TZ Fornacis
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Fornax |
| Right ascension | 03h 14m 40.093s |
| Declination | −35° 33′ 27.59″ |
| Apparent magnitude (V) | 6.88 (7.51 + 7.76) |
| Characteristics | |
| Evolutionary stage | Giant + subgiant |
| Spectral type | G8 III + F7 III |
| B−V color index | 0.740±0.006 |
| Variable type | Algol |
| Astrometry | |
| Radial velocity (Rv) | 18.0±2.4 km/s |
| Proper motion (μ) | RA: 34.598 mas/yr Dec.: 17.389 mas/yr |
| Parallax (π) | 5.4708±0.0193 mas |
| Distance | 596 ± 2 ly (182.8 ± 0.6 pc) |
| Absolute magnitude (MV) | 0.70 |
| Orbit | |
| Primary | A |
| Companion | B |
| Period (P) | 75.66647±0.00006 d |
| Semi-major axis (a) | 2.993±0.030 mas 0.5564±0.0001 AU |
| Eccentricity (e) | 0.00002±0.00003 |
| Inclination (i) | 85.68±0.05° |
| Longitude of the node (Ω) | 65.99±0.03° |
| Argument of periastron (ω) (secondary) | 269.93±0.04° |
| Semi-amplitude (K1) (primary) | 38.90±0.01 km/s |
| Semi-amplitude (K2) (secondary) | 40.87±0.02 km/s |
| Details | |
| A | |
| Mass | 2.057±0.001 M☉ |
| Radius | 8.28±0.22 R☉ |
| Luminosity | 37.2+1.8 −1.7 L☉ |
| Surface gravity (log g) | 2.91±0.02 cgs |
| Temperature | 4,930±30 K |
| Metallicity [Fe/H] | 0.02±0.05 dex |
| Rotational velocity (v sin i) | 6.1±0.3 km/s |
| Age | 1.20±0.10 Gyr |
| B | |
| Mass | 1.958±0.001 M☉ |
| Radius | 3.94±0.17 R☉ |
| Luminosity | 22.9+1.5 −1.6 L☉ |
| Surface gravity (log g) | 3.35±0.02 cgs |
| Temperature | 6,650±200 K |
| Metallicity [Fe/H] | −0.05±0.10 dex |
| Rotational velocity (v sin i) | 45.7±1.0 km/s |
| Other designations | |
| CD−36° 1218, FK5 1090, GC 3886, HD 20301, HIP 15092, SAO 194176, PPM 278845 | |
| Database references | |
| SIMBAD | data |
TZ Fornacis is an eclipsing binary star system in the southern constellation of Fornax. It has the designation HD 20301 from the Henry Draper Catalogue; TZ Fornacis is the variable star designation, abbreviated TZ For. This target is a challenge to view with the naked eye, having a peak apparent visual magnitude of 6.88. During an eclipse, the magnitude drops to 7.05. This system is located at a distance of approximately 596 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of roughly 18 km/s.