Can someone explain relative brightness and parallax to me? (OCR 21st Century)

I've got a parallax diagram in front of me so don't worry about that...To be honest I understand parallax a bit but I just can't get my head round relative brightness. It's so confusing.

Are we talking about the physics terms?

yeah, the two methods of measuring the distance to stars.

Right... Well my understanding isn't top notch but Ill give it a go:

Parallax is just the apparent movement of a near object against a further away one - like if you stick your thumb up and close one eye at a time (the thumb looks like it's moving). The opposite sides of Earth's orbit (winter solstice and summer solstice) are like switching eyes - the closer stars appear to move in relation to the ones that further away. The true position of the star (relative to our sun) is slap-bang in the middle of the two extremes. See: (http://hyperphysics.phy-astr.gsu.edu/hbase/astro/imgast/stelpar.gif) this diagram. To find distance of said star from the sun use the formula included.

As for apparent brightness:



No clue if that helps.

It looks like apparent brightness is....well, exactly that. They look at a star and say "It looks brighter than that one so it must be closer".

There is another one which is similar to this called absolute brightness, which is basically where they figure out how much light the star actually emits - but I have no clue how that one works.

Are you sure this is GCSE stuff? We never did anything like this.

Thanks! That helps a LOT. (Didn't need the spoiler bit though lol, that looks like university level to me)
and yeah, P1 Earth in the Universe OCR 21st Century. Part of the module is about measuring the distance to stars. -_- I hate physics...

Wow...I did edexcel and the most complex thing we had to do with stars was..."What is redshift?" And yeah I love physics

red shift is eaaaasy
ha lucky! It's my worst subject XD