The shape and position of cowherd and Vega

There are four small stars around Vega, which are arranged in a diamond shape and are regarded as "looms". Because of its fast rotation speed, Altair is ellipsoid in shape, like a "big-bellied uncle". Altair is located in Eagle, also known as Hegu II. Vega is the brightest star in Lyra, located at the right vertex of the triangle.

There is a dark star on each side of the Altair, and the three stars are roughly in a straight line, which is vividly called the "shoulder pole star". The Altair in the middle is the brightest, and the stars on both sides are considered as a pair of children of Altair and Weaver Girl. The Altair is so bright that it is easy to recognize even in the city.

Vega is known as the "Queen of Summer Night". Vega is easy to see in the city on a clear night. If the observation conditions are good, such as places with less light pollution, you can also see four small stars with slightly darker brightness next to Vega, which are parallelogram or diamond.

Vega is the first star photographed by photography and recorded by spectrum after the sun, and it is also one of the first stars to estimate the distance by parallax measurement. It used to be the calibration baseline of photometric brightness scale and one of the stars used by UBV photometric system to define the average value.

Physical characteristics of Vega

Vega, whose spectral type is A0V, is a main sequence star with white and blue colors, and its inner core is undergoing nuclear fusion from hydrogen to helium. Because massive stars fuse faster than small ones, Vega only stayed in the main sequence star for about 65.438+billion years, only 654.38+0/654.38+05 of the sun.

Vega's current age is about 455 million years, more than half of her life in the main sequence star stage. After leaving the main sequence star stage, Vega will become an M-shaped red giant and lose most of its mass, and eventually become a white dwarf. The mass of Vega is 2. 135 0.074 m ⊙, and the actual luminosity is 37 times that of the sun. Vega may be a dwarf Cepheid variable with a photoperiod of about 0. 107 days.

Reference: Baidu Encyclopedia-Vega