NASA REVEALS THE CHANCE OF SEEING A STAR EXPLOSION WITH THE NAKED EYE
This year's astronomical events are really exciting. A significant portion of North America will witness a total solar eclipse in a few weeks, and it might also include a green "devil comet." NASA has now disclosed that there will be another stellar event later this year. Between now and September, the star system T Coronae Borealis, or T CrB, is expected to undergo a nova outburst that would make it visible to the unaided eye.
As the nova outburst of T CrB was last observed in 1946, this could be a once-in-a-lifetime opportunity, as it only happens approximately every 80 years. The system is 3,00 light-years from Earth, and its light is typically too faint to see without a telescope, at a magnitude of +10. Nevertheless, the nova will increase in brightness to magnitude +2, which is comparable to that of Polaris, the North Star.
A nova only removes the outer layers of accumulated material; in contrast, a supernova signifies the end of a star's life. We have a rare opportunity to witness the star as its luminosity is momentarily increased by several thousand times due to the energy it exudes.
According to NASA, "After it peaks in brightness, it should be visible for several days with unassisted vision and just over a week with binoculars before it dims again, possibly for another 80 years." T CrB is one of only five recurring novas in our galaxy, and it novaes every 80 years due to its structure as a binary system consisting of a red giant and white dwarf.
According to NASA, "the stars are close enough that the white dwarf collects that matter onto its surface as the red giant becomes unstable due to its increasing temperature and pressure and begins ejecting its outer layers."
“The shallow dense atmosphere of the white dwarf eventually heats enough to cause a runaway thermonuclear reaction—which produces the nova we see from Earth.”
T Coronae Borealis is a member of the Northern Crown, or Corona Borealis constellation, as its name implies. It is visible as a tiny, semicircular arc close to Hercules and Bootes. The nova will appear as a "new" bright star when it occurs. "During the summer, look up after sunset to find Hercules," advises NASA. "Scan close to the distinctive Corona Borealis pattern, between Vega and Arcturus."
Astronomy Magazine was told by Louisiana State University professor emeritus Bradley Schaefer that "this is the one big chance you have of seeing the brightest nova of the generation." It's important to stay informed and keep an eye on T CrB since, as he points out, it could go up any night or month from now.