NGTS-6
Star with a short-period planet in Caelum
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NGTS-6 is a star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 14.12,[3] making it readily visible in telescopes with an aperture of at least 203 millimeters; it can also be viewed in telescopes with an aperture between 152 and 203 mm, albeit faintly. The star is located relatively far at a distance of 1,002 light years based on parallax measurements from the Gaia spacecraft,[2] but it is drifting closer with a heliocentric radial velocity of −19.14 km/s.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Caelum[1] |
| Right ascension | 05h 03m 10.90284s[2] |
| Declination | −30° 23′ 57.7189″[2] |
| Apparent magnitude (V) | 14.12±0.03[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | K[4] |
| Astrometry | |
| Radial velocity (Rv) | −19.14±0.01[4] km/s |
| Proper motion (μ) | RA: −9.308 mas/yr[2] Dec.: −22.014 mas/yr[2] |
| Parallax (π) | 3.2536±0.0126 mas[2] |
| Distance | 1,002 ± 4 ly (307 ± 1 pc) |
| Details[4] | |
| Mass | 0.767±0.025 M☉ |
| Radius | 0.754±0.013 R☉ |
| Luminosity | 0.256±0.009 L☉ |
| Surface gravity (log g) | 4.7+1.1 −0.7 cgs |
| Temperature | 4,730+44 −40 K |
| Metallicity [Fe/H] | 0.11±0.09 dex |
| Rotational velocity (v sin i) | 2.85±0.43 km/s |
| Age | 9.77+0.25 −0.54 Gyr |
| Other designations | |
| NGTS-6, TOI-448, TIC 1528696, 2MASS J05031090-3023576 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
NGTS-6 is a K-type main sequence star that has 76.7% the mass of the Sun and 75.4% of the Sun's radius.[4] However, it only radiates 25.6% of the Sun's luminosity[4] from its photosphere at an effective temperature of 4,730 K,[4] giving it an orange hue when viewed in a telescope. It is metal enriched with of the Sun's abundance of iron.[4] Such stars are more likely to form giant planets. NGTS-6 is estimated to be 9.77 billion years old and it spins modestly with a projected rotational velocity of 2.85 km/s.[4]
Planetary system
In 2018, a ultra-hot Jupiter was discovered orbiting the star based on transit data from the Next Generation Transit Survey. It was confirmed a year later based on doppler spectroscopy data from CORALIE and FEROS. NGTS-6b orbits extremely closely to its host star within a 21.17 hour period, making it an ultra-short period planet. The planet is 33.9% more massive than Jupiter, but it is 32.6% larger as a result of tidal heating from its close proximity.[4] The system was included in a 2024 survey as a potential target for studying the orbital decay of exoplanets.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (hours) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| NGTS-6b | 1.339±0.028 MJ | 0.01677±0.00032 | 21.169404±0.00000792 | 0.00 (fixed) | 78.231+0.262 −0.210° |
1.326+0.097 −0.112 RJ |