18 Sextantis

K-type giant star in the constellation Sextans 18 Sextantis Sextans constellation map.svg center 260 right Red circle.svg 6 18 Sextantis 508 850 Location of 18 Sex on the map (circled) J2000.0 (ICRS) Sextans 10 10 55.86074 −08 25 06.4527 5.620.01 K2/3 III +1.30 +1.42 0.22.9 5.8416 0.0881 −0.115 −43.987 −0.16 27.31.4 22212 1.72 4,410122 −0.310.01 0.00 <1.0 18 Sex 32 G. Sextantis −07°2977 13990 88333 49865 3996 137395 26206896 *18+Sex 18 Sextantis (HD 88333; HR 3996; 32 G. Sextantis), or simply 18 Sex, is a solitary star located in the southern constellation Sextans. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.62. Gaia DR3 parallax measurements imply a distance of 558 light-years and it is slowly receding with a poorly constrained heliocentric radial velocity of approximately 0.2 km/s. At its current distance, 18 Sex's brightness is diminished with an interstellar extinction of two-tenths of a magnitude and it has an absolute magnitude of −0.16. 18 Sex has a stellar classification of K2/3 III, indicating that it is an evolved star with the characteristics of a K2 and K3 giant star. At present, it has exhausted hydrogen at its core and it has expanded to 27.3 times the radius of the Sun. It radiates 222 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4410 K commas. Gaia DR3 models it to be a larger and brighter red giant branch star with a radius of 35.27 y and a luminosity of 384 y. 18 Sex is metal deficient with an iron abundance of [Fe/H] = −0.31 or 49% of the Sun's and it spins too slowly for its projected rotational velocity to be measured accurately, having a velocity lower than 1.0 km/s. See also 17 Sextantis, an A-type main-sequence star located 12' away. References 3771960229193854080 Høg E. Fabricius C. 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