Astronomy:Qatar-4

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Short description: Star in the constellation Andromeda
Qatar-4
Observation data
Equinox J2000.0]] (ICRS)
Constellation Andromeda
Right ascension  00h 19m 26.22s[1]
Declination +44° 01′ 39.48″[1]
Apparent magnitude (V) 13.60[2]
Characteristics
Evolutionary stage main sequence star
Spectral type K1V
Variable type planetary transit
Astrometry
Proper motion (μ) RA: 0.985±0.031[1] mas/yr
Dec.: −8.866±0.017[1] mas/yr
Parallax (π)3.0105 ± 0.0263[1] mas
Distance1,083 ± 9 ly
(332 ± 3 pc)
Details
Mass0.856+0.029−0.030[3] M
Radius0.800+0.015−0.014[3] R
Luminosity0.481[2] L
Surface gravity (log g)4.565+0.018−0.020[3] cgs
Temperature5174+33−35[3] K
Metallicity [Fe/H]0.095+0.076−0.088[3] dex
Rotational velocity (v sin i)7.1±0.5[2] km/s
Age170±0.1[2] Myr
Other designations
Gaia DR2 385697172809355392, Qatar 4, UCAC3 269-3518
Database references
SIMBADdata
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia
data

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.

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.

The Qatar-4 planetary system[3]
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
Qatar-4b
Discovery[2]
Discovered byAlsubai et al. 2019
Transit
Orbital characteristics
0.02803 ± 0.00048 au[2]
Eccentricity0[2]
Orbital period1.8053564 d[2]
Inclination87.5 ± 1.6°[2]
Semi-amplitude957±16 m/s[2]
Physical characteristics
Mean radius1.135 ± 0.11 RJ[2]
Mass5.36 ± 0.20 MJ[2]
Mean density4.50 ± 1.00 g cm−3[2]
Physics1385 ± 50 K[2]


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 astronomical unit|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.[4]

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.

See also

References

  1. 1.0 1.1 1.2 1.3 Gaia Collaboration (2018-04-01). "VizieR Online Data Catalog: Gaia DR2 (Gaia Collaboration, 2018)". VizieR Online Data Catalog 1345. Bibcode2018yCat.1345....0G. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 Alsubai, Khalid; Mislis, Dimitris; Tsvetanov, Zlatan I.; Latham, David W.; Bieryla, Allyson; Buchhave, Lars A.; Esquerdo, Gilbert A.; Bramich, D. M. et al. (2017-04-01). "Qatar Exoplanet Survey : Qatar-3b, Qatar-4b, and Qatar-5b". The Astronomical Journal 153 (4): 200. doi:10.3847/1538-3881/aa6340. ISSN 0004-6256. Bibcode2017AJ....153..200A. http://eprints.keele.ac.uk/3544/1/2017AJ....153..200A.pdf. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Wang, Xian-Yu; Wang, Yong-Hao; Wang, Songhu; Wu, Zhen-Yu; Rice, Malena; Zhou, Xu; Hinse, Tobias C.; Liu, Hui-Gen et al. (2021), "Transiting Exoplanet Monitoring Project (TEMP). VI. The Homogeneous Refinement of System Parameters for 39 Transiting Hot Jupiters with 127 New Light Curves", The Astrophysical Journal Supplement Series 255 (1): 15, doi:10.3847/1538-4365/ac0835, Bibcode2021ApJS..255...15W 
  4. Hamer, Jacob H.; Schlaufman, Kevin C. (2019-11-01). "Hot Jupiters Are Destroyed by Tides While Their Host Stars Are on the Main Sequence". The Astronomical Journal 158 (5): 190. doi:10.3847/1538-3881/ab3c56. ISSN 0004-6256. Bibcode2019AJ....158..190H.