Which star is known as the brightest star in the night sky?

Sirius is recognized as the brightest star in the night sky, primarily due to its intrinsic luminosity and its relatively close proximity to Earth, located about 8.6 light-years away in the constellation Canis Major. Its brightness is measured in terms of apparent magnitude, a scale that quantifies how bright a star appears from our perspective on Earth. Sirius has an apparent magnitude of about -1.46, making it not only brighter than other stars but also visible even in light-polluted urban environments.

In addition to its brightness, Sirius is a binary star system, consisting of the main-sequence star Sirius A and its companion, Sirius B, which is a white dwarf. The significant luminosity of Sirius A contributes greatly to its overall brightness in our sky. The combination of both physical properties—its effective temperature (approximately 9,940 K) and its mass (about twice that of our Sun)—plays an essential role in adding to its visibility.

The other stars mentioned, while notable in their own right, do not match Sirius in apparent brightness when viewed from Earth.