Our Sun is already an adult star! It took about 50 million years to reach the main sequence, the stage where it burns hydrogen into helium in its core, which is what we consider adulthood for a star.

Here's a breakdown of the stages:

* Protostar: This is the initial phase where the star is forming from a cloud of gas and dust. This phase can last for tens of thousands to millions of years.

* T Tauri phase: This is a pre-main sequence stage where the star is still contracting and heating up. This phase can last for a few million years.

* Main sequence: This is the stable stage where the star is burning hydrogen in its core. For a star like our Sun, this stage lasts for about 10 billion years.

So, while our Sun took about 50 million years to reach adulthood, it will continue to burn hydrogen for another 5 billion years before it enters its red giant phase.