( ( ( ( ( This property ) , ) ( when ( ( ( ( calibrated ( as ( ( the ( absolute magnitude ) ) ( at maximum ) ) ) ) brightness ) ( versus ( the time ) ) ) ( taken ( to ( decline ( by ( two magnitudes ) ) ) ) ) ) ) ) , ) ( ( allows ( novas ( to ( be ( used ( as ( ( distance indicators ) ( for ( nearby galaxies ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT This) (NN property)) (, ,) (SBAR (WHADVP (WRB when)) (S (NP (NP (ADJP (VBN calibrated) (PP (IN as) (NP (NP (DT the) (JJ absolute) (NN magnitude)) (PP (IN at) (NP (NN maximum)))))) (NNS brightness)) (PP (IN versus) (NP (DT the) (NN time)))) (VP (VBN taken) (S (VP (TO to) (VP (VB decline) (PP (IN by) (NP (CD two) (NNS magnitudes))))))))) (, ,)) (VP (VBZ allows) (S (NP (NNS novas)) (VP (TO to) (VP (VB be) (VP (VBN used) (PP (IN as) (NP (NP (NN distance) (NNS indicators)) (PP (IN for) (NP (JJ nearby) (NNS galaxies)))))))))) (. .)))
This property, when calibrated as the absolute magnitude at maximum brightness versus the time taken to decline by two magnitudes, allows novas to be used as distance indicators for nearby galaxies.
(ROOT (S (NP (NNP Distance)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN magnitude) (CC or) (NN size)) (PP (IN of) (NP (NP (NN displacement)) (PP (IN between) (NP (CD two) (NNS positions))))))))) (. .)))