HAT-P-21

Last updated
HAT-P-21 / Mazalaai
Observation data
Epoch J2000       Equinox J2000
Constellation Ursa Major
Right ascension 11h 25m 05.9859s [1]
Declination +41° 01′ 40.665″ [1]
Apparent magnitude  (V)11.46 [2]
Characteristics
Spectral type G3V
Astrometry
Radial velocity (Rv)-51.98 km/s
Proper motion (μ)RA: −1.142(17)  mas/yr [1]
Dec.: 13.523(24)  mas/yr [1]
Parallax (π)3.5190 ± 0.0228  mas [1]
Distance 927 ± 6  ly
(284 ± 2  pc)
Details [3] [4]
Mass 0.947±0.042  M☉
Radius 1.105±0.083  R☉
Luminosity 1.06+0.20
−0.16  L☉
Surface gravity (log g)4.33±0.06  cgs
Temperature 5634±67  K
Metallicity 0.04±0.08
Rotation 15.88±0.02 d [5]
Rotational velocity (v sin i)3.5±0.5 km/s
Age 10.2±2.5  Gyr
Other designations
Mazalaai, Gaia DR3  770622651659107712, TYC  3013-1229-1, GSC  03013-01229, 2MASS J11250598+4101406 [2]
Database references
SIMBAD data

HAT-P-21 is a G-type main-sequence star about 927 light-years away. The star has amount of metals similar to solar abundance. The survey in 2015 has failed to detect any stellar companions. [6] The star is rotating rapidly, being spun up by the tides of giant planet on close orbit. [4]

Contents

Naming

In 2019, the HAT-P-21 star received the proper name Mazalaai while its planet HAT-P-21b received the name Bambaruush at an international NameExoWorlds contest. [7] These names refer to the Mongolian name for the endangered Gobi bear subspecies, and the Mongolian term for 'bear cub', respectively.

Planetary system

In 2010 a transiting hot super-Jovian planet on moderately eccentric orbit was detected. [8] Its equilibrium temperature is 1283±50 K. The transit-timing variation survey in 2011 have failed to rule out or confirm the existence of additional planets in the system, until the orbital parameters of HAT-P-21b are known with better precision. [5]

The planetary orbit is likely aligned with the equatorial plane of the star, misalignment equal to 25±16 degrees. [9]

Size comparison of HAT-P-21 b and Jupiter Exoplanet Comparison HAT-P-21 b.png
Size comparison of HAT-P-21 b and Jupiter
The HAT-P-21 planetary system [8] [10]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b (Bambaruush) 4.063±0.161  MJ 0.0494±0.00074.124481±0.0000070.228±0.01688.6° 1.08±0.18  RJ

Related Research Articles

<span class="mw-page-title-main">Tau Boötis</span> Star in the constellation of Boötes

Tau Boötis, Latinised from τ Boötis, is an F-type main-sequence star approximately 51 light-years away in the constellation of Boötes. It is a binary star system, with the secondary star being a red dwarf. In 1999, an extrasolar planet was detected orbiting the primary star. In December 2020, astronomers may have observed, for the first time, radio emissions from a planet beyond the Solar System. According to the researchers: "The signal is from the Tau Boötis system, which contains a binary star and an exoplanet. We make the case for an emission by the planet itself."

HD 224693, also named Axólotl, is a star in the equatorial constellation of Cetus, and is positioned near the western constellation border with Aquarius. It can be viewed with a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.23. Based on parallax measurements, the object is located at a distance of approximately 306 light years from the Sun. It is drifting further away with a radial velocity of 1.5 km/s.

HAT-P-6 also named Sterrennacht is a star in the constellation Andromeda, located approximately 895 light years or 274 parsecs away from the Earth. It is an F-type star, implying that it is hotter and more massive than the Sun. The apparent magnitude of the star is +10.54, which means that it can only be visible through the telescope. The absolute magnitude of +3.36 is brighter than the Sun's +4.83, meaning that the star itself is brighter than the Sun. A search for a binary companion star using adaptive optics at the MMT Observatory turned out negative.

<span class="mw-page-title-main">HAT-P-6b</span> Extrasolar planet in the Andromeda constellation

HAT-P-6b is a transiting extrasolar planet discovered by Noyes et al. on October 15, 2007. It is located approximately 910 light-years away in the constellation of Andromeda, orbiting the star HAT-P-6. This hot Jupiter planet orbits with a semi-major axis of about 0.05 AU, and takes 92 hours, 28 minutes, 17 seconds to orbit the star. It has true mass of 5.7% greater than Jupiter and a radius 33% greater than Jupiter, corresponding to a density of 0.583 g/cm3, which is less than water.

