NGTS-3
Binary star in the constellation Columba
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NGTS-3 is a star system located in the southern constellation Columba. With an apparent magnitude of 14.67, it requires a powerful telescope to observe. However, NGTS-3 is actually an unresolved spectroscopic binary system. The system is located approximately 2,480 light years away, based on parallax measurement, and is receding with a radial velocity of 8.57 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Columba[1] |
| Right ascension | 06h 17m 46.75s[2] |
| Declination | −35° 42′ 23.05″[2] |
| Apparent magnitude (V) | 14.67±0.01[3] |
| Characteristics | |
| Evolutionary stage | main sequence + main sequence[4] |
| Spectral type | G6 V + K1 V[4] |
| B−V color index | +0.77[3] |
| R−I color index | +0.36[3] |
| Astrometry | |
| Radial velocity (Rv) | 8.57±0.05[4] km/s |
| Proper motion (μ) | RA: -8.838[2] mas/yr Dec.: +8.771[2] mas/yr |
| Parallax (π) | 1.3153±0.0193 mas[2] |
| Distance | 2,480 ± 40 ly (760 ± 10 pc) |
| Details[4] | |
| A | |
| Mass | 1.02±0.09 M☉ |
| Radius | 0.93±0.23 R☉ |
| Luminosity | 0.72±0.03[2] L☉ |
| Surface gravity (log g) | 4.45[5] cgs |
| Temperature | 5,600±150 K |
| Metallicity [Fe/H] | 0.12±0.15 dex |
| Rotational velocity (v sin i) | 1.0±0.7 km/s |
| Other designations | |
| Gaia DR2 2885350546895266432 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The system consists of two main sequence stars, classified as G6 and K1, respectively; however, only the properties of the primary star are known. NGTS-3A has a similar mass to that of the Sun, but is 7% smaller in radius. It radiates at 72% of the Sun's luminosity from its photosphere at an effective temperature of 5,600 K, which gives it the typical yellow hue characteristic of a G-type star.
Planetary System
In 2018, the NGTS survey discovered an inflated hot Jupiter orbiting NGTS-3A despite the components being visually unresolved.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.38 ± 0.26 MJ | 0.023+0.007 −0.005 |
1.6753728 ± 0.0000030 | 0? | 89.56+0.31 −0.48° |
1.48 ± 0.37 RJ |