What does the spectrum of white dwarf stars indicate about their age?

Question

All WD stars cluster in one area of the H-R diagram but there is no indication of the age. This is an important detail that needs to be studied and data would help if any exists.

Answer 1

white dwarfs follow a linear line on the H-R diagram as they progess from the top left to the bottom right. The farther they are on the right the less luminous they are hence they must be older because they don't have enough material and gravitational pressure to burn nuclear fuel, so they cool as the drop on the H-R diagram, so it is an age indicator

Answer 2

I am not certian of this question, i do know that a white dwarf is a star that has exeeded its life and in the process of cooling down,, in millions of years it will cool to the point that it will become a brown dwarf if I remember right,, but dont hold me to it and if it is your homework you should go do a web search for white dwarfs,, and study,,