Prior to NASA's Wide Field Infrared Sky Survey (WISE), the third-goldenest star system from Earth was thought to be Woolf 359, 7.7 light-years away. Pen ~ fun ~ pavilion www.biquge.info

But in 2013, when a pair of brown dwarfs capable of emitting only infrared rays were captured by the Wide Area Infrared Sky Survey Explorer, the pair of brown dwarfs separated by each other by only about 0.1 light-years apart replaced Woolf 359 as the third-closest star system to Earth. And this star system is also named after the wise who discovered them.

This binary star system is a very rare brown dwarf binary star system.

A brown dwarf is a gaseous object that is similar to a star but not massive enough to ignite a fusion reaction at its core. A celestial body with a mass between a star and a planet, or a mass between the smallest star and the largest planet.

Strictly speaking, brown dwarfs are not stars, but should be called "stellar-like objects", which also have the most apt nickname - "failed stars".

Unlike ordinary stars, brown dwarfs cannot maintain luminosity through hydrogen fusion like normal stars due to their lack of mass, and cannot become main-sequence stars. However, they exhibit convection both inside and on the surface, and different chemicals do not exist in layers on the inside. They do not belong to stars, nor to planets, but to celestial bodies in between. Either there is not enough mass, or there is not enough compound inside to ignite the hydrogen inside, so it can't emit light and can't become a star. That's why this object is called a "failed star".

The WISE-J1049 binary star system is one such group of two failed stars, located about 6.5 light-years from Earth.

Although it is a binary star system composed of brown dwarfs, in line with the principle that no matter how small a mosquito is, it is also meat, Tang Feng did not hesitate to laugh at this pair of twins.

After mastering this pair of binary star systems, Tang Feng came to another brown dwarf.

This brown dwarf was also discovered by WISE, hence the name WISE-J0855. It is the fourth-closest brown dwarf star to Earth, and it is only 7.2 light-years away from Earth.

The brown dwarf, along with the binary star system in front of it, was only discovered in 2013, and they also squeezed Woolf 359 from the third-closest galaxy to the fifth.

Compared to the WISE-J1049 binary star system, the conditions of this brown dwarf are more extreme.

Brown dwarfs are not able to light up nuclear fusion, so the surface temperature of brown dwarfs is usually relatively low. But the surface temperature of this WISE-J0855 star is ridiculously low. Because this brown dwarf, which is about five times larger than Jupiter, has a surface temperature of only minus 48 to minus 13 degrees Celsius. This temperature is incredible even on a brown dwarf.

Perhaps this WISE-J0855 star is not the hottest brown dwarf of the whole day, but WISE-J0855 is definitely the warmest of all the brown dwarfs found by humans. In contrast, the Wise-J1049 binary system, which is also a brown dwarf, is much warmer......

Such an extreme low temperature did not make Tang Feng feel any mercy, anyway, it is also a failed star, so come to my brother's arms and let my brother give you a little warmth!

After four days, Tang Feng left the lone brown dwarf. Harvesting three brown dwarfs in a row was obviously not enough to satisfy Tang Feng. Therefore, Tang Feng rushed directly to the next star system on this line non-stop.

Compared to the three brown dwarfs that have just been discovered, the next star system is too famous, because this star system is the famous Sirius.

As the brightest star of the night that cannot be observed on Earth except north of 73 degrees north latitude, Sirius is definitely no less famous than Polaris.

We all know that Orion is very easy to see in the night sky, and the three planets located in the waist of Orion are side by side in the shape of "one", which is extremely obvious throughout the day. And if you look southeast along the three stars of the hunter's belt, you can see an exceptionally bright star shining with blue-white light, which is the brightest star in the night sky, Sirius, with an apparent magnitude of minus 1.5.

The scientific name of Sirius is Alpha Canis Major, which is a binary star system made up of binary stars. The brightest Sirius should be called Sirius A, and its companion star is called Sirius B.

The brightest Sirius we see is actually Sirius A. It is a star 23 times brighter than the Sun, with a radius of 1.8 times that of the Sun and a surface temperature of 2 times that of the Sun, up to 10,000C. It is a standard main-sequence blue dwarf.

And the inconspicuous Sirius B is an out-and-out white dwarf. This white dwarf, which is slightly smaller than the Earth, has a mass slightly larger than the Sun, and is the largest white dwarf discovered so far.

This somewhat terrifying white dwarf star has a density of up to 10 tons per cubic centimeter, and all the matter on it is degenerate.

The Nautilus's hull material is made from the core material of this white dwarf.

It is a well-known fact that the larger the volume and mass of a star, the shorter its lifespan will be. This principle applies to Sirius, and it is also universal.

In fact, the age of the Sirius binary system is younger than the Ross 154 and Ross 248 that Tang Feng once controlled. The age of the Sirius binary system is only about 250 million years old.

A mere 250 million years is not even the age of tooth replacement for an ordinary star, but for a massive star, it has already made them enter the prime of life in advance.

In terms of the mass and volume of Sirius A, Sirius A has a lifespan of only 2 billion years. After this lifetime, the brightest star of the day will begin to collapse as it runs out of fuel, eventually forming a white dwarf like Sirius B.

In fact, before Sirius A, Sirius B was the dominant star of this binary star system.

About 250 million years ago, Sirius B was a blue dwarf larger than today's Sirius A, which had about 5 times the mass of the Sun and was a true giant. At that time, Sirius A was a small red dwarf, and as the younger brother, it had been faithfully accompanying Sirius B.

It's just that Sirius B, which is larger and more massive, has a shorter lifespan. After a violent burn of about 130 million years, Sirius B began to undergo the supergiant phase, during which Sirius B threw out about four times the mass of the Sun and eventually collapsed into a white dwarf star slightly smaller than the Earth but slightly more massive than the Sun.

Some of the material thrown out by Sirius B dissipated in space, but about half, that is, twice the mass of the Sun, was mercilessly devoured by the younger brother Sirius A, turning Sirius A from an inconspicuous red dwarf star into the brightest star of the night today.

It can be said that Sirius, the brightest star in the night now, actually drank the blood of its twin brother and ate the flesh of its twin brother, and became what it has now with endless scenery......

For this kind of disloyal and unfilial little brother, Tang Feng's approach is to collect it directly! (To be continued.) )