Red giant and white dwarf: Nova explosion in the northern crown witnesses the emergence of a ‘new’ star.

In this animation of a nova, a red giant star and a white dwarf engage in a mesmerizing cosmic dance. The red giant, a vast sphere adorned in shades of red, orange, and white, orbits the white dwarf. The side facing the white dwarf exhibits the lightest shades. Meanwhile, the white dwarf remains concealed within a radiant glow of white and yellows, forming an accretion disk around the star. A diffuse cloud of red represents the stream of material flowing from the red giant to the white dwarf. The animation unfolds with the red giant co-orbiting on the right side, eventually moving behind the white dwarf.The animation unfolds with the red giant co-orbiting on the right side, eventually moving behind the white dwarf. As the red giant disappears, a spectacular nova explosion ignites on the white dwarf, flooding the screen with intense white light. Following the luminous display, a ball of ejected nova material emerges in pale orange hues. Amidst the clearing fog of material, a small white spot persists, indicating the survival of the white dwarf after the explosive event.

A celestial spectacle awaits as a star system, situated 3,000 light-years away, is poised to become visible to the unaided eye in what could be a rare viewing opportunity. Anticipated between February and September 2024, the nova outburst of T Coronae Borealis (T CrB) occurs approximately every 80 years, and its last explosion was witnessed in 1946. The star system, typically with a magnitude of +10, too dim for unaided observation, is expected to surge to magnitude +2 during the event—comparable in brightness to the North Star, Polaris.

Following its peak brightness, this cosmic event is projected to be visible to the naked eye for several days and extend just over a week with binoculars before fading, possibly for another 80 years. To fully appreciate this celestial phenomenon, enthusiasts are encouraged to acquaint themselves with the constellation Corona Borealis, or the Northern Crown—a small, semicircular arc near Bootes and Hercules—where the outburst will manifest as a “new” bright star in the cosmic tapestry.

Embark on a celestial quest with this conceptual image guiding you to discover Hercules and his majestic globular clusters in the night sky. Utilizing planetarium software, the image provides a visual roadmap for stargazers. To locate Hercules, simply gaze upward after sunset during the summer months, scanning between Vega and Arcturus, near the distinctive pattern of Corona Borealis. Once Hercules reveals its stars, enhance your celestial exploration with binoculars or a telescope to pinpoint the captivating globular clusters M13 and M92. If the allure of these clusters captivates you, extend your cosmic journey by seeking out another splendid globular, M3, nestled in the neighboring constellation of Boötes. Happy stargazing!

The recurrent nova, T Coronae Borealis (T CrB), stands as one of merely five such phenomena within our galaxy. This celestial recurrence results from the unique dynamics of T CrB, existing as a binary system with a white dwarf and a red giant in close proximity. As the red giant undergoes instability due to escalating temperature and pressure, it initiates the expulsion of its outer layers. The white dwarf, positioned nearby, efficiently collects this ejected material onto its surface.

Over time, the shallow yet dense atmosphere of the white dwarf reaches a critical temperature, triggering a runaway thermonuclear reaction. This reaction manifests as the dazzling nova phenomenon observable from Earth, offering a mesmerizing glimpse into the intricacies of celestial interactions within binary star systems.