Qatar-8

Last updated
Qatar-8
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Ursa Major
Right ascension 10h 29m 39.11s [1]
Declination +70° 31′ 37.7″ [1]
Apparent magnitude  (V)11.71±0.12 [2]
Characteristics
Evolutionary stage main-sequence star [3]
Spectral type G0V [3]
Variable type planetary transit
Astrometry
Radial velocity (Rv)5.06±0.32 [1]  km/s
Proper motion (μ)RA: −46.527±0.050  mas/yr [1]
Dec.: −9.597±0.047  mas/yr [1]
Parallax (π)3.528 ± 0.0321  mas [1]
Distance 924 ± 8  ly
(283 ± 3  pc)
Details [3]
Mass 1.029  M☉
Radius 1.315  R☉
Luminosity 1.69  L☉
Surface gravity (log g)4.214  cgs
Temperature 5,738  K
Metallicity [Fe/H]0.025  dex
Rotational velocity (v sin i)2.7 km/s
Age 8.3±2.1  Gyr
Other designations
2MASS J10293910+7031378, Gaia DR2 1076515002779544960
Database references
SIMBAD data
Exoplanet Archive data
Extrasolar Planets
Encyclopaedia 		data

Qatar-8 is a faint solar analog located in the northern circumpolar constellation Ursa Major. With an apparent magnitude of 11.71, it is impossible to detect with the naked eye, but can be located with a powerful telescope. Qatar-8 is currently 924 light-years (283 parsecs ) away from the Solar System, but is drifting further away, with a radial velocity of 5.06 km/s.

Contents

Properties

Qatar-8 is a relatively old star, with an age of 8.3 billion years. At this rate, it is on the final stages of the main sequence. It has a similar effective temperature to the Sun at 5,738 K. Despite that, it has a 69% greater luminosity than the Sun. Qatar-8 has a radius 31.5% greater than the Sun, and has a similar metallicity to the Sun despite its age.

Planetary system

In 2019, the Qatar Exoplanet Survey (QES) discovered planets around Qatar-9, itself, and Qatar-10. However, Qatar-8b is a puffy Hot Saturn unlike the other planets discovered. [3]

The Qatar-8 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 0.371  MJ 0.04743.719089.29° 1.285  RJ

Since Qatar-8b is a puffy planet, it only has 37.1% the mass of Jupiter. Due to that, it puffs up to a radius that is 28.5% larger than the latter's. It also has an effective temperature of 1,457 K. Qatar-8b is ten times closer to its star than Mercury is to the Sun, which corresponds to a typical four-day orbit. [3]

Qatar-8b
Discovery
Discovery date2019
Transit
Orbital characteristics [3]
0.0474 AU
Eccentricity 0
3.714 days
Semi-amplitude 47.7 ± 8.0 ms -1
Physical characteristics
Mean radius
1.285 RJ [3]
Mass 0.371 MJ [3]
Mean density
0.216 g cm−3 [3]


    Companion

    Qatar-8 was suspected to have a stellar companion, which makes it a binary star. However, a study in 2020 after analysis of many other stars show no stellar companion at all. [4]

    Related Research Articles

    <span class="mw-page-title-main">Hot Jupiter</span> Class of high mass planets orbiting close to a star

    Hot Jupiters are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods. The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters".

    WASP-8 is a binary star system of 9.9 magnitude. The star system is much younger than the Sun at 300 million to 1.2 billion years age, and is heavily enriched in heavy elements, having nearly twice the concentration of iron compared to the Sun.

    WASP-12 is a magnitude 11 yellow dwarf star located approximately 1410 light-years away in the constellation Auriga. WASP-12 has a mass and radius similar to the Sun and is known for being orbited by a planet that is extremely hot and has a retrograde orbit around WASP-12. WASP-12 forms a triple star system with two red dwarf companions. Both of them have spectral types of M3V and are only 38% and 37% as massive as the Sun, respectively.

    HAT-P-8 is a magnitude 10 star located 700 light-years away in Pegasus. It is a F-type star about 28% more massive than the Sun. Two red dwarf companions have been detected around HAT-P-8. The first has a spectral type of M5V and has a mass of 0.22 M☉. The second is even less massive, at 0.18 M☉, and its spectral type is M6V.

    HD 215497 is a single star in the southern constellation of Tucana. It has an orange hue with an apparent visual magnitude of 8.96, which is too dim to be viewed with the naked eye. A 2015 survey ruled out the existence of any stellar companions at projected distances from 26 to 300 astronomical units. Based on parallax measurements, it is located at a distance of 132 light years from the Sun. The star is drifting further away with a radial velocity of +49 km/s, having come as close as 45 light-years some 774,000 years ago. The absolute magnitude of this star is 5.77.

    <span class="mw-page-title-main">V1400 Centauri</span> Sun-like star in the constellation Centaurus

    V1400 Centauri is a pre-main-sequence star in the constellation Centaurus at a distance of about 451 light-years from Earth. A relatively young star, its age is estimated to be 16 million years, and its mass is about 90% that of the Sun. The star has a maximum apparent magnitude of 12.2 and requires a telescope to be seen. The star's name comes from the SuperWASP program and the star's coordinates.

