The Mass of Bottom Quark is approx. 4.18 GeV/c2 which is bit more than 4 times the mass of Proton.
Introduction to Neutron Star: https://onheaven.co.in/…/06/introduction-to-neutron-star/
Reference Source:
[1] Wikipedia Contributors. “Bottom Quark.” Wikipedia, Wikimedia Foundation, 29 Mar. 2021, en.wikipedia.org/wiki/Bottom_quark. Accessed 7 Apr. 2021.