Solar Mass (M☉)

AstronomicalCurrent unitApproximate value

About 1.988×10³⁰ kg, the mass of the Sun (roughly 332,946 Earths). Used for stars and galaxies.

1 solar mass = 1.98847×10³⁰ kilograms (approximately).

Approximate value. Standards for the solar mass varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About the solar mass

The solar mass is the mass of the Sun used as the standard weight for stars, black holes and galaxies. The best estimate is about 1.98847 x 10^30 kg, with an uncertainty near 0.005 percent, while the International Astronomical Union's nominal value is 1.988416 x 10^30 kg. That is about 332,946 Earth masses, commonly rounded to 333,000.

Isaac Newton made the first known estimate in the Principia of 1687, putting the Earth to Sun mass ratio at about 1 to 28,700. In the third edition he revised this to 1 to 169,282 after finding that his solar parallax was faulty. Transits of Venus in 1761 and 1769 later improved the Sun's distance, and Cavendish's 1798 measurement gave a usable value of G.

The unit predates precise values of G and the astronomical unit, and it survives because Kepler's third law lets astronomers compute the masses of planets and binary stars directly from orbital data in solar units. The product GM of the Sun is known far better than the mass itself.

Sources: Wikipedia: Solar mass

Solar Mass conversion chart

1 solar mass expressed in every other weight & mass unit:

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