Hey. Tried searching for this but was unsuccessful.
Now, to preface this, I know absolutely nothing about science. I’ve watched a few documentaries, but that’s as far as my knowledge goes.
I have been wondering about something for a while but whenever I try looking it up, the answers are far too complex for me to understand.
So my question revolves around stars. First, how is distance to stars measured? How do we know that it is reasonably accurate, and not a situation where said star was smaller and closer or bigger and farther away than previously thought?
Second, how is the brightness measured? I’ve heard stuff like “this and that star shines 100x brighter than our sun”. How can that be reasonably accurately measured over the vast distances we’re talking about in space?
Third, how can we measure or calculate mass of a star, given the vast distances?
I suspect those 3 questions might be somewhat linked, so I thought I’d ask all 3 in the same thread.
Now keep in mind, I do not understand calculus or math above algebra, so if anything like that is needed to understand, please dumb it down as much as you reasonably can.
Thankful for any replies helping me wrap my head around these concepts. Thanks in advace!
In: 9
We can calculate the distance to a star by measuring how much it shifts its position in the sky half a year apart. In that time Earth moves from one side of its orbit around the Sun to the opposite side, and that is far enough that stars change their positions noticeably provided you can make precise measurements. Knowing the distance and the visible brightness of a star you can calculate its absolute brightness. Determining mass is less straightforward and involves measuring the speed of motion of stars in binary systems around each other, estimating from correlations from brightness and spectrum, observing gravitational lensing of light etc.
Latest Answers