Lacaille 9352
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Lacaille 9352 (Lac 9352) is a red dwarf star in the southern constellation of Piscis Austrinus. With an apparent visual magnitude of 7.34,<ref name="mnrassa32"/> this star is too faint to be viewed with the naked eye except possibly under excellent seeing conditions. Parallax measurements place it at a distance of about Template:Convert from Earth.<ref name=aaa474_2_653/> It is the eleventh closest star system to the Solar System<ref name=RECONS/> and is the closest star in the constellation Piscis Austrinus. Its closest neighbour is the EZ Aquarii triple star system at about 4.1 ly away.
Properties
This star has the fourth highest known proper motion,<ref name=esa20070701/> (which was first noticed by Benjamin Gould in 1881<ref name=first_noted/>) 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 Template:Nowrap = Template:Nowrap.<ref name=aricns/> 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 Template:Convert from the Sun.<ref name=simbad_notes/>
The spectrum of Lacaille 9352 places it at a stellar classification of M0.5V,<ref name="aaa505" /> 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,<ref name=glindemann_paresce/> with the physical diameter being about 47% of the Sun's radius.<ref name="Pineda2021" /> It has around half the mass of the Sun<ref name="aaa505"/> and the outer envelope has an effective temperature of about 3,670 K.<ref name="Pineda2021" />
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.<ref name="Jeffers Dreizler Barnes Haswell pp. 1477–1481" /><ref name="GJ887 Nature"/>
Additionally, the star presents a difference on proper motion measurements taken by the Hipparcos and Gaia spacecrafts, suggesting the presence of an outer giant planet.<ref name=Painter2025/>
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