Super Stars of Astronomy - The Biggest, Brightest, and Hottest of Them All

Super Stars of Astronomy - The Biggest, Brightest, and Hottest of Them All
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Brighter Then the Brightest Bulb

Looking up at the Sun, which you should never do, you’ll probably have a hard time imagining anything else being brighter or hotter, but in fact there are thousands upon thousands of larger, hotter, and brighter stars in the Universe that trump every aspect of our Sun.

Big

At a little over 100 times larger than the Earth, the Sun is no doubt a big star. But how big is it compared to the biggest stars in the Universe? Another relatively large star, which most people have heard of is Polaris, the North Star, which can be seen throughout the year in the Northern Hemisphere. At about 30 times larger than the Sun, Polaris is a significantly larger star, but that’s not even the start of it. Even larger than the Sun and Polaris combined, coming in at a whopping 1,800 times larger than the Sun, and holding the title of largest star in the known Universe, is VY Canis Majoris. This monster of a super star is so large that it was believed to have broken the laws of stellar evolution when it was first discovered. However, later observations brought it down to size, but it’s by no means small.

If VY Canis Majoris existed in our Solar System, the very edge of the star would extend out to the orbit of Saturn, over 841 million miles from the Sun. And yet, there exists an even more bizarre star in the Universe, one which is smaller than both VY Canis Majoris and Polaris, while still being the most massive star in the cosmos.

Enter, R136a1, as it’s known, a super star that tips the scales at over 230 times the mass of the Sun, or 1 x 1033 pounds, that’s a one followed by thirty-three zeros. R136a1 is so massive that it’s believed to be a part of a theorized group of super stars that, once they die, will not only go nova, but hypernova. This type of star explosion is believed to be at least 100 times more powerful than a regular supernova. If there’s one thing a super star can be related to in astronomy, it’s the likelihood that it will go supernova.

Supernovae are the biggest and most powerful explosions in the entire Universe, taking the power of nuclear fusion itself and harnessing it to create a destructive force capable of destroying planets and even creating black holes. And R136a1 is among a number of stars that takes that destructive force and multiplies it a hundredfold.

Bright and Hot

Anyone who’s taken a basic chemistry course or spent a good amount of time in the kitchen will know that the brighter and closer to the color white a flame is, the hotter it is. This holds true for stars as well. The brightest and bluest of the bunch are also the hottest and because, in the world of astronomy, mass equates to energy, according to Einstein’s famous equation E=mc2, the most massive stars should also be the hottest and the brightest. This holds true, as R136a1 is not only the most massive star in the known Universe, but it’s also the hottest at around 95,000 degrees Fahrenheit and the brightest with an absolute magnitude of -12.5 and a measurement of 8.7 million solar units.

The Sun and R136a1 compared to two other stars

For comparison, our Sun has a surface temperature of around 10,000 degrees Fahrenheit. Additionally, the Sun’s luminosity in absolute magnitude is 4.75, with the more negative number being more luminous, and in solar units it’s measured at 1.

Something interesting worth noting about the measurement of a star’s luminosity is its apparent magnitude, or how bright it would appear to observers on Earth. Take the example of Sirius, the brightest star in our night sky. Sirius has an apparent magnitude of -1.5, making it easily visible even in heavily light polluted regions, but its absolute magnitude is a measly 1.4 compared to the -7.2 of Antares, another bright star visible throughout the early months of the year. This distinction is important because it means that there are likely even brighter and hotter stars out there in the cosmos, too far away to be distinguished with the current telescopic technology scientists have available to them.

Live Fast and Die Hard

The most amazing thing about these super stars is their thrilling evolution. Because of their incredible mass and energy production, these stars are destined to die young and in a catastrophic manner. As was previously mentioned, a star that would fall into the super star category will not burn up and fade away like our Sun, but rather put on a particularly monstrous fireworks show in the form of a supernova.

Betelgeuse, visible in the upper-left of the constellation Orion the Hunter

While these events are quick to occur in the astronomy world, they’re not so frequent in our lives, with supernovae visible to the naked eye being extremely rare. However, when they do show up, they do so in spectacular fashion. Take the supernova of 1054 AD, which was recorded by Arab and Chinese astronomers as being visible even during the daytime. The remnants of this stellar explosion can be viewed in the night sky as the beautiful Crab Nebula.

Though they are rare, a number of candidates for supernova explosions are ready to go at any moment. One of the most likely and one which would result in an explosion visible during the daytime is the star Betelgeuse, which constitutes the shoulder of the constellation Orion the Hunter. Whether Betelgeuse will go supernova tomorrow or a million years from now is impossible to know, but one thing is for certain, super stars like it are everywhere in this Universe just waiting to be seen displaying their mind boggling characteristics.

Sources

Information

VY Canis Majoris - UK Herschel Community

Sun - NASA

R136a1 - Sky and Telescope

Sirius - University of Illinois

Betelgeuse - Bad Astronomy

Images

Sun and VY Canis Majoris (Supplied by Mysid at Wikimedia Commons; Public Domain; https://en.wikipedia.org/wiki/File:Sun_and_VY_Canis_Majoris.svg)

Sizes of Stars Comparison by ESO/M. Kornmesser (Creative Commons Attribution 3.0 Unported License)

Orion the Hunter - Provided by Author