Lambda Chamaeleontis
Lambda Chamaeleontis, Latinized from λ Chamaeleontis, is a star located in the constellation Musca. Lambda Chamaeleontis is also known as HR 4617, and HD 105340. This star is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.165. It is located 472 light-years (145 parsecs) from the Sun, based on its parallax, but is drifting closer with a radial velocity of −45 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Musca |
| Right ascension | 12h 07m 49.87515s |
| Declination | −75° 22′ 01.2583″ |
| Apparent magnitude (V) | 5.165 |
| Characteristics | |
| Spectral type | K2II/III |
| U−B color index | +1.37 |
| B−V color index | +1.30 |
| Astrometry | |
| Radial velocity (Rv) | −45.30±0.8 km/s |
| Proper motion (μ) | RA: −92.465 mas/yr Dec.: +18.898 mas/yr |
| Parallax (π) | 6.9109 ± 0.0916 mas |
| Distance | 472 ± 6 ly (145 ± 2 pc) |
| Absolute magnitude (MV) | −0.40 |
| Details | |
| Radius | 30.21+1.30 −4.03 R☉ |
| Luminosity | 286.8+4.7 −13.3 L☉ |
| Temperature | 4322+320 −90 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging K-type giant/bright giant with a stellar classification of K2II/III. With the supply of hydrogen at its core exhausted, the star expanded and cooled. It now has 30 times the radius of the Sun and is radiating 287 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,322 K.
The star was first designated Lambda Chamaeleontis by French astronomer Lacaille, in his Coelum Australe Stelliferum. He listed it close to Pi Chamaeleontis in both brightness and location. The IAU redefinition of the constellation borders in 1930, has placed Lambda Chamaeleontis slightly over the border in Musca, rather than Chamaeleon.