# Let's make Jupiter a star

It is known that Jupiter is mostly made of hydrogen, but that it is not massive enough to start nuclear fusion. In other words, Jupiter is not a star, but could be a star if someone added hydrogen to the planet.

How can the critical mass, where there is sufficient thermal energy at the core to start nuclear fusion, be calculated?

• Related: physics.stackexchange.com/q/776 – user139561 Dec 19 '16 at 11:20
• I look forward to people's answers, but to my knowledge there isn't a good way to calculate the value from first principles. Observationally it seems to be between about $0.5-0.1 M_\odot$, with the lower end of the range (seemingly) favored more strongly as of late. – DilithiumMatrix Dec 19 '16 at 22:25