solar mass
The solar mass is about 1.98841 × 10³⁰ kilograms, roughly 333,000 Earth masses. The value here comes from dividing the IAU nominal solar mass parameter, GM = 1.3271244 × 10²⁰ m³/s², by the CODATA gravitational constant. It is the standard yardstick for every star, black hole and galaxy mass in the literature.
Watch out: Like the Earth mass, it is far less precisely known in kilograms than it is as a gravitational parameter, because G is the worst-measured of the fundamental constants. This is why the IAU defines a NOMINAL solar mass parameter as an exact conventional value and asks that stellar masses be quoted as ratios to it rather than converted to kilograms. The sun also genuinely loses mass, a few million tonnes a second to fusion and the solar wind, though that is negligible on any human timescale.
| 1 Msun | 1.9884100e+30 kg |