( ( If ( it ( has ( the ( right mass ) ) ) ) ) ( it ( ( becomes ( a ( white ( dwarf star ) ) ) ) . ) ) )
(ROOT (S (SBAR (IN If) (S (NP (PRP it)) (VP (VBZ has) (NP (DT the) (JJ right) (NN mass))))) (NP (PRP it)) (VP (VBZ becomes) (NP (DT a) (JJ white) (NN dwarf) (NN star))) (. .)))
If it has the right mass it becomes a white dwarf star.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT the) (NNP helium)) (VP (VBZ is) (VP (VBN gone))))) (, ,) (NP (DT the) (NNS stars)) (VP (VBP become) (NP (JJ white) (NNS dwarfs))) (. .)))