Come in if you know astronomy. What does this mean?

This is "celestial coordinates", which means the specific position of a celestial body in the sky.

Celestial coordinate system is a coordinate system that describes the position of objects in the sky in astronomy. The representation of right ascension and declination belongs to the celestial equatorial coordinate system, also called the second equatorial coordinate system.

The coordinate system takes the plane passing through the center of the celestial sphere and parallel to the equatorial plane of the earth as the equatorial plane of the celestial sphere, and the great circle formed by its intersection with the celestial sphere is called the equatorial plane of the celestial sphere. The equatorial plane is the basic plane of the equatorial coordinate system. The geometric pole of the celestial equator is called the celestial pole, and the celestial pole opposite to the north pole of the earth is the pole of the equatorial coordinate system. Any great circle passing through the celestial pole is called right ascension circle or time circle; A small circle parallel to the equator of the celestial sphere is called a declination circle. As the right ascension circle of a point on the celestial sphere, the length of the great arc measured along this right ascension circle from the celestial equator to this point is the latitude coordinate, which is called declination. When the declination is measured from 0 to 90, it is positive to the north of the equator and negative to the south. Right ascension refers to the arc segment on the celestial equator between the right ascension circle passing through vernal equinox and the right ascension circle passing through celestial bodies, which is expressed by α. Starting from vernal equinox, it is measured eastward from vernal equinox, and the measuring direction is opposite to the apparent motion direction of the celestial sphere on Sunday, from 0h to 24h. An hour of right ascension, like time, can be divided into 60 minutes, and each minute can be subdivided into 60 seconds. Minutes and seconds of right ascension are not equal to angular minutes and seconds, and the conversion between them is 1 minute = 15 minute, and 1 second of time = 15 minute.

Right ascension: 8 h, declination:+45, indicating that this position is located at 45 north of the celestial equator and 120 east of the vernal equinox. This position is in Tmall constellation, one of the northern stars, with an area of 545 square degrees, and there are no too bright stars. Between Ursa Major, Gemini and Auriga. Tmall belongs to the spring constellation.

Equatorial coordinate system