NASA has announced that a unique star system located 3,000 light-years away from Earth will provide us with a unique celestial spectacle that can be seen with the naked eye during 2024. T Corona Borealis, becomes visible between March and September 2024, due to a nova explosion. No telescope will be needed to observe this spectacular cosmic spectacle, in which T CrB will glow to match the luminosity of Polaris, a phenomenon resulting from the cosmic dance between a white dwarf and a red giant.
Right now the star system, normally magnitude +10 and therefore too faint to be seen with the naked eye, it jumps to magnitude +2 during the event.
Unique opportunity: Astronomers predict nova 3,000 light-years away will be visible to the naked eye
Astronomical peculiarities
T CrB is a recurrent nova system, an astronomical oddity consisting of two stars caught in a gravitational tang: white dwarf and red giant. A remnant of a star about the size of Earth but with a mass close to that of our Sun, a white dwarf is the dense core left over from a star that has shed its outer layers. A red giant, a star later in its life that has expanded and cooled, is still burning helium at its core and has a huge, billowing atmosphere.
As the white dwarf orbits each other, the intense gravitational pull pulls material (mainly hydrogen) from the red giant’s vast atmosphere. This stolen gas creates a spiral accretion disk as it approaches the white dwarf and it finally falls to its surface. When enough hydrogen accumulates on the surface of a white dwarf, the pressure and temperature rise, triggering a thermonuclear explosion that causes the system to glow dramatically. Scientists call this explosion a nova.
Novas can be impressive and scientifically significant, and T Coronae Borealis (T CrB) is one of the best.
Help in manuscript
One of the curiosities of this next event is that in 1866Astronomers were shocked when a star that previously required telescopes quickly became the second brightest in the constellation Coronae Borealis for several weeks; a detail that appeared earlier detailed in a medieval manuscript which shows the brightness of what could be the same star and which we hope to see again soon, precisely in 2024. Once its brightness reaches its peak, it should be visible with the naked eye for several days and for a little more than a week with a telescope, before it gets dark again.
Between 1866 and 1946, however, the white dwarf stole enough material from its companion to light up the system as a whole approximately a thousand times until it reached third magnitude. This is why it is known as a repeating nova. Pairs in which this occurs are often known as recurring novae, which typically explode at regular intervals. T CrB last exploded in 1946, and astronomers believe it will do so again in the coming months. (According to experts, historically CrB explodes approximately every 80 years).
T CrB became famous not only for its status as a recurring nova, but also for the historical records of its explosions.
Where to look?
Commenting on NASA’s statement where should we look in the sky when this event occurs. “While we wait for the new moon, familiarize yourself with the constellation Corona Borealis, or Northern Crown, a small semicircular arc near Bootes and Hercules.” “That’s where the burst appears as a ‘new’ bright star.”
T CrB is quite close than other recurring novae V94 Southern crownwith; At 2,600 light-years away, it is close enough to be among the 200 brightest stars during the last two flares.
Professor Bradley Schaefer of Louisiana State University recently provided evidence for a date near April 2024 for a “new” recurring nova. She used the timing of the decline in brightness before the eruption rather than the duration of the previous interval to determine when to expect the next event. Others predicted a mid-2025 event. We won’t have to wait long to find out if this prediction is correct or not.
Anticipating the next big nova display.
Recurring novae of our galaxy
This recurring nova is only one of five in our galaxy. There are several, for example:
RS Ophiuchus: a well-studied repeating nova system that has seen flares in 1898, 1933, 1958, 1967, 1985, and most recently in 2006. The system consists of a white dwarf and a red giant, with a particularly short recurrence period estimated at about 15 to 20 years. The interaction between the red giant’s stellar wind streams and the white dwarf’s intense gravity leads to periodic accretion of material and subsequent thermonuclear escapes.
Scorpion (The Sco): one of the most rapidly recurring novae known, with a recurrence period of approximately 10 years and eruptions recorded in 1863, 1906, 1936, 1979, 1987, 1999 and 2010. This one is notable for its rapid brightness and equally rapid decrease in brightness. The system consists of a white dwarf and a massive main-sequence star, with the white dwarf located near the Chandrasekhar limit, making U Sco a potential Type Ia supernova candidate.
CI Aquila (CI Aql): They have known eruptions in 1917, 1941 and 2000. The system consists of a white dwarf and a slightly evolved companion star. CI Aql’s eruptions are of particular interest because they allow astronomers to study changes in the accretion disk and the rate at which the white dwarf is accreting matter from its companion.
Recurring novae exist because white dwarfs are much hotter and denser than most main sequence stars.
Reference:
- View Nova Explosion, ‘New’ Star in Northern Crown 2024 NASA Press Release Lauren Perkins
- NASA’s Marshall Space Flight Center