HD 16175 is a 7th magnitude G-type star with temperature about 6000 K located 196 light-years away in the Andromeda constellation. This star is only visible through binoculars or better equipment; it is also 3.3 times more luminous, is 1.34 times more massive, and has a radius 1.66 times bigger than our local star.

WASP-5 is a magnitude 12 G-type main-sequence star located about 1,020 light-years away in the Phoenix constellation. The star is likely older than the Sun, slightly enriched in heavy elements and is rotating rapidly, being spun up by the tides raised by the giant planet on a close orbit.

CoRoT-4 is a yellow-white dwarf main-sequence star in the constellation Monoceros.

HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.

HAT-P-11, also designated GSC 03561-02092 and Kepler-3, is an orange dwarf metal rich star about 123 light-years away in the constellation Cygnus. This star is notable for its relatively large rate of proper motion. The magnitude of this star is about 9, which means it is not visible to the naked eye but can be seen with a medium-sized amateur telescope on a clear dark night. The age of this star is about 6.5 billion years.

HAT-P-12 is a magnitude 13 low-metallicity K dwarf star approximately 463 light years away in the constellation Canes Venatici, which hosts one known exoplanet.

CoRoT-6 is a magnitude 13.9 star located in the Ophiuchus constellation.

BD−17 63 is a low-mass K-type main-sequence star in the southern constellation Cetus. It is a 10th magnitude star at a distance of 113 light-years from Earth. The star is rotating slowly with a negligible level of magnetic activity and an age of over 4 billion years.

<span class="mw-page-title-main">HAT-P-14b</span> Exoplanet in the constellation of Hercules

HAT-P-14b, officially named Sissi also known as WASP-27b, is an extrasolar planet located approximately 224.2 ± 0.6 parsecs (731.2 ± 2.0 ly) away in the constellation of Hercules, orbiting the 10th magnitude F-type main-sequence star HAT-P-14. This planet was discovered in 2010 by the HATNet Project using the transit method. It was independently detected by the SuperWASP project.

Kepler-39 is an F-type main sequence star located in the constellation Cygnus. It is located about 3,560 light-years away. One known substellar companion orbits it, Kepler-39b.

<span class="mw-page-title-main">WASP-21</span> Star in the constellation Pegasus

WASP-21 is a G-type star that is reaching the end of its main sequence lifetime approximately 850 light years from Earth in the constellation of Pegasus. The star is relatively metal-poor, having 40% of heavy elements compared to the Sun. Kinematically, WASP-21 belongs to the thick disk of the Milky Way. It has an exoplanet named WASP-21b.

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'.

HAT-P-26 is a K-type main-sequence star about 466 light-years away. A survey in 2015 did not find any stellar companions in orbit around it, although a red dwarf companion with a temperature 4000+100
−350 K is suspected on wide orbit.

HAT-P-20 is a K-type main-sequence star about 233 light-years away. The star has a strong starspot activity, and its equatorial plane is misaligned by 36+10
−12° with the planetary orbit. Although star with a giant planet on close orbit is expected to be spun-up by tidal forces, only weak indications of tidal spin-up were detected.

HAT-P-15 is a G-type main-sequence star about 630 light-years away. The star is older than Sun yet has a concentration of heavy elements roughly 190% of solar abundance. The star has no noticeable starspot activity.

BD+00 316 is an ordinary star with a close-orbiting planetary companion in the equatorial constellation of Cetus. It is also known as WASP-71 since 2019; BD+00 316 is the stellar identifier from the Bonner Durchmusterung catalogue. With an apparent visual magnitude of 10.56, it is too faint to be visible to the naked eye. This star is located at a distance of 1,160 light-years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 7.7 km/s.

References

  1. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  2. 1 2 HAT-P-21 -- Star
  3. ↑ Stassun, Keivan G.; Collins, Karen A.; Gaudi, B. Scott (2016), "Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes", The Astronomical Journal, 153 (3): 136, arXiv: 1609.04389 , Bibcode:2017AJ....153..136S, doi: 10.3847/1538-3881/aa5df3 , S2CID   119219062
  4. 1 2 Maxted, P. F. L.; Serenelli, A. M.; Southworth, J. (2015), "A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars", Astronomy & Astrophysics, 577: A90, arXiv: 1503.09111 , Bibcode:