The sun is the source of energy for everything on earth, it illuminates the earth, so many civilizations in ancient times worshipped the sun very much, but sometimes the sun can become evil.
For example, in the myth of the "Houyi Shooting Sun", 10 suns were originally on duty in turn, and one sun hung up in the sky one day, but suddenly one day 10 suns were going to appear together, the earth was roasted, and the living beings were destroyed, so Houyi shot 9 of them, leaving only 1.
Now we know that there is only one sun in the solar system, and our world, the Earth, orbits the Sun, and that sunrises and sunsets are caused by the rotation of the Earth itself.
Therefore, it is never possible to have 10 real suns appearing at the same time over the Earth, unless it is an "false sun" that appears under the influence of an optical reflection or the like.
However, in the universe, there are not many star-only star systems like the Solar System, mostly two, and sometimes three or more (more than 60% of the Milky Way is a multi-star system).
Illustration: Proxima b simulated by the artist
For example, the nearest extrasolar planet, Proxima B (only 4.22 light-years old), is in such a multistellar system that its world has three stars.
So, how will the three "suns" over Proxima B behave?
Picture note: The location of the South Gate 2
The three suns of Proxima Centauri b
The third brightest star in the night sky is Southgate II (α Centauri), and although we look at it as a bright spot, it is actually a triad system of three stars.
Among them, we see two with the naked eye - South Gate II A and South Gate II B (or known as Centaurus α stars A and B), while the other is a faint red dwarf star , Centaurus α Star C can not be seen with the naked eye.
Illustration: South Gate II A and B
Although we can't see the red dwarf with the naked eye, this star is the closest star to us in the vast universe, so it has a very familiar name - Proxima Centauri.
Proxima B is a planet of Proxima Centauri that was only discovered in 2016, and through various simulations, it is known that the probability of the planet being rocky is more than 90%, and it is still in the habitable zone.
Note: South Gate II A and B, the distance from Proxima Centauri to the Sun
Of course, in this article, we will not say much about what kind of world Proxima B is, we will mainly introduce the relationship between its three stars!
South Gate II A is a slightly larger yellow dwarf (G-type main sequence star) than the Sun, with a mass of about 1.1 times that of the Sun, much brighter than the Sun, Andanmen II B is an orange dwarf star (K-type main sequence star), with a mass of almost 0.9 times that of the Sun, but it is relatively faint compared to the Sun, and as a red dwarf, proxima centauri is only 12.5% of the Sun's mass, very dim.
How do three stars work?
Whether the star system of South Gate II is two stars or three stars has been somewhat controversial until 2017, when accurate measurements were made against the radial velocity of neighbors, and it was finally determined that Proxima Centauri is bound by the gravitational pull of South Gate II AB.
The relationship between this triad system is controversial because Proxima Centauri is so far away from the other two stars.
Illustration: The south gate is two left, the horse's belly is one right, and the red circle Proxima Centauri is circled
South Gate II A and South Gate II B are like a binary star system, they move around a common center, and their orbit is an eccentric ellipse with a period of 79.91 Earth years.
The closest time between South Gate II A and B is 11.2 AU, which is about the distance from Saturn to the Sun, and this distance was most recently in August 1955; and the farthest distance is 35.6 AU, which is almost the distance from Pluto to the Sun, and the last time the two were furthest was in May 1995.
However, compared to the South Gate II AB (ab hereinafter referred to as AB), Proxima Centauri is a bit distant, and its distance to AB reaches 13,000 AU, which is equivalent to 5% of the distance from the Sun to AB.
Since Proxima Centauri is not very massive, it is more like a celestial body rotating around AB than interacting with each other as it does between ABs;
At the same time, due to its long distance, Proxima Centauri has a very long orbital period, and it takes almost 550,000 years to orbit AB.
Now that we know how these three stars work, you might also be wondering what these three stars would look like over Proxima B.
Illustration: Comparison of the size of the two third stars of the South Gate and the Sun
What do the three suns over Proxima B look like?
First, let's determine the size of the next three stars on Proxima B.
Because the distance between South Gate 2 A and B is too far, if you look at them on Proxima B, they are only equivalent to two bright stars, not like two suns, so in fact, there is only 1 sun that can be seen on Proxima B - that is Proxima Centauri;
Because Proxima Centauri is very close to Proxima Centauri — only about 0.0485 AU, much closer to the Sun than Mercury , even if Proxima Centauri is only 14% of the Sun ' radii , a "huge" Proxima Centauri can be seen on Proxima B – almost 10 times the size of the Sun seen on Earth.
Illustration: Changes in the Moon
But because Proxima Centauri's luminosity is only equivalent to 0.0017 solar luminosity, it can illuminate the earth over Proxima Centauri, but it is not too dazzling.
In addition, public data show that the apparent magnitudes of South Gate A and B (the brightness of the celestial body observed by the naked eye, the smaller the value is brighter) are 6.8 and -5.2, respectively, which means that they are 140 and 30 times brighter than the brightest Sirius in our night sky, and are about as bright as the moon on the fourth day of the earth, and it is estimated that they can also see the road at night.
Although not very large and not very bright, Proxima B does see that The South Gate A and B are two stars, not one, and they appear to be about 0.3 degrees apart in the sky — about half the diameter of the full moon seen on Earth.
Note: The world of Proxima b
Finally: How do three stars work over Proxima B?
From the motion relationship of the three stars, it is not difficult to see that Proxima B's role here is a bit like our moon, then Proxima Centauri is Earth, and the combination of South Gate TWO A and B is the Sun (although the two suns are small).
Relative to South gateS A and B, proxima B's rotation gives it a "day" and a "night" — two stars appear in the sky at the same time during the day, and cannot be seen at night, just as the moon looks at the sun with respect to the rotation of the sun.
However, since Proxima B is so close to Proxima Centauri, it is likely that it has been tidally locked in like the Moon, so it may always be day on one side and night on the other side relative to Proxima Centauri, just as we can only see one side of the Moon on Earth forever.
So, the world of Proxima B is more interesting!
If you're in the world of Proxima B, you'll experience the normal "star-out and star-fall" of two bright stars, and either eternal day or eternal night.