Here's why:
* Main Sequence Lifetime: The main sequence is the longest and most stable phase of a star's life. During this period, the star fuses hydrogen into helium in its core. The longer a star can sustain this fusion process, the longer its main sequence lifetime.
* Stellar Mass and Lifetime: A star's mass is the primary factor determining its main sequence lifetime. More massive stars have higher core temperatures and pressures, leading to faster fusion rates. This causes them to burn through their hydrogen fuel much faster, resulting in shorter main sequence lifetimes.
* Relationship: There's a general inverse relationship between a star's mass and its main sequence lifetime. The exact relationship is complex, but a rule of thumb is that a star's lifetime is roughly proportional to the inverse cube of its mass:
* Lifetime ∝ 1/Mass³
Important Note: While a 2 solar mass star has a main sequence lifetime of roughly 10 billion years, it's essential to remember that this is an approximation. There are other factors, like the star's initial chemical composition, that can slightly affect its lifespan.
