When is a star a sun?

A starry sky is often a sight to behold. But are the twinkling celestial bodies all suns at once? That question divides experts.

Frankfurt – Without the sun, humanity would perish. It illuminates the world, provides light, and its appearance in a blue, cloudless sky usually puts you in a good mood. Night owls also get their money’s worth when they look up at the sky. Not always, but often a constellation of very bright stars can be admired. The twinkling celestial bodies clearly have the same appearance, but they differ greatly upon closer examination. That is precisely why the sun is a star. The reverse question immediately arises: is every star a sun? Firstly: there are no generally valid definitions.

Countless stars, but also several suns? – Classification does it

For the stars However, yes. The hot hydrogen balls inside glow and then begin to glow. Observers on Earth can then see this. The energy source of stars is the nuclei of hydrogen atoms, just like the Sun. The Sun, being the closest star to Earth, is called the “Sun” because it has such an important and undeniable effect on Earth. IFL Science He writes.

Since the “deplanetization” of Pluto and the finding of names such as dwarf planets, controversy has erupted over this classification time and time again. Especially after celestial bodies that appear to be unimpressive and dull in appearance were called moons, even though they do not have the same effect as Earth's moon.

If we continued this line, every star would be a sun. But it's not that simple. White dwarfs, for example, are “dead.” They only radiate residual heat, so they live with a fairly quick expiration date. They therefore lack the “sun” property of nuclear fusion.

Special case with Venus? Absolutely.

This is especially the case with Venus. It is the third brightest planet in our solar system and is often referred to as “morning” or “evening star” Certain. Incorrectly. Because just because Venus shines, it is not a star, it is a planet.

By definition, a star must shine on its own. Venus can't do that, and Earth's neighbor is relatively cool, with an average temperature of just over 460 degrees Celsius, according to data from NASA. German Weather Service It appears. The coldest stars still have a massive surface temperature of 2,500 degrees Celsius, so European Space Agency It carries on. The other planets can only be seen by the human eye when the stars illuminate these planets.

Meanwhile, exoplanets are a completely different species in their own right. They have their own star or brown dwarf that they orbit. Essentially, their own sun is the driving force behind their creation and existence. So the star is an essential component of the exoplanet's “life.” Just as the sun does for Earth. It is up to the observer to decide whether sun-like stars are “worthy” of the name sun. (Please)