//[astronomy](../../../index.md)/[io.github.cosinekitty.astronomy](../index.md)/[StateVector](index.md)/[vz](vz.md) # vz val [vz](vz.md): [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html) A Cartesian velocity z-component expressed in AU/day.