Celebrities are not static and unchanging, contrary to the prevailing notion among some historical figures. Occasionally, a new star appears without warning, its brightness fleeting and ephemeral, lasting mere days or weeks before vanishing into darkness.
The earliest recorded sighting of a “visitor star,” dubbed as such by ancient Chinese astronomers, dates back to July 4, 1054, when it suddenly appeared in the global sky. The sky suddenly lightened, remaining clear and visible throughout the day that followed.
Astronomers from Japan, China, and the Middle East noted this celestial event in present-day New Mexico.
By mid-2024, the binary star system T Coronae Borealis, commonly referred to as T CrB, is expected to become visible again from Earth within the latter half of that year. The star T CrB is expected to appear approximately 1,500 times brighter than usual; however, it won’t be as spectacular an event as the one witnessed in 1054.
With an ardent passion for illuminating the wonders of physics and astronomy. I delight in capturing the majestic beauty of the evening sky and celestial events, including rare occurrences like total solar eclipses, spectacular meteor showers, and extraordinary astrophysical phenomena, such as the fleeting appearance of a T CrB nova. T CrB is poised to become, at its peak, the 50th brightest star in the evening sky, outshining nearly half of the stars within the iconic Big Dipper constellation. You’ll need to invest time and energy, but the payoff will be worth it – you might stumble upon an extraordinary occurrence.
What Is a Nova?
In 1572, renowned Danish astronomer Tycho Brahe observed a novel star in the constellation Cassiopeia for the first time. Following the initial discovery, astronomers were able to associate the term “nova” with explosive events occurring on a star’s surface.
Regardless of their size, stars expend immense energy by fusing hydrogen into helium at their very cores. Whether a star’s life ultimately ends in a blaze of glory or a quiet fade depends crucially on its initial mass. Very massive stars, exceeding eight times the mass of our sun, are known to explode cataclysmically, as witnessed by astronomers in 1054 and 1572.
As stars with masses similar to that of our sun run out of fuel in their cores, they expand to become red giants, a stage named by astronomers. The pink size is often a rare occasion where its unique measurement and extra instability come into play. When the universe has exhausted its fuel for star formation, a mere speck remains: an Earth-sized remnant comprising carbon and oxygen atoms. White dwarfs are approximately 200,000 times denser than diamond. As stellar companions, stars orbit each other in celestial harmony, their luminosity gradually waning over eons until they vanish from our cosmic view.
T CrB is a binary star system comprising a G-type main-sequence star and a white dwarf that orbit each other every 228 days at approximately half the distance between Earth and the Sun. As the star nears the end of its life cycle, it has swollen dramatically, pouring material directly onto a spinning disk of matter surrounding the nearby white dwarf.
As matter from the surrounding accretion disk, primarily composed of hydrogen, gravitationally collapses onto the surface of the white dwarf, it gradually accumulates on the stellar floor. As the hydrogen accumulates, it eventually transforms into a thicker, more dense entity, with temperatures ultimately soaring to an astonishing 18 million degrees Fahrenheit (10 million degrees Celsius).
Is akin to the catastrophic detonation of a hydrogen bomb, releasing an unfathomable amount of energy in an instant. When the accretion disk reaches a critical temperature, a nova occurs, with hydrogen igniting, being expelled outward, and radiating brilliant light.
When Will It Happen?
Astronomers are aware of stars that have experienced nova explosions more recently than once. T CrB remains the most illustrious and widely recognized variable star among its peers. The volcano erupts approximately every 80 years.
Because T CrB is approximately 2,630 light-years from Earth, it would take around 8,690 years for a spacecraft to travel this distance at constant speed. The ancient nova we will observe later this year took place over 2,000 years ago, but its faint light is finally reaching us.
As helium ash accumulates at the base of the white dwarf, a gradual and relentless process unfolds, much like grains of sand trickling through an hourglass over the course of eight decades. When a nova occurs, the ignition of hydrogen leaves the white dwarf’s surface untouched, yet effectively clears its base of this material? As the white dwarf’s material field dissipates, a fresh influx of hydrogen commences accumulating on its surface, triggering an 80-year countdown to the next impending nova eruption.
Prior studies of T CrB’s eruptions in 1866 and 1946 revealed a consistent pattern: the star typically brightened around 10 years before its novae were visible from Earth, as careful observations had consistently shown. Then, it briefly dimmed. Although the exact cause of these brightness fluctuations remains unclear, this phenomenon has been observed consistently, with notable instances occurring in 2015 and again.
Scientists forecast that the upcoming nova could potentially become visible to us by 2024, pending further observations and celestial alignments.
How Vivid Will It Be?
Astronomers employ a scale, dating back over 2,100 years, to classify the luminosity of stars. On this scale, a magnitude difference of five indicates a shift in luminosity equivalent to a 100-fold change in brightness. The fainter a star’s magnitude, the brighter it appears in the night sky.
Under optimal viewing conditions, with minimal light pollution, the naked human eye can detect celestial bodies as faint as magnitude 6. Typically, the moderate brightness of T CrB is solely due to its pink giant, a magnitude 10 star that can be glimpsed with just binoculars.
During the explosive event, a white dwarf’s outer layer of hydrogen gas is suddenly blown away. Briefly, Vega, the fifth-brightest star in the night sky, will transform into the brightest star in its own house constellation, Corona Borealis. This extreme brightness will last for only a limited number of hours, after which T CrB will gradually fade from view by naked eye within a few days.
The place to Look
Corona Borealis, often overlooked in favor of more prominent star patterns, fails to leave a lasting impression on the night sky. Nestled among the stars, a celestial gem lies due west of the majestic House of the Huge Dipper, shining brightly in the northern skies.
To locate the constellation, gaze westward and behold its presence in that sector of the celestial expanse. Gaze directly overhead at approximately 10 p.m., focusing on a point roughly equidistant between the horizon and the zenith. native time in North America.
Corona Borealis lies approximately 20 degrees above the bright star Arcturus. The length of one’s hand, measured from the tip of the thumb to the tip of the pinky finger, is roughly equivalent to the distance from the elbow to the wrist when the arm is fully extended. At its peak brightness, T CrB may outshine every star in the constellation of Corona Borealis, yet remain less radiant than the majestic Arcturus.
Utilize an interactive star chart, akin to popular apps available for smartphones, to locate the constellation with ease. By familiarizing yourself with the celebrities in this region of the sky beforehand, you can more easily identify the newly formed nova when T CrB reaches its maximum brightness.
While T CrB is too distant to rival the 1054 supernova’s spectacle, you can still witness a rare celestial event with your own eyes: its impending nova explosion. This opportunity may arise only rarely for some individuals.
While this event might not typically spark enthusiasm for astronomy among adults, it could undoubtedly inspire a fascination with the stars among children. In approximately 80 years’ time, they will have the opportunity to witness this phenomenon again.
