Two stars in the
UY Scuti was discovered in 1860 by German astronomers; at the time, it was named "BD-12 5055." This star can be found near the center of the Milky Way, around 9,500 lightyears away from Earth. It is a part of the constellation Scutum.
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.
Answer and Explanation: The coolest stars in the universe are called red dwarf stars. These are relatively small stars that burn hydrogen at rates that are much more slow than hotter stars, so red dwarf stars will last much, much longer.
Vega is the fifth brightest star in the night sky, but that's not what makes it bizarre. Rotating 600,000 miles per hour, the intense speed bends it into an egg shape rather than spherical like our sun. It also has temperature variations, cooling at its equator.
These transparent, invisible stars give out no light whatsoever, meaning they skulk unseen in the celestial shadows. Astronomers already suspect that, unlike ordinary stars, most of the Universe is hidden from view.
These objects, known as brown dwarfs, have many of the elements of their more famous siblings but lack the mass needed to jumpstart nuclear fusion in their core. Because brown dwarfs never burn fusion at their core, scientists sometimes refer to them as "failed stars."
The highest stellar temperatures, however, are achieved by Wolf-Rayet stars. Destined for cataclysmic supernovae, Wolf-Rayet stars are fusing the heaviest elements. They're highly evolved, luminous, and surrounded by ejecta. The hottest one measures ~210,000 K; the hottest known star.
Finally, the award for the smallest known star in the universe goes to EBLM J0555-57Ab, according to a 2017 study published in the journal Astronomy and Astrophysics. The star is smaller than Saturn and barely qualifies as a star.
Red stars are the coolest. Yellow stars are hotter than red stars. White stars are hotter than red and yellow. Blue stars are the hottest stars of all.
Meet the Magnetar
The Magnetar is a widely accepted variation on a neutron star, and a common explanation for certain phenomena (like soft gamma repeaters and anomalous X-ray pulsars). The magnetar is, at the moment, the most powerful magnetic object known to exist.
Methuselah: The oldest star in the universe | Space.
A black star is created when matter compresses at a rate significantly less than the free fall velocity of a hypothetical particle falling to the center of its star, because quantum processes create vacuum polarization, which creates a form of degeneracy pressure, preventing spacetime (and the particles held within it) ...
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.
Milky Way Galaxy | AMNH. The Milky Way is the galaxy in which our Solar System lives. There are more than 200 billion stars in our spiral galaxy, and our Sun is just one of them. Even if you traveled at the speed of light, it would take you about 100,000 years to get across the Milky Way.
But even on average, if we were to consider all 200-400 billion stars in our galaxy, a mean distance of perhaps 40,000 light years away, there are perhaps only a few hundred thousand that are already dead — one in a million — and they're heavily skewed towards being on the far side of the galaxy from where we are.
The oldest star in the known universe is the Methuselah star, also known as HD 140283, a subgiant star. Methuselah is located in the constellation Libra, close to the Milky Way galaxy's Ophiuchus border, and around 190 light-years away from the Earth. It has a 7.205 apparent magnitude.
Micro black holes, also called mini black holes or quantum mechanical black holes, are hypothetical tiny (<1 M ☉) black holes, for which quantum mechanical effects play an important role.
If you were to compare planet Earth to the Sun, you'd find that you'd have to stack 109 Earths atop one another just to go from one end of the Sun to the other. Yet there are stars out there that are much smaller than the Earth… and much, much larger than even Earth's orbit around the Sun!
Blue stragglers are thought to form from the merging of two old, red stars, resulting in a star with greater mass and therefore bluer color – a theory developed with Hubble's help from imaging another globular cluster, 47 Tucanae.
In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II (bright giant).
The biggest star in the universe (that we know of), UY Scuti is a variable hypergiant with a radius around 1,700 times larger than the radius of the sun. To put that in perspective, the volume of almost 5 billion suns could fit inside a sphere the size of UY Scuti.
1) Supernovae are colossal explosions that occur when certain types of stars die. When a star, such as the Sun, dies, its outer layers are ejected into space, leaving its hot, dense core to cool over aeons. A supernova can have the same brightness as a galaxy of billions of "regular" stars.
When stars die, they become either black holes, neutron stars, or white dwarfs.
Pulsars are "fast transients," rapidly blinking on and off. Transients between these two extremes had remained elusive until now. Neutron stars including pulsars are among the universe's densest objects. They are roughly 7.5 miles (12 km) in diameter - akin to the size of a city - but with more mass than our sun.