Qatar-4
Star in the constellation Andromeda
From Wikipedia, the free encyclopedia
Qatar-4 is a faint K-dwarf star that hosts a planet in the constellation Andromeda. With an apparent magnitude of 13.60, it is impossible to detect with the naked eye, but can be detected with a powerful telescope. Qatar-4 is currently located 1,083 light years away based on parallax.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda[1] |
| Right ascension | 00h 19m 26.22s[2] |
| Declination | +44° 01′ 39.5″[2] |
| Apparent magnitude (V) | 13.60[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | K1V[3] |
| Variable type | planetary transit |
| Astrometry | |
| Proper motion (μ) | RA: 0.923±0.011 mas/yr[2] Dec.: −8.921±0.009 mas/yr[2] |
| Parallax (π) | 3.0567±0.0158 mas[2] |
| Distance | 1,067 ± 6 ly (327 ± 2 pc) |
| Details | |
| Mass | 0.856+0.029 −0.030[4] M☉ |
| Radius | 0.800+0.015 −0.014[4] R☉ |
| Luminosity | 0.481[3] L☉ |
| Surface gravity (log g) | 4.565+0.018 −0.020[4] cgs |
| Temperature | 5174+33 −35[4] K |
| Metallicity [Fe/H] | 0.095+0.076 −0.088[4] dex |
| Rotational velocity (v sin i) | 7.1±0.5[3] km/s |
| Age | 170±0.1[3] Myr |
| Other designations | |
| Gaia DR3 385697172809355392, Qatar 4, UCAC3 269-3518 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Properties
This star is a relatively young star with an age of only 170 million years. At this age, it is still on the main sequence. Qatar-4 has 89.6% the mass of the Sun, and 84.9% the latter's radius. Despite all of this, it only has 48.1% of the Sun's luminosity, which corresponds to an effective temperature of 5,120 K. Qatar-4 has a similar metallicity to the Sun, and rotates at a rate of 7.1 km/s.
Planetary system
In 2016, the Qatar Exoplanet Survey discovered a planet around this star.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 5.26+0.22 −0.21 MJ |
0.02861 | 1.80536494±9−7 | 0.046+0.064 −0.034 |
87.5±1.6° | 1.083+0.022 −0.021 RJ |
| Discovery[3] | |
|---|---|
| Discovered by | Alsubai et al. 2019 |
| Transit | |
| Orbital characteristics | |
| 0.02803 ± 0.00048 au[3] | |
| Eccentricity | 0[3] |
| 1.8053564 d[3] | |
| Inclination | 87.5 ± 1.6°[3] |
| Semi-amplitude | 957±16 m/s[3] |
| Physical characteristics | |
| 1.135 ± 0.11 RJ[3] | |
| Mass | 5.36 ± 0.20 MJ[3] |
Mean density | 4.50 ± 1.00 g cm−3[3] |
| Temperature | 1385 ± 50 K[3] |
Qatar-4b
Qatar-4b is a Super-Jupiter orbiting the star Qatar-4 every 1.8 days. It was discovered in 2016 by the Qatar Exoplanet Survey (QES).
This planet has a very short orbit, with only 1.8 days for it to complete an orbit around Qatar-4. The period corresponds with a separation of around 0.03 AU, which is almost 20 times closer than Mercury is to the Sun. Despite that, it has a perfectly round orbit. Since the host is an active star, Qatar-4 may be destroyed by tidal waves from the star.[5]
Qatar-4b has over 5 times the mass of Jupiter. Despite this, it has a radius that is only 13.5% larger than the latter's. This planet has an effective temperature of 1,385 K, which classifies as a hot Jupiter, and is denser than Jupiter, with about 4 times the density.