As an expert in astronomy, I can tell you that the concept of the "brightest star in the world" is a bit misleading. The brightness of a star can be measured in two ways: its intrinsic brightness, known as luminosity, and its apparent brightness as seen from Earth.

The luminosity of a star is determined by its energy output and is independent of its distance from us. The most luminous star known is Rigel, a blue-white supergiant in the constellation Orion. However, due to its great distance from Earth, it is not the brightest star in our night sky.

When we talk about the apparent brightness, which is the brightness of a star as observed from Earth, we are considering both the star's luminosity and its distance from us. The star that appears brightest to the naked eye is Sirius, often referred to as the "Dog Star." Sirius is a white main-sequence star in the constellation Canis Major and is almost 8.6 light-years away from Earth. Its apparent brightness is due to its relatively close proximity to us and its high intrinsic luminosity.

So, to answer your question accurately, Rigel is the most luminous star known, but Sirius is the brightest star in the night sky as seen from Earth.

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The brightest star in the sky is Sirius, also known as the ��Dog Star�� or, more officially, Alpha Canis Majoris, for its position in the constellation Canis Major. Sirius is a binary star dominated by a luminous main sequence star, Sirius A, with an apparent magnitude of -1.46.read more >>