Romantics who entrust their wishes and dreams to the stars in the sky in the hope that they will come true, please do not believe the spoilsports who say that doing so is useless because those stars are actually already dead. They are much more likely to be alive and well and to be that way for a long time (unlike the rest of us). Here’s why.
We’re not that far away
It is true: the starlight that our eyes perceive comes from afar and, therefore, despite traveling at a speed of almost 300 million meters per second, takes a long time to arrive. The question is how likely it is that during that time the star emitting the light has died. The truth is that, if the star is visible to the naked eye, the opposite is much more likely, that is, that it is alive.
Magnitude is the unit of measurement of a star’s brightness. and it decreases the brighter it is. For example, the brightest star in the Southern Cross has a magnitude of 0.8, while the dimmest star in the same constellation reaches 3.6. Well: in fact, even the stars that are in the limit of visibility for the human eyethat is, those that have a magnitude of 6.5are located at a distance of about 10,000 light years of our planet. In astronomical terms, this means that even the most distant visible stars are very close to us. Of course, we know more distant stars, but they are not those that can be seen with the naked eye, but rather those that we only perceive with the help of supertelescopes.
So, even assuming that we have directed our hopes to one of the most distant stars we can see, and assuming that desires travel at the same speed as light, the star of Our heart, when it receives the wish, will be at most 20 thousand years older than the age it was when it emitted the light that we just saw. And, again, 20 thousand years in astronomical terms is almost nothing.
The visible stars of the Milky Way belong to the category of stars giants, subgiants, or, to the so-called stars main sequence. Of these, the less long-lived They are giant stars, but their half-life is (at least) a few hundred thousand years: Therefore, it is unlikely that in 20 thousand years they will no longer be there.
Don’t risk it
And if you really don’t want to risk it, suggests University of Sydney astronomer Laura Nicole Driessen in The Conversationhere are the best stars to pay attention to: Alpha Centaurithree stars that are only 4 light years away from us and that still have a long time ahead of them; Siriusthe brightest star in the night sky that is only 8.6 light years away and only halfway through its life; Epsilon Eridaniwhich, like Sirius, will still burn for millions of years. And finally, the star closest to us, the Sun just 8 light minutes away: a guarantee.
Article originally published in WIRED Italyadapted by Manuel de León.
#probability #stars #shining #sky #dead
