( ( ( Exoplanets and ) ( multiple ( star systems ) ) ) . )
(ROOT (NP (NP (NP (NNS Exoplanets)) (CC and) (NP (JJ multiple) (NN star) (NNS systems))) (. .)))
Exoplanets and multiple star systems.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN exoplanet)) (VP (VBZ is) (ADVP (RB often)) (VP (VBN discovered) (SBAR (IN because) (S (NP (PRP it)) (VP (VBZ causes) (NP (DT a) (NN star) (S (VP (VP (TO to) (VP (VB move))) (CC or) (VP (TO to) (VP (VB dim))))))))))) (. .)))