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You can’t see millions of stars on a dark night. Despite what you may hear in TV commercials, poems and songs, you cannot see a million stars … anywhere. There simply are not enough close enough and bright enough. On a really exceptional night, with no Moon and far from any source of lights, a person with very good eyesight may be able to see 2000-2500 stars at any one time. (Counting even this small number still would be difficult.). So the next time you hear someone claim to have seen a million stars in the sky, just appreciate it as artistic license or exuberant exaggeration – because it isn’t true!

Astronomers estimate there are a trillion stars in the Milky Way Galaxy.

Stars are born in batches in their stellar nurseries. Over time, they travel through the Milky Way, far from their crèches.

Okay, this one you should know, but it’s pretty amazing to think that our own Sun, located a mere 150 million km away is average example of all the stars in the Universe. Our own Sun is classified as a G2 yellow dwarf star in the main sequence phase of its life. The Sun has been happily converting hydrogen into helium at its core for 4.5 billion years, and will likely continue doing so for another 7+ billion years. When the Sun runs out of fuel, it will become a red giant, bloating up many times its current size. As it expands, the Sun will consume Mercury, Venus and probably even Earth. Here are 10 facts about the Sun.

All stars begin from clouds of cold molecular hydrogen that gravitationally collapse. As they cloud collapses, it fragments into many pieces that will go on to form individual stars. The material collects into a ball that continues to collapse under its own gravity until it can ignite nuclear fusion at its core. This initial gas was formed during the Big Bang, and is always about 74% hydrogen and 25% helium. Over time, stars convert some of their hydrogen into helium. That’s why our Sun’s ratio is more like 70% hydrogen and 29% helium. But all stars start out with 3/4 hydrogen and 1/4 helium, with other trace elements.

Звукові хвилі потребують середовища для подорожі. Оскільки в вакуумі космосу немає атмосфери, царство між зірками завжди буде мовчати.

Нейтронні зірки можуть обертатися зі швидкістю 600 обертів в секунду
Нейтронні зірки – одна з можливих кінцевих точок еволюції зірок високої маси. Вони народжуються в результаті вибуху супернової зірки, яка згортається, і згодом надзвичайно швидко починає обертатися