Rho Lupi, Latinized from ρ Lupi, is a solitary star in the southern constellation of Lupus. It is visible to the naked eye with an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of 4.05. Based upon an annual parallax shift of 10.32 mas as seen from Earth, it is located about 316 light years from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. It is a member of the Upper Centaurus–Lupus subgroup of the nearby Scorpius–Centaurus association. This is a

B-type main sequence star A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars ...

with a stellar classification of B3/4 V. It is a

microvariable This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outsi ...

with a period of 10.7 hours and an amplitude of 0.0046 in magnitude. With an age of just 44 million years, the star is spinning with a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulg ...

of 166 km/s. This is giving the star an oblate shape with an

equatorial bulge An equatorial bulge is a difference between the equatorial and polar diameters of a planet, due to the centrifugal force exerted by the rotation about the body's axis. A rotating body tends to form an oblate spheroid rather than a sphere. On E ...

that is an estimated 6% larger than the polar radius. It has an estimated 4.66 times the mass of the Sun and about 3.4 times the Sun's radius. It is radiating 365 times the

solar luminosity The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...

from its outer atmosphere at an effective temperature of 15,947 K.

References

{{Stars of Lupus, state=collapsed B-type main-sequence stars Slowly pulsating B-type stars Lupus (constellation) Lupi, Rho Durchmusterung objects 071536 5453 128345 Upper Centaurus Lupus