HD 33519
HD 33519, also known as HR 1682, is a probable spectroscopic binary located in the southern circumpolar constellation Mensa. It is one of the stars near the limit of naked eye visibility, having an apparent magnitude of 6.28. The system is relatively far at a distance of 940 light years but is approaching with a heliocentric radial velocity of . However, this value is poorly constrained. The visible component has a stellar classification of K5/M0 III, indicating an evolved red giant with the characteristics of a K5 and M0 giant star. At present it has 4.34 times the mass of the Sun but has expanded to 45.4 times its girth. It shines with a luminosity of  from its enlarged photosphere at an effective temperature of , giving it an orange-red hue when viewed in the night sky. HD 33519's metallicity, what astronomers dub as elements heavier than helium, is around solar level. Like most giants, it spins slowly, with its projected rotational velocity being lower than . There is an 11th magnitude optical companion located  away along a position angle of . It has no relation to the system, having a drastically different proper motion. References

K-type giants
M-type giants
Mensa (constellation)
Spectroscopic binaries
Double stars
033519
023251
1682
CD-78 00190
Mensae, 19