Linked from
The 7 pages that link to Solar mass, each with the reason it gives.
Stellar massBroader topic: Stellar masses are commonly reported as multiples of this reference unit.
SunRelated: The Sun’s mass sets the gravitational scale for the Solar System.
AltairRelated: Altair's mass is estimated by comparing its measured properties with stellar models.
Solar coreRelated: The Sun’s mass sets the gravitational pressure that compresses its core.
Jupiter massCompared with: It suits stellar systems whose masses are far larger than a Jupiter mass.
Astronomical system of unitsBroader topic: It served as the system’s reference unit of mass.