Rho Serpentis, Latinized from ρ Serpentis, is a single star in the Caput section of the

equatorial Equatorial may refer to something related to: *Earth's equator **the tropics, the Earth's equatorial region **tropical climate *the Celestial equator ** equatorial orbit **equatorial coordinate system ** equatorial mount, of telescopes * equatorial ...

Serpens Serpens ( grc, , , the Serpent) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International ...

constellation. It has an orange hue and is faintly 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 +4.78. The distance to this star is approximately 375

light years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

based on parallax, but it is drifting closer to the Sun with a radial velocity of −62 km/s. This is an aging giant star with a stellar classification of K4.5III. It is a suspected

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

of unknown type, with an I-band brightness ranging from 3.29 down to 3.44 magnitude. Hipparcos photometry revealed a microvariability with a frequency of 0.17017 cycles per day and an amplitude of 0.0080. With the supply of hydrogen exhausted at its

core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

, it has expanded and now has 48 times the Sun's girth. The star is radiating 492 times the

luminosity of the Sun 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 swollen photosphere at an effective temperature of 3,930 K.

References

{{DEFAULTSORT:Rho Serpentis K-type giants Suspected variables Serpens Serpentis, Rho Durchmusterung objects Serpentis, 38 141992 077661 5899