The cornucopia constellation.

Astra, the alpha star of Virgo, is the brightest star in Virgo and the 16 brightest star in the whole sky. Its English name is Spica, which means "ears of wheat". Kakuchi is a pair of spectral binary stars with massive dark companion stars, and it is also a near binary star. The apparent magnitude is 0.98 and the absolute magnitude is -3.5. 260 light years away. The main star is Cepheus beta variable, and its spectral luminosity type is B 1IV. The brightness varies from 0.95 to 1.05, and the dimming period is 4.0 14504 days (0: 00+0: 2 1.8 seconds on the 4th). The spectral luminosity of the companion star is B3V type. This bright 1 star can be seen in the southeast sky on a spring night in the northern hemisphere. To find Kakuchi, just follow the curve connecting bucket handle, the Big Dipper in Ursa major, and the Great Horn of Capricorn.

Located at the southern latitude of the celestial sphere about 1 1 degree, and also near the ecliptic, there may be an eclipse along the moon and other planets, that is, planetary occultation.

As a bright star with an apparent magnitude of 1, it can be calculated that its actual brightness is 2 100 times that of the sun. In fact, Kakuchi is a binary system that is very close and surrounded by each other. The distance between two stars in the system is only 0. 12 astronomical unit, and the orbital period is only 4.0 145 days. The spectra of the two stars belong to high-temperature B-type (subtypes B 1 and B4), both are blue dwarfs with medium-intensity hydrogen spectra, and both are Cepheus β-type variables. Jiaokou is also the brightest rotating ellipsoid variable star in the whole day.

Arcturus is one of the first-class stars with the highest temperature. The high temperature makes it radiate high-intensity ultraviolet rays at the same time, making it actually brighter than its appearance.

Extend the bucket handle curve of the Big Dipper to the southeast, pass through arcturus, and then continue to meet the gladiators. Its distance from arcturus is approximately equal to the distance from arcturus to the end of the barrel handle. This curve from bucket handle of the Big Dipper to Jiaojing is called "Daquan Curve".

Kakuchi is 260 light years away from us, with a surface temperature of 20,000 degrees Celsius and a bluish-white light. In ancient China, Jiao Suyi was the first star on the first night of "Twenty-eight Hostels". It slowly leaves the earth among the stars at a speed of 1.6 kilometers per second.

It is a bispectrum binary star and luminosity binary star with an orbital period of 4.0 145 days, and it is a dense binary star with a large mass. It is about 84 parsec (about 275 light years) away from us. The total variation of Kakuchi's apparent magnitude is 0.09 (1968), and the main reason for the variation of light is the revolution of two aspherical sub-stars, that is, the change of ellipsoid binary stars. Secondary causes of darkening include the pulsation of α. The pulsation period of a star is 0. 1738 days, which belongs to Cepheus beta variable star, and the amplitude of brightness and apparent velocity caused by pulsation is unstable. The inclination of the orbit plane of the binary star is about 659, the semi-major axis of the orbit is 27 times the radius of the sun, the eccentricity is 0. 13, and the motion period of the near-star point is143 for 20 years.

Zeta virgo

Zeta virgo

China star name. It was called "Li" in ancient times. Virgo Zeta. Third-rate star

Virgo zeta star consists of a pair of white and yellow stars that move with a period of 172. The two stars are close to each other, and it is becoming more and more difficult to distinguish them. They will be closest in 2007, and then they will be far away from each other.