Top 10 largest stars in the Universe
It was not until the 19th century that people finally accepted the fact that the Sun was not a stationary body and was, in fact, a star. No longer was it a deity or god and hydrogen was found out as its energy source. As technology advanced in leaps and bounds, it began to dawn on man that the solar system that was thought to be the whole of the universe was just the tip of the iceberg. Suddenly, the Sun was no longer a titan but a mere speck of dust in the universe as other stars many times its size were discovered like the VY Canis Majoris. Although it does contain 99.8% by mass of our solar system, it is nothing compared to the recently discovered stars. Paying homage to the star which was worshipped by our ancestors for millions of years, the diameter of the new found stars is roughly calculated with respect to the sun’s radius, hereto referred as solar radii. The diameter of the Sun is 1.392 x 109 meters (864,900 miles).Double stars are found in our universe and sometimes counted as one. Keeping in mind that values do fluctuate due to statistical variations, following is the list of top ten largest stars in the universe
10. Betelgeuse (Alpha Orionis)
At a distance of 640 light years from our planet; this supergiant is the closest one on the Top 10 largest stars of the universe list. Betelgeuse is also known as Alpha Orionis. This is due to the fact that this red colored star resides in the famous Orion constellation. This star has solar radii of 1,180.It is interesting to note that this star also appears on the list of top ten brightest stars at number 9. Betelgeuse is a dying star and will soon explode into supernova giving earth a second sun for around 2 weeks or more. No harm will come to us due to our distance, but the immense energy released will be visible as light in the most awesome fireworks show man has ever seen. This is expected to happen in the near future.
9. RW Cephei
Located in the Cepheus constellation of our Milky Way, RW Cephei is an orange supergiant and a very hot star with temperatures up to 4400K! These high temperatures can cause it to expand and hence create an uncertainty about its accurate size. However, scientists agree on solar radii of around 1260 to 1650 placing this star on 9th position in the largest stars in the universe list. Although a midget as compared to many of its neighbors, RW Cephei is almost as large as the orbit of the planet Jupiter. Temperatures keep varying and this is reflected by its pulsations in brightest and colors.
8. KW Sagitarii
1460 times the radius of our Sun, KW Sagitarii holds the 8th position in this list. This particular supergiant is also one of the brightest stars around with luminosity levels as much as 360,000 Suns! Being 10,000 light years away does make it less bright to the naked eye, but its size can be judged by the fact that it would cover almost half the area between Saturn and Jupiter! KW Sagitarii is located in the Sagittarius constellation of the Milky Way.
7. KY Cygni
The KY Cygni the center of debate due to its size. Some claim that this star is the largest one in the universe being 2850 solar radii. This claim has not been proven false. However, it is at least 1420 and placed 7th on the list till this uncertainty is cleared. KW Cygni is 5000 light years away from earth in a constellation know as Cygnus. Along with being one of the largest, it also is of the brightest stars as it is 300,000 times brighter than the Sun. This red super giant is about 25 times the mass of the Sun, or almost 50 nonillion kilograms!
6. V354 Cephei
V354 Cephei (marked V0345 on various charts) marks the beginning of a class called hyper giants. Slightly smaller than the WHO G64, it stands at the 6th position, having solar radii of 1520. It is located in the Cepheus constellation, which is supposed to represent a mythical king. It stands at 9,000 light years from our earth. It is so huge that it could easily cover the orbit path of Saturn if place where is the sun is! The red color of V354 Cephei indicates its temperature range to be around 3000 to 4000 K. Hotter stars tend to appear yellow and those which are extremely hot get a bluish tinge in their appearance.
5. WOH G64
At a distance of around 160,000 light years away, WHO G64 takes the 5th spot on the top 10 largest stars in the universe. Located in a nearby galaxy known as Large Magellanic Cloud, this hypergiant resides in the Dorado constellation. Its radius is 1540 times the radius of our Sun. Although this particular star has lost as much as half of its original weight due to ejection of material from its surface, it has formed a light year long thick ring torus of mass and dust around itself. These changes in mass had led astronomers to overestimate its density and were perplexed at its sustenance at such a low temperature. This was then fixed by accounting for all the mass present in its ring. This means that WHO G64 is unstable and already has lost as much as tenth of its mass. It is expected to go supernova in a couple of thousand years.
4. Mu Cephei
A hypergiant, known as Mu Cephei (µ Cephei) or Herschel’s Garnet Star, comes in at number 4 on our countdown list. It lies in the Cepheus constellation which is associated with the Garnet Star Nebula. Apart from being one of the brightest stars of our galaxy, it is also of the biggest; almost 1650 solar radii! Being 38,000 times brighter than the Sun, it is easily visible to the naked eye on the northern hemisphere on earth. Being garnet red in appearance has made it one of the most recognizable stars in our Milky Way. It is a confirmed variable with variations in brightness over a period of time. A comparative analysis of size would show that if earth was the size of a golf ball, then the diameter of Mu Cephei would be more than the length of two back to back Golden Gate Bridges!
3. V838 Monocerotis
This star could have easily been ranked second on our list if it hadn’t been for its baffling 20,000 light years distance from the Sun, making it hard to measure. However, almost all the astronomers agree on the 1570±400 solar radii range. It is named V838 Monocerotis or V838 Mon because it was the 838th variable star observed in the constellation of Monoceros. It was discovered during one of its three major blow ups starting in 2002. The star became as bright as one million Suns! Sudden expansion of layers and rapid cooling of gases during the explosion created one of the most breath-taking light echo ever witnessed by man. One theory about the explosions is that a planet almost three times the size of Jupiter was consumed by V838 Monocerotis releasing such a huge amount of energy. This theory is still a hot debate but it fits corresponds nicely to all statistics and figures.
2. VV Cephei A
Ranking second in our list is VV Cephei A from the 2,400 light years far Cepheus constellation and is second only to VY Canis Majoris. The VV Cephei is a double star system consisting of a red and blue supergiant. VV Cephei A (or VV Cephei α) is the red supergiant having solar radii of 1,600-1,900 and a luminosity factor equaling to 315,000 Suns. Matter is exchanged between the red star and the blue one. This is the likely cause of fluctuations in the stars brightness. The constant mass transfer continually changes dimensions of both the stars. Like the Betelgeuse, an accurate estimation is not possible for this star owing to its non-spherical shape and extended atmosphere. A more accurate inspection found out that the star was shaped more like a tear drop than a sphere. The VV Cephei A is supposed to go supernova soon and send its blue brother on a solo journey!
1. VY Canis Majoris
The undisputed king of the hill here is no doubt the most easily recognized star, VY Canis Majoris. This topper of the top 10 largest stars list is much less in density but has a whooping solar radii of 1800-2100. If set in place of our Sun, it would easily engulf all the space up till Saturn. Roughly 5000 light years away from us, VY Canis Majoris is also known as one of the brightest stars in our discovered universe. Many scientists are engaged in speculation over the type of death VY Canis Majoris is bound to have. Many state that will go off as a hyper nova and part of it will be converted into a black hole. The dissemination of VY Canis Majoris may light up the entire galaxy for up to 12 weeks!