Latin quote or phase

I would like to know a latin phase for brothers, to represent the bond. or either if some one can translate "even though you cannot always see them they are there with you", i ask this due to i am having a tattoo done and it will be of my brothers star sign constellation and i would like writting to put behind it. He lives on the other side of the world to me and i think it may be a good idea.

if anyone can help me?

thankyou