| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 14m 10.4660s [2] |
| Declination | −32° 47′ 34.496″ [2] |
| Apparent magnitude (V) | 10.68 [3] |
| Characteristics | |
| Spectral type | K5Ve / K7Ve [4] |
| Variable type | T Tauri [4] |
| Astrometry | |
| Radial velocity (Rv) | −6.94 [4] km/s |
| Distance | 271 ly (83 [4] pc) |
| Orbit [4] | |
| Period (P) | 2.4213305(40) d |
| Semi-major axis (a) | 9.24 R☉ |
| Eccentricity (e) | ≤0.01 |
| Inclination (i) | 35° |
| Periastron epoch (T) | JD 2452380.867 ± 0.03 |
| Details | |
| Mass | 0.912 / 0.873 [4] M☉ |
| Surface gravity (log g) | 4.0 / 4.0 [4] cgs |
| Temperature | 4370 / 4100 [4] K |
| Rotational velocity (v sin i) | 14.2 / 13.7 [4] km/s |
| Age | ~12 [5] Myr |
| Other designations | |
| HD 319139, CD −32° 13906, GSC 07396-00644 | |
| Database references | |
| SIMBAD | data |
V4046 Sagittarii is a young binary consisting of two K-type main-sequence stars. The two stars are about 271 light-years (83 parsecs) away from the Earth. [4] The two stars orbit each other every 2.42 days on a circular orbit. [4]
Contents
In 1976, Ivo C. Busko and Carlos Alberto Oliveira Torres announced that the star, then known as HD 319139, is a variable star. [6] [7] It was given its variable star designation, V4046 Sagittarii, in 1981. [8] It is both a classical T Tauri star, and a star showing periodic variability due to starspots. [9]
V4046 Sagittarii is surrounded by a massive protoplanetary disk. The disk has a radius of about 370 astronomical units (au) with about 40 Earth masses of dust in the disk. There are two bright inner rings at 14 and 25 au from the center, respectively. [10] V4046 Sagittarii is one of four pre-main-sequence star systems within 100 parsecs with protoplanetary disks, the others being TW Hydrae, HD 141569, and 49 Ceti. The two stars are still accreting matter from the disk, and gas giant planets may be forming in the disk as well. [5]
The red dwarf GSC 07396-00759 is separated about 2.82″ from V4046 Sagittarii. Since it has a similar motion throughout space with V4046 Sagittarii, GSC 07396-00759 is assumed to be gravitationally bound (although weakly) to V4046 Sagittarii. The two systems are separated by at least 12,350 astronomical units (0.1953 ly) away, and the orbital period would be on the order of 100,000 years. [12] GSC 07396-00759 itself has an edge-on debris disk with a radius of 70 au, [13] and may be a binary as well, making V4046 Sagittarii a potentially quadruple system. [12]
