Brief introduction of southern cross constellation

The part of the Milky Way where the Southern Cross is located is the brightest part of the Milky Way. Its center position: right ascension 12: 20, declination -60 degrees. Although the Southern Cross is small, there are many bright stars. Alpha star is a famous bright star in the southern sky and a binary star. The beta star is 1, and there are 7 stars brighter than 4. The main bright stars in the seat, cross I (γ), cross II (α), cross III (β) and cross IV (δ) form a cross. Draw down from the vertical bottom of the cross until the point about four times the vertical length is the south celestial pole. Observed at low latitudes in the northern hemisphere, the intersection of this extension line and the horizon is basically due south. Because there are no bright stars near the south celestial pole, cross I and cross II are used to indicate the direction-only by extending the distance between them by about 4.5 times is the south celestial pole. This cross is no less important in the southern hemisphere than Beidou in the northern hemisphere.

In addition, the intersection of the middle vertical line connecting Nanmenxing Centauri and Marbury I and the above extension line will also be the south celestial pole. This constellation cannot be seen in most parts of the northern hemisphere, and only a few southern provinces can see it.

You can observe the latitude range of the whole constellation: 25 degrees north latitude to 90 degrees south latitude.

Observe history

/kloc-Zheng He, a navigator in the 0/4th century, used this constellation to navigate when he went to the Western Ocean. In Ptolemy's time in ancient Greece, it could be seen in the Mediterranean and was regarded as the foot of a centaur. Due to precession, in modern times, this part of the starry sky has moved south and can no longer be seen in most parts of the northern hemisphere.

It is generally believed that the French astronomer Augustin Royer first drew the Southern Cross as a constellation from Centauri in 1679. But before that, this constellation has been widely known.