly estimated circle period of 1200 years; In this case, the actual distance between the two stars is about 140 astronomical units. The apparent magnitude of the member star of ε is 5.1 and 5.5, respectively, with a distance of 2.3 °, and the circle period may be half of the former. The distance between the two binary systems is not less than 0.16 light years, and the period of each other's orbit may be hundreds of thousands of years. Observers on one of the binary systems can see the other two stars twinkling in the sky less than 1 ° apart, with brightness about one quarter of the full moon.
The fifth member of the star system, the companion star of a member star of the ε system, was Speckle photography Detected and confirmed by two subsequent observations. Due to the lack of observation data, its orbit cannot be determined, but its extremely fast moving speed shows that its circle period may only be decades. Because its maximum distance from the companion star is only 0.2 arcsec, it is impossible to see it optically.
