The red hypergiant VY Canis Majoris is enshrouded in substantial clouds of dust
Stars been available in a remarkable variety of sizes. One of the most gigantic is VY Canis Majoris. If put in the middle of our planetary system it would swallow up all the worlds out to Saturn’s orbit. This beast, properly called a red hypergiant, is as intense as 300,000 Suns. Yet it is up until now away that, 200 years back, it might be seen just as a faint star in the winter season constellation of the Great Dog. Since then, it has actually faded and is no longer noticeable to the naked eye. Astronomers utilized Hubble to get a close-up take a look at the star and found the factor for the dimming. The star is expelling substantial clouds of dust in the lasts of its life. Eventually, the puffed up star might take off as a supernova, or might just collapse and form a great void.
Last year, astronomers were puzzled when Betelguese, the intense red supergiant star in the constellation Orion, considerably faded, however then recuperated. The dimming lasted for weeks. Now, astronomers have actually turned their sights towards a beast star in the adjacent constellation Canis Major, the Great Dog.
The red hypergiant VY Canis Majoris—which is far bigger, more enormous, and more violent than Betelgeuse—experiences a lot longer, dimmer durations that last for several years. New findings from NASA’s Hubble Space Telescope recommend the exact same procedures that took place on Betelgeuse are occurring in this hypergiant, however on a much grander scale.
“VY Canis Majoris is behaving a lot like Betelgeuse on steroids,” discussed the research study’s leader, astrophysicist Roberta Humphreys of the University of Minnesota, Minneapolis.
As with Betelgeuse, Hubble information recommend the response for why this larger star is dimming. For Betelgeuse, the dimming represented a gaseous outflow that might have formed dust, which quickly blocked a few of Betelgeuse’s light from our view, producing the dimming result.
“In VY Canis Majoris we see something similar, but on a much larger scale. Massive ejections of material which correspond to its very deep fading, which is probably due to dust that temporarily blocks light from the star,” stated Humphreys.
The huge red hypergiant is 300,000 times brighter than our Sun. If it changed the Sun in our own planetary system, the puffed up beast would extend out for numerous countless miles, in between the orbits of Jupiter and Saturn.
“This star is absolutely amazing. It’s one of the largest stars that we know of—a very evolved, red supergiant. It has had multiple, giant eruptions,” discussed Humphreys.
Giant arcs of plasma surround the star at ranges from it that are countless times further away than the Earth is from the Sun. These arcs appear like the solar prominences from our own Sun, just on a much grander scale. Also, they’re not physically linked to the star, however rather, appear to have actually been tossed out and are moving away. Some of the other structures near the star are still reasonably compact, appearing like little knots and ambiguous functions.
In previous Hubble work, Humphreys and her group had the ability to figure out when these big structures were ejected from the star. They discovered dates varying over the previous numerous a century, some as just recently as the past 100 to 200 years.
Now, in brand-new deal with Hubble, scientists dealt with functions much better to the star that might be less than a century old. By utilizing Hubble to figure out the speeds and movements of the close-in knots of hot gas and other functions, Humphreys and her group had the ability to date these eruptions more precisely. What they discovered was exceptional: a lot of these knots connect to numerous episodes in the 19th and 20th centuries when VY Canis Majoris faded to one-sixth its normal brightness.
Unlike Betelgeuse, VY Canis Majoris is now too faint to be seen by the naked eye. The star was as soon as noticeable however has actually dimmed a lot that it can now just be seen with telescopes.
The hypergiant sheds 100 times as much mass as Betelgeuse. The mass in a few of the knots is more than two times the mass of Jupiter. “It’s amazing the star can do it,” Humphreys stated. “The origin of these high mass-loss episodes in both VY Canis Majoris and Betelgeuse is probably caused by large-scale surface activity, large convective cells like on the Sun. But on VY Canis Majoris, the cells may be as large as the whole Sun or larger.”
“This is probably more common in red supergiants than scientists thought and VY Canis Majoris is an extreme example,” Humphreys continued. “It may even be the main mechanism that’s driving the mass loss, which has always been a bit of a mystery for red supergiants.”
Though other red supergiants are comparably intense and eject a great deal of dust, none is as complex as VY Canis Majoris. “So what’s special about it? VY Canis Majoris may be in a unique evolutionary state that separates it from the other stars. It’s probably this active over a very short period, maybe only a few thousand years. We’re not going to see many of those around,” stated Humphreys.
The star started life as a super-hot, dazzling, blue supergiant star maybe as much as 35 to 40 times our Sun’s mass. After a couple of million years, as the hydrogen blend burning rate in its core altered, the star inflated to a red supergiant. Humphreys thinks that the star might have briefly went back to a hotter state and after that swelled back up to a red supergiant phase.
“Maybe what makes VY Canis Majoris so special, so extreme, with this very complex ejecta, might be that it’s a second-stage red supergiant,” discussed Humphreys. VY Canis Majoris might have currently shed half of its mass. Rather than blowing up as a supernova, it may just collapse straight to a great void.
The group’s findings appear in the February 4, 2021 edition of The Astronomical Journal.
Reference: “The Mass-loss History of the Red Hypergiant VY CMa*” by Roberta M. Humphreys, Kris Davidson, A. M. S. Richards, L. M. Ziurys, Terry J. Jones and Kazunori Ishibashi, 4 February 2021, The Astronomical Journal.
The Hubble Space Telescope is a task of worldwide cooperation in between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, handles the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, performs Hubble science operations. STScI is run for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.