What is the picture of Cassiopeia?

Casio poya

One of the polar constellations. Located in the south of Andromeda and the north of Andromeda, it is far opposite to Ursa major, and can be seen all year round, especially in autumn, because it is close to the north celestial pole.

Extending the autumn quadrangle to the north, the gamma star Pegasus and the alpha star Andromeda have a bright 2m star, which is the beta star Cassiopeia (Polaris can be seen farther north along this line). The five brightest stars in Cassiopeia, β, α, γ, δ and ε, form the shape of an English letter "M" or "W", which is the most prominent symbol of Cassiopeia.

The "W" in Cassiopeia is far from the Big Dipper opposite Polaris.

So when Cassiopeia rose to the zenith in autumn, Beidou was the lowest place in the sky, even in the south of China. Without Beidou, we can connect the midpoint of δ star with ε and γ star and extend northward to find Polaris.

1572165438+1October 1 1, that is, in the Ming Dynasty, a new star that could be seen in the daytime suddenly appeared in Cassiopeia. Three weeks after the star appeared, it began to dim slowly.

It was not until 17 months later that 1574 disappeared from people's field of vision (this sudden "bright star" was called "supernova explosion" in astronomy). But 380 years later, radio wave radiation was found in this position, which is a powerful radio source, called Cassiopeia B radio source, which is the residue after supernova explosion.