NGTS-3

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.

NGTS-3

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
Spectral type	G6 V + K1 V
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]

The NGTS-3A planetary system^[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