A white dwarf can be 100,000,000 times denser than a blue
In the simplest case, a hot luminous star begins to expand as its core hydrogen is exhausted, and first becomes a blue subgiant then a blue giant, becoming both cooler and more luminous. Intermediate-mass stars will continue to expand and cool until they become red giants.
However, the most massive star observed to date is the blue supergiant R136a1, which contains at least 265 times as much matter as the sun.
Red Giants are much bigger than Blue Giants and can reach sizes of 100 million to 1 billion kilometers in diameter. This causes them to be cooler than the Blue Giants.
Red supergiants have low surface temperatures, below 4,100 K. This is very cool for a star and makes them shine with a red colour. The star Betelgeuse in the constellation of Orion is a red supergiant. Blue supergiants are much hotter.
Green and purple stars do exist. The color of stars depends on their temperatures, and they emit radiation throughout the visible spectrum.
What is the biggest star in the universe? The largest known star in the universe is UY Scuti. It has an estimated radius of 1.188 billion kilometers. If UY Scuti were the center of our solar system, its photosphere, or outer shell, would reach just past the orbit of Jupiter.
The hottest: WR 102
These stars not only burn incredibly hot and bright, but their stellar winds also blast much of their potential fuel into space. The hottest known star, WR 102, is one such Wolf-Rayet, sporting a surface temperature more than 35 times hotter than the Sun.
The largest known red supergiant is thought to be VY Canis Majoris, measuring about 1800 times the size of the Sun. Imagine if the Sun extended out to the orbit of Saturn. Let's take a look at where red supergiant stars come from.
Alnitak is actually the brightest example of a type O star in the entire night sky. It's a multiple star system, some 1,250 light years away, with the largest member being a blue supergiant some 33 times the mass of the Sun and with a luminosity of over 200,000 Suns.
Some scientists have nicknamed blue supergiants the "rock-and-roll" stars, for their tendency to live fast and die young. In exchange for their tremendous size and energy, blue supernovas have short lifespans. They only live around 10 million years, which sounds like a long time ...
You can tell the temperature of the star. Red stars are the coolest. Yellow stars are hotter than red stars. White stars are hotter than red and yellow.
In the simplest case, a hot luminous star begins to expand as its core hydrogen is exhausted, and first becomes a blue subgiant then a blue giant, becoming both cooler and more luminous. Intermediate-mass stars will continue to expand and cool until they become red giants.
There are seven main types of stars, and they are grouped by a system called spectral classification. This system organizes stars into groups by their temperature, color, and luminosity (brightness). These groups are the O, B, A, F, G, K, and M-class stars.
Ishizuka ( Gaku - Minna no Yama ) launched the Blue Giant manga in Big Comic in May 2013, and ended it in August 2016. The manga was nominated for the eighth Manga Taisho Awards in 2015, as well as the ninth awards in 2016.
Ultimate Fate of our Sun:
As such, when our Sun runs out of hydrogen fuel, it will expand to become a red giant, puff off its outer layers, and then settle down as a compact white dwarf star, then slowly cooling down for trillions of years.
A: Roughly 5 billion years from now, the Sun will exhaust the hydrogen fuel in its core and start burning helium, forcing its transition into a red giant star. During this shift, its atmosphere will expand out to somewhere around 1 astronomical unit — the current average Earth-Sun distance.
"Earth won't be habitable, and the only chance for survival would be for an advanced civilization to migrate to a new planetary home." The planets' orbits may also become unstable. As the red giant loses mass, the star's gravitational hold on its planets becomes much weaker, so their orbits will expand.
A stellar core is the extremely hot, dense region at the center of a star. For an ordinary main sequence star, the core region is the volume where the temperature and pressure conditions allow for energy production through thermonuclear fusion of hydrogen into helium.
O-type stars form only a tiny fraction of main-sequence stars and the vast majority of these are towards the lower end of the mass range. The most massive and hottest types O3 and O2 are extremely rare, were only defined in 1971 and 2002 respectively, and only a handful are known in total.
According to a new study, a star discovered 75 light-years away is no warmer than a freshly brewed cup of coffee. Dubbed CFBDSIR 1458 10b, the star is what's called a brown dwarf.
The hottest thing in the Universe (Supernova)
Supernovas are the hottest thing in the Universe as they reach a million degrees Celsius. These explosive events occur when a star between 8 and 40 times more massive than our Sun reaches the end of its stellar lifecycle and explodes when its core collapses.
Our Milky Way galaxy — our cosmic home in the Universe — spans over 100,000 light-years in diameter and contains approximately 400 billion stars. There are about 60 galaxies, total, in our Local Group, and one of them, Andromeda, contains even more stars than we do.
The biggest single entity that scientists have identified in the universe is a supercluster of galaxies called the Hercules-Corona Borealis Great Wall. It's so wide that light takes about 10 billion years to move across the entire structure. For perspective, the universe is only 13.8 billion years old.
The largest planet in the universe is called ROXs 42Bb, and it's believed to have a radius up to 2.5 times that of Jupiter or slightly more. This is a massive planet believed to be in the Rho Ophiuchi cloud complex, and it was first discovered in 2013. This type of planet is known as a Hot Jupiter.