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Asked by anon-267532 to Zsolt on 4 Nov 2020.
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Zsolt Keszthelyi answered on 4 Nov 2020: last edited 4 Nov 2020 4:16 pm
Great question!
There are two main approaches. One is to observe them, which requires telescopes or other instruments (for example, gravitational-wave detectors or neutrino detectors). These observations help us understand the properties of stars. Actually, you can also do observations just by looking at the night sky. Try to see if you can distinguish the colour of shiny bright dots (a.k.a. stars) in the sky. The ones that look bluer are stars that are hot, the ones that look red are stars that are cool. This is because the surface temperature of the star impacts the colour in which you can see them.
The other approach is theory, which nowadays is mostly very efficient computer simulations. This way you can study processes that take place in stars, for example, convection. Did you ever heat up water on the stove to make pasta? If so, you have certainly seen rising hot bubbles in the water. This is caused by convection. The same process takes place in stars, but instead of the stove, stars have nuclear fusion to generate energy, and instead of water, stars are made of mostly hydrogen and helium. So the ingredients change but the physics is the same. Yet another way to study stars is to design computer simulations which will model the evolution of stars. In reality, the evolution of stars takes over millions of years, but with computer simulations, you can speed up this evolution and see the past and future of your star model in just a few minutes. This is important because with such models we can try to understand what will happen to the Sun and other stars in the future.
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Comments
anon-267532 commented on :
thanks for answering, i really like seeing the star so i had the question.
Zsolt commented on :
You are welcome! I got a lot of inspiration when I visited local astronomy clubs and observatories. I even entered a competition once (I must have been about 17) and won a telescope!
Some talented people use their inspiration for what is now called “astrophotography” to take marvellous images of the night sky. Do you know “astronomy picture of the day”? You will find fantastic astronomical images here.
Adrien commented on :
Interestingly, all we know from stars is from indirect sources (since we never went into one).
It is thus a type of guess work, using signal that you can collect from different detectors, and trying to make sense of them. Like collecting pieces of a puzzle, but not knowing what the final image should look like.
Jesse commented on :
I’ve always been very impressed by astronomers in this regard, they’ve been able to work out an incredible amount with very little to go on, compared to earth-based experiments. In the same was as metal glows red, then white hot as you heat it, stars glow different colours depending on what temperature they are. You can also work out what they’re made of by looking more closely at the light from them – each element has distinct colours that they absorb, so if you look at the light from the star, and then note which colours are missing from the light, you can tell what’s been absorbed, and therefore what the star is made of