HD 41004
HD 41004 is a visual binary star system in the southern constellation of Pictor. It is too faint to be visible to the naked eye, having a combined apparent visual magnitude of 8.65. The two components have a magnitude difference of 3.7, and share a common proper motion with an angular separation of 0.30″, as of 2018. The distance to this system is approximately 136 light years based on parallax. It is drifting further away from the Sun with a radial velocity of +42.5 km/s, having come to within 44.5 ly some 831,000 years ago.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pictor |
| Right ascension | 05h 59m 49.64736s |
| Declination | −48° 14′ 22.8058″ |
| Apparent magnitude (V) | 8.65 (8.82 + 12.51) |
| Characteristics | |
| Spectral type | K1V + M2V |
| B−V color index | 0.887±0.013 |
| Astrometry | |
| Radial velocity (Rv) | +42.5±0.5 km/s |
| Proper motion (μ) | RA: −41.520±0.485 mas/yr Dec.: +59.652±0.556 mas/yr |
| Parallax (π) | 24.0437 ± 0.2635 mas |
| Distance | 136 ± 1 ly (41.6 ± 0.5 pc) |
| Absolute magnitude (MV) | 5.60 |
| Details | |
| A | |
| Mass | 0.89±0.07 M☉ |
| Radius | 1.04+0.02 −0.03 R☉ |
| Luminosity | 0.629±0.008 L☉ |
| Surface gravity (log g) | 4.34±0.11 cgs |
| Temperature | 5,255±52 K |
| Metallicity [Fe/H] | 0.15±0.03 dex |
| Rotational velocity (v sin i) | 1.0±1.2 km/s |
| B | |
| Mass | 0.4 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary, component A, is a K-type main-sequence star with a stellar classification of K1V and a visual magnitude of 8.82. Torres et al. (2006) classed it as a K1IV star, suggesting it is a subgiant star that is evolving off the main sequence. It has 89% of the mass of the Sun and 104% of the Sun's radius. The star is radiating 63% of the Sun's luminosity from its photosphere at an effective temperature of 5,255 K. Its smaller companion, designated component B, is a red dwarf with spectral type M2V and apparent magnitude 12.33. It has a projected separation of 23 AU from the primary.