Lacaille 9352 B
Properties
This star has the fourth highest known proper motion, (which was first noticed by Benjamin Gould in 1881) moving a total of 6.9 arcseconds per year. However, this is still a very small movement overall, as there are 3,600 arcseconds in a degree of arc. The space velocity components of this star are (U, V, W) = (−93.9, −14.1, −51.4) km/s. If the radial velocity (Vr) equals +9.7 km/s then about 2,700 years ago Lacaille 9352 was at its minimal distance of approximately 10.63 ly (3.26 pc) from the Sun.
The spectrum of Lacaille 9352 places it at a stellar classification of M0.5V, indicating it is a type of main sequence star known as a red dwarf. This was the first red dwarf star to have its angular diameter measured, with the physical diameter being about 47% of the Sun's radius. It has around half the mass of the Sun and the outer envelope has an effective temperature of about 3,670 K.
Planetary system
In June 2020, two super-Earth planets were reported, as well as a third signal with a period of 50.7 days that may be due to stellar activity—however, if this planet is real it may be located within the habitable zone. They were detected using the radial velocity method from observations with HARPS in Chile and HIRES in Hawaii.
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥ 4.2±0.6 M🜨 | 0.068±0.002 | 9.262±0.001 | 0.09+0.09 −0.06 |
— | — |
c | ≥ 7.6±1.2 M🜨 | 0.120±0.004 | 21.789+0.004 −0.005 |
0.22+0.09 −0.10 |
— | — |
d (unconfirmed) | ≳ 8.3 M🜨 | ~0.21 | ~50.7 | 0.25+0.20 −0.15 |
— | — |