What seven stars does Beidou-7 specifically refer to?

There are seven bright stars in the northern sky arranged in a barrel shape. We often call them the Big Dipper.

The names of these seven bright stars are: Shu Tian, Tian Xuan, Tianji, Tian Quan, Yuheng, Kaiyang and Yaoguang. The first four stars are called "Dou Kui" or "Xuan Ji"; The last three stars are called "bucket" and "bucket handle". These seven stars are α, β, γ, δ, ε, ζ, η in Ursa major, and the other six stars are all second-class except the celestial force δ. The line connecting Tian Xuan β and Shu Tian α is about five times longer, and Polaris can be found. Therefore, beta and alpha stars are also called "Polaris".

Shu Tianxing: Ursa Major.

Western name: dubhe Bayer letter: Alpha Ursa major

Value: 2.00

Location (year J2000.0):

Right ascension:11h03m43.70s.

Declination:+6145' 03.2 "

Height: 54 12' 33 "

Azimuth: 048 49' 51"

U2000: Chart 24, Volume 1

Transfer: 04h 33m 1 1s

Tian Xuan

Constellation: Ursa Major

Western name: Melak

Bayer letter: beta Ursa major

Value: 2.40

Location (year J2000.0):

Right ascension:11h01m50.49s.

Declination:+56 22' 56.6 "

Height: 52 25 ft 3 1 inch

Azimuth: 057 19' 13 "

U2000: Chart 46, Volume 1

Transfer: 04h 3 1m 18s.

celestial pole

Constellation: Ursa Major

Western name: Phecda

Bayer letter: gamma Ursa major

Value: 2.50

Location (year J2000.0):

Right ascension:11h53m49.83s.

Declination:+53 41'41.1"

Height: 44 feet 38 inches 39 inches

Azimuth: 055 15' 46 "

U2000: Chart 47, Volume 1

Transit time: 05 hours, 23 minutes and 09 seconds

Tianquan

Constellation: Ursa Major

Western name: May Gorez

Bayer alphabet: Ursa Major Delta

Value: 3.40

Location (year J2000.0):

Right ascension:12h15m25.57s.

Declination: +57 0 1' 57.3 "

Height: 43 59 ft 16 in.

Azimuth: 048 59' 49 "

U2000: Chart 47, Volume 1

Transfer: 05h 44m 4 1s

Yu Heng

Constellation: Ursa Major

Western name: Aliot

Bayer letter: Ursa major ε

Location (year J2000.0):

Right ascension:12h54m01.76s.

Declination:+55 57' 35.6 "

Height: 39 feet 06 inches 28 inches

Azimuth: 045 49' 31"

U2000: Chart 48, Volume 1

Transfer: 06h 23m 1 1s

Kaiyang

Constellation: Ursa Major

Western name: Mizard

Bayer letter: zeta Ursae Majoris

Value: 2.40

Location (year J2000.0):

Right ascension:/kloc-0 13H23M55.55s

Declination:+54 55' 31.4 "

Height: 35 17' 26 "

Azimuth: 043 1 1' 00 "

U2000: Chart 48, Volume 1

Transit: 06h 53m 00s, which forms a famous visual binary star with auxiliary stars, and can be distinguished by naked eyes. This is a group of seven stars.

Alkaid

Constellation: Ursa Major

Western name: Alcaide

Bayer letter: eta Ursae Majoris

Magnitude: 1.90

Location (year J2000.0):

Right ascension:/kloc-0 13H47M32.44s

Declination: +49 18' 48. 1 "

Height: 28 feet 42 inches 54 inches

Azimuth: 044 29' 36 "

U2000: Chart 49, Volume 1

Transfer: 07h 16m 33s