Which star is the brightest in the sky? It depends on the season.

The night sky has captivated humanity for centuries, inspiring navigation techniques, cultural practices, religious traditions, and much more. Out of countless twinkling stars, a few stand out as particularly large and bright. But which is the brightest star in the sky?

The answer isn't so simple. Due to the Earth's rotation and axial tilt, the brightest star visible depends on whether you're in the northern or southern hemisphere and what season you're experiencing. The night sky shifts throughout the year, affecting a star's position, rise and set times, and how bright it appears to the observer.

That said, the inherent brightness of a star does not change based on where you are. Astronomers use a magnitude scale to measure star brightness, with lower numbers indicating brighter stars. This scale remains constant, whether or not the star is visible in your region.

To break it all down, let’s explore the brightest stars and when they are most visible in both the northern and southern hemispheres.

Sirius: Winter (Northern Hemisphere), Summer (Southern Hemisphere)

For astronomers, Sirius is undeniably the brightest star visible from Earth (excluding the Sun, of course). To determine a star's brightness, they use the magnitude scale, where lower numbers indicate brighter stars. Sirius has a magnitude of -1.46, the lowest magnitude of any star in the night sky.

From mid-December to February, Sirius takes center stage in the night sky. These months coincide with winter in the northern hemisphere and summer in the southern hemisphere.

Found in the constellation Canis Major (the Great Dog), Sirius is often referred to as the 'Dog Star.' At just 8.7 light years away, it is not only the brightest star but also the closest star to Earth (after the Sun).

How to Spot Sirius

Sirius can be seen from both hemispheres for several months each year, but it is most visible between December and February.

To locate Sirius in the northern hemisphere, look toward the southern horizon during winter evenings. If you spot Canis Major, Sirius is the brightest star in that constellation.

In the southern hemisphere, Sirius is seen high in the sky during the summer months.

Canopus: Winter to Spring (Southern Hemisphere)

By late spring in the southern hemisphere, Sirius is no longer visible as it has moved too close to the sun from our vantage point on Earth. This marks the time when a new star takes the spotlight in the southern sky: Canopus.

Situated in the constellation Carina (named after the keel of a ship), Canopus becomes visible across the southern sky in late summer and autumn. With a magnitude of -0.74, it ranks as the second-brightest star ever recorded by astronomers.

How to Spot Canopus

During the spring and summer months in the southern hemisphere, look for Canopus high in the sky.

In the northern hemisphere, Canopus is only visible near the horizon in the lowest latitudes, and the optimal time to observe it is February.

Alpha Centauri: Visible Year-Round (Southern Hemisphere)

While Sirius is often considered Earth's closest star (after the Sun), Alpha Centauri holds the distinction of being the closest star system to our planet, situated just 4.37 light years away. This system is made up of three stars: Rigil Kentaurus, Toliman, and Proxima Centauri.

Found within the Centaurus constellation (symbolized by the Centaur), Alpha Centauri boasts a combined apparent magnitude of -0.1, making it the third-brightest star visible from Earth.

How to Find Alpha Centauri

In much of the southern hemisphere, Alpha Centauri remains above the horizon throughout the night, making it visible nearly every clear evening. Look for the Southern Cross constellation. Its crossbar will point you toward a bright, yellowish star—Alpha Centauri.

While the star system isn't visible from most of the northern hemisphere, if you're in the far southern regions, it shines brightly near the horizon as a distinct point of light.

Arcturus: Spring (Northern Hemisphere)

Arcturus is a striking red giant star in the Boötes constellation, named after the Greek word for 'herdsman.' It's exceptional because there are no other prominent bright stars nearby in the night sky.

Arcturus, the fourth-brightest star with a magnitude of -0.05, is visible throughout the year in most of the northern hemisphere. It is especially noticeable between March and May, emitting an orange-red hue.

How to identify Arcturus

In the northern hemisphere, begin by finding the Big Dipper constellation: Its handle points directly toward Arcturus.

Arcturus is also visible in the southern hemisphere, but only during spring and summer.

Vega: Summer (Northern Hemisphere)

As summer arrives in the northern hemisphere, Vega rises to prominence. With a magnitude of 0.03, it's one of the brightest stars in the sky. Summer is the prime season to see it, although it can be spotted year-round in the northern hemisphere.

Vega is part of a renowned trio of bright stars: Along with Altair and Deneb (each from a different constellation), they form the Summer Triangle.

Vega, located in the Lyra constellation (also known as the Lyre or Harp), is approximately 25 light years from Earth.

How to Find Vega

To locate the star Vega in the northern hemisphere, look toward the northeast around mid-evening in May, or directly overhead after sunset in July.

In the southern hemisphere, Vega may be hard to observe because it doesn't reach its peak until around 3 or 4 a.m. If you're able to stay awake that late, May is the best time to see it.

Capella: Winter (Northern Hemisphere)

Capella, visible from late August to mid-June in the northern hemisphere, is most prominent in the winter months when it lights up the night sky. With a magnitude of 0.08, it ranks as the sixth-brightest star observed by astronomers and is part of the Auriga constellation, also known as The Charioteer.

Capella is unique as it isn't a single star but a quadruple star system, which includes two red giants. To observers on Earth, the star appears to shimmer with flashes of red, green, and blue as it rises or sets on the horizon.

How to Locate Capella

In the northern hemisphere, Capella can be found in the northeast during the early evening from mid-October to March.

In most parts of the southern hemisphere, Capella is not visible at all.

Rigel: Winter (Northern Hemisphere), Summer (Southern Hemisphere)

Rigel, a star in the Orion constellation, ranks among the brightest in the night sky. With a magnitude of 0.13, it stands as the seventh-brightest star visible to the naked eye.

Classified as a blue supergiant, Rigel is incredibly hot and bright, approximately 10,000 times more luminous than our Sun. This is why it appears so radiant from Earth, despite being located 863 light years away.

Spotting Rigel is easy once you've located Orion in the night sky, as Rigel marks the right leg of the hunter and sparkles with a blue-white glow.

How to Find Rigel

In the northern hemisphere during summer, Orion and Rigel can be seen rising in the east just before dawn. However, the view is even more stunning on winter nights when it appears high in the southern sky.

In the southern hemisphere, Rigel can be found high above on summer nights. During January and February, it becomes visible right after sunset.