One of the most popular red hypergiants in the galaxy is the VY Canis Majoris found in the constellation Canis Major. Discovered in 1801 by Jerome Lalande, it was listed at the time as a 7th magnitude star. The really disappointing fact about Canis Majoris is that it has been dying since its discovery, but something that red hypergiants this big are used to. At one point it was the largest star in the galaxy but has since been surpassed by several other discoveries. There was also a controversy about the whether it was a multiple star, a myth that was debunked in both 1957 and 1998 respectively. Even in its fading state there is a lot of interesting scientific data to be collected from this star, and it gets even more interesting since you can only see it with a telescope.
Largest Star In The Galaxy?
At one point VY Canis Majoris was known as the largest star in the galaxy. Time has since passed it by, and besides it shrinking each and every year, more stars and objects have been discovered that take its place.
UY Scuti is another red supergiant but one that rests in the constellation Scutum. Besides being larger it is also more luminous than VY Canis Majoris. With a volume 5 billion times that of the sun, this is one star that we don’t want to have an explosive supernova anytime soon. Discovered in 1860 by German astronomers, it continues to be studied and may be even larger than we expect.
Part of the Cygnus OB2 association, the NML Cygni is a red hypergiant that was recently discovered in 1965 by a trip of scientists. Because of the brightness regulations, it has been given the designation V1489. Besides being neighbors with the Sun, there is a lot that people still don’t know about this star. Well, other than that it is one of the largest in the galaxy!
The largest star in the LMC is the WHO 64, a red hypergiant that can be found in the southern constellation of Dorado. With the ability to engulf Jupiter if it was placed at the center of the solar system, this is one massive star that has intrigued scientists since its discovery in 1970. Interested beginner astronomers should expect this discovery to continue to be monitored over the next few years.
As the first orange hypergiant on the list, the RW Cephei exists in the constellation Cepheus. With an estimated solar radii of 1,636 it varies on many levels in temperature switches between being a red supergiant and a yellow hypergiant. It is a very confusing star for the beginning astronomer, but very easy to find.
Is it Dying?
The red hypergiant may be having its final swan song sooner rather than later. Stars the size of Canis Majoris tend to have short lives due to the amount of nuclear fuel they burn. The steady reaction with gravity causes a push and pull effect that is a lot more exciting that watching paint dry, but also immensely intense once it decides to gives way. With it losing up to 30 times its mass each year due to this push and pull effect, it is amazing that it has lasted this long without exploding.
Astronomers still haven’t exactly figured out in detail how a star dies, but knowing that a supernova explosion is in its future has some people worrying on earth if any of the fragments will enter our atmosphere. There isn’t much to worry due to how far away it is, but people will be able to see the explosion from earth, even without a telescope. It will be an incredible lightshow, and one that isn’t expected to happen for thousands of years from now. So even though it is dying, in our current lifetimes and generations after, it will be very much alive and bright.
Interesting Notes About VY Canis Majoris
The idea of this massive star exploding and shattering Earth has more science fiction in it than an episode of Star Trek-but it is still a valid concern, nevertheless. It’s only 4,000 lightyears away from Earth, so a blowback of some kind when it dies is very much possible. With a radius that is 1,500 times larger than the Sun, the Sun by comparison looks like its little kid brother. As a scary thought, the supernova explosion caused by the death of VY Canis Majoris could potentially create a black hole, sucking in everything within its reach.
The VY Canis Majoris is one of many reasons to own a telescope and get into astronomy. Even with some of the scary facts surrounding it in the next thousand or so years, it is still one of the most interesting stars in our entire solar system.