Epsilon Chamaeleontis
Epsilon Chamaeleontis, Latinized from ε Chamaeleontis, is a naked-eye star located in the constellation Chamaeleon and is known as the star HIP 58484, HR 4583, or HD 104174, which during February 1836 Sir John Herschel found as the close double star, HJ 4486AB. Distance is 111±4 pc (362±14 light years) from the Sun, whose absolute magnitude of −0.361 and has the combined visual magnitude of +4.88. Observations throughout the 20th Century have been slowly reducing, whose latest separation is 0.364 arcsec in position angle 211°, as determined on date 1997.0905 using CCD speckle interferometry by E.P.  Horch (1997). It is a likely binary system, though no formal orbit has yet been determined. Epsilon Chamaeleontis A or HJ 4486A is an B9Vn dwarf star with an effective temperature of 11000 Kelvin. Apparent visual magnitude of +5.3, and has a mass of 3.3 solar masses. Epsilon Chamaeleontis B or HJ 4486B is also a dwarf star of undetermined 'A' spectral type with an effective temperature of about 9600 Kelvin, being based on the lesser apparent visual magnitude of +6.1, and is about 3.0 solar masses. Observation of the spectrum show strong nebula lines, suggesting the stars are of  a young age. Both stars are members of Scorpius-Centaurus Association or the smaller portion known as the Lower Centaurus Crux subgroup. The double star forms the nucleus of the very young Epsilon Chamaeleontis stellar group which comprises about twenty stars. The nebulosity and star formation occurring in this region is currently a very important line of study in the southern hemisphere, whose proximity to the Sun is yielding new astrophysical information. Several papers have been published in the last few years on Lower Centaurus Crux subgroup of stars in the far southern constellations of Musca, Chamaeleon and Octans holding  the south celestial pole.