    KELT-18b is a hot Jupiter orbiting the F-type main sequence star KELT-18 approximately 1,058 light years away in the northern circumpolar constellation Ursa Major. The planet was discovered using the transit method, and was announced in June 2017.

    WASP-76, also known as BD+01 316, is a yellow-white main sequence star in the constellation of Pisces. Since 2014, it has had one suspected stellar companion at a projected separation of 85 astronomical units.

    HD 146389, is a star with a yellow-white hue in the northern constellation of Hercules. The star was given the formal name Irena by the International Astronomical Union in January 2020. It is invisible to the naked eye with an apparent visual magnitude of 9.4 The star is located at a distance of approximately 446 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −9 km/s. The star is known to host one exoplanet, designated WASP-38b or formally named 'Iztok'.

    HD 233731, or HAT-P-22, is a suspected multiple star system in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye, having an apparent visual magnitude of 9.732. This system is located at a distance of 267 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +13 km/s.

    Qatar-2 is a K-type main-sequence star about 595 light-years away. The star is much older than Sun, and has a concentration of heavy elements similar to solar abundance. The star features a numerous and long-lived starspots, and belongs to a peculiar variety of inflated K-dwarfs with strong magnetic activity inhibiting internal convection.

    WASP-63 or Kosjenka, also known as CD-38 2551, is a single star with an exoplanetary companion in the southern constellation of Columba. It is too faint to be visible with the naked eye, having an apparent visual magnitude of 11.1. The distance to this system is approximately 942 light-years based on parallax measurements, but it is drifting closer with a radial velocity of −24 km/s.

    WASP-58 is a binary star system comprising a G-type main-sequence star and a red dwarf about 955 light-years away. WASP-58 is slightly depleted in heavy elements, having 80% of the solar abundance of iron. WASP-58 is much older than the Sun at 12.80+0.20
    −2.10     billion years.

    KELT-1 is a F-type main-sequence star. Its surface temperature is 6518±50 K. It is similar to the Sun in its concentration of heavy elements, with a metallicity Fe/H index of 0.008±0.073, but is much younger at an age of 1.75±0.25 billion years. The star is rotating very rapidly.

    WASP-84, also known as BD+02 2056, is a G-type main-sequence star 327 light-years away in the constellation Hydra. Its surface temperature is 5350±31 K, and is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.05±0.02. It is rich in carbon and depleted of oxygen. WASP-84's age is probably older than the Sun at 8.5+4.1
    −5.5     billion years. The star appears to have an anomalously small radius, which can be explained by the unusually high helium fraction or by it being very young.

    Qatar-3 is a 12th magnitude star located in the northern constellation Andromeda. It is host to a transiting planet. With a radial velocity of 10.99 km/s, it is drifting away from the Solar System, and is currently located 2,400 light years away based on its annual parallax.

    KELT-3 is a star in the zodiac constellation Leo. With an apparent magnitude of 9.82, it is too faint to be seen with the naked eye, but can be detected using a telescope. It is currently located around 690 light years away, based on parallax measurements.

    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.

    CD−34°8618, also known as KELT-13 or WASP-167, is a yellowish-white hued star located in the southern constellation of Centaurus. It has an apparent magnitude of 10.52, making it readily visible in medium sized telescopes, but not to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be approximately 1,350 light years away from the Solar System. It appears to be drifting closer to it, having a radial velocity of −0.53 km/s.

    KELT-24, also known as MASCARA-3, is a star in the constellation of Ursa Major.

    References

    1. 1 2 3 4 5 6 Gaia Collaboration (2018-04-01). "VizieR Online Data Catalog: Gaia DR2 (Gaia Collaboration, 2018)". VizieR Online Data Catalog. 1345. Bibcode:2018yCat.1345....0G.
    2. ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000-03-01). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN   0004-6361.
    3. 1 2 3 4 5 6 7 8 9 Alsubai, Khalid; Tsvetanov, Zlatan I.; Pyrzas, Stylianos; Latham, David W.; Bieryla, Allyson; Eastman, Jason; Mislis, Dimitris; Esquerdo, Gilbert A.; Southworth, John; Mancini, Luigi; Esamdin, Ali (2019-06-01). "Qatar Exoplanet Survey: Qatar-8b, 9b, and 10b---A Hot Saturn and Two Hot Jupiters". The Astronomical Journal. 157 (6): 224. arXiv: 1903.09258 . Bibcode:2019AJ....157..224A. doi:10.3847/1538-3881/ab19bc. ISSN   0004-6256. S2CID   85459500.
    4. ↑ Maciejewski, G. (2020-09-01). "Search for Planets in Hot Jupiter Systems with Multi-Sector TESS Photometry. I. No Companions in Planetary Systems KELT-18, KELT-23, KELT-24, Qatar-8, WASP-62, WASP-100, WASP-119, and WASP-126". Acta Astronomica. 70 (3): 181–202. arXiv: 2010.11977 . Bibcode:2020AcA....70..181M. doi:10.32023/0001-5237/70.3.2. ISSN   0001-5237. S2CID   225061977.
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