milky way posses 200-300 billion stars , diameter ~100-120 kly(kilo light years) ,800 solar masses AND Andromeda has 1 trillion stars ,diameter ~220 kly ,2500 solar masses, man you must go to wiki at least , and listen you cant be better than me at astronomy , i just love it . how you even dare to make me wrong regarding this question . follow the link and realize, you clicked at milky way so it dont make it bigger.
http://www.dailymail.co.uk/sciencete...rk-matter.html