Fomalhaut is a young, hot, and luminous star, larger, brighter, and more massive than our Sun, located just 25 light-years away. In the autumn, it becomes easily visible in the southern sky, particularly between 7 and 8 PM in November. Fomalhaut is part of the Southern Fish constellation and is among the top twenty brightest stars visible from Earth. It has a surface temperature of 8,500 Kelvin and is surrounded by a vast ring of dust, where a potential exoplanet, Fomalhaut b, has been observed, although its classification remains uncertain. Recent research using advanced telescopes continues to explore its complex structure.
Fomalhaut is a young, hot star—larger, brighter, and heavier than our Sun. This celestial body is also quite close to us, making it a near neighbor in the cosmos. During the autumn months, Fomalhaut is especially easy to spot.
If you gaze towards the southern horizon on an autumn evening, you will notice a bright, prominent star just above the horizon. This star is Fomalhaut, the brightest star in the constellation Piscis Austrinus, and ranks among the top twenty brightest stars visible from Earth. In Germany, there are only about a dozen stars visible that outshine Fomalhaut.
As implied by its name, the constellation Piscis Austrinus is typically associated with the southern hemisphere. Although stars from the southern sky cannot be seen from the North Pole, Germany’s position allows for several southern stars to be visible at various times throughout the year.
Autumn Evenings Perfect for Viewing Fomalhaut
Autumn provides an excellent opportunity to spot Fomalhaut. Unlike summer when it rises in the early morning hours, during fall, it appears in the early evening. In November, this star reaches its highest point in the southern sky between seven and eight o’clock at night.
However, Fomalhaut doesn’t rise too high above the horizon; in southern Germany, it is only about a hand’s breadth above it. The further north you go, the lower it appears in the sky.
For those unfamiliar with its name, now is the perfect time to discover this remarkable star.
How to Locate Fomalhaut
To find Fomalhaut, you can begin by locating the Great Square of Pegasus, which is an easily recognizable shape high in the southern sky during autumn. By extending a line from the two rightmost stars of Pegasus down towards the horizon, you will directly point to Fomalhaut.
Being just above the horizon can be a disadvantage for viewing; it requires an unobstructed line of sight and is affected by atmospheric distortion. When viewed from the equator, where Fomalhaut hangs higher in the sky, it shines even brighter.
The layers of the atmosphere are responsible for causing Fomalhaut to shimmer in various colors. In reality, this star emits a steady, bright white light.
Meanwhile, the comet C/2023 A3 Tsuchinshan-ATLAS is getting brighter and may soon be visible to the naked eye.
A Young, Hot, and Bright Star
Fomalhaut is considered a young and fiery sun, estimated to be about 400 million years old. In contrast, our Sun has been shining for approximately 4.5 billion years—over ten times longer. Fomalhaut’s diameter is nearly double that of our Sun, and it has 2.5 times more mass. Additionally, Fomalhaut is much hotter, with a surface temperature of 8,500 Kelvin, compared to the Sun’s 5,800 Kelvin (around 6,000 degrees Celsius), making Fomalhaut 17 times more luminous than our Sun.
One of the reasons for Fomalhaut’s brightness is its relative proximity to Earth; it lies just 25 light-years away, meaning its light takes 25 years to reach us. For comparison, the nearest star, Proxima Centauri, is 4.2 light-years away, and Sirius in the Canis Major constellation is nearly 9 light-years distant. Other visible stars may be thousands of light-years away.
Though Fomalhaut has been known since ancient times, it has regained research interest in the last two decades due to its proximity, which allows for easier observation.
Researchers in Heidelberg using the James Webb Space Telescope have recently discovered a new exoplanet.
Is There an Exoplanet Fomalhaut b?
Fomalhaut is encircled by a massive dust disk, measuring about forty billion kilometers in diameter. In 2008, the Hubble Space Telescope identified a striking structure within this disk that astronomers initially believed to be an exoplanet, naming it ‘Fomalhaut b.’ Since then, it has been closely monitored.
However, there are growing doubts about whether this structure is actually a planet. The object orbits Fomalhaut in a highly eccentric manner and appears to be moving farther away, becoming increasingly dim. It could simply be a dust cloud resulting from a collision between two smaller bodies. Alternatively, there’s a model suggesting that Fomalhaut b might indeed be a planet, possibly accompanied