Minimum mass

"M sin i" redirects here. For other uses, see [[:M sin i (disambiguation)]].

In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars and binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets. Because most extrasolar planets are currently detected by the radial velocity method, which reveals planets by measuring changes in the movement of stars in the line-of-sight, the real orbital inclinations and true masses of the planets are generally unknown.

If inclination can be determined, the true mass can be obtained from the calculated minimum mass using the following relationship:

$M_{\text{true}}={\frac {M_{\min }}{\sin i}}\,$

For orbiting bodies in extrasolar stellar and planetary systems, an inclination of 0° or 180° corresponds to a face-on orbit, while an inclination of 90° corresponds to an edge-on orbit.

References

• Kuchner, Marc J. (09-2004). "A Minimum-Mass Extrasolar Nebula". The American Astronomical Society. 612 (2): 1147–1151. Bibcode:2004ApJ...612.1147K. doi:10.1086/422577. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
• "The minimum mass ratio of W UMa-type binary systems". Monthly Notes of the Royal Astronomical Society. 377 (4): 1635–1637. June 2007. Bibcode:2007MNRAS.377.1635A. doi:10.1111/j.1365-2966.2007.11723.x. Retrieved 2008-05-24. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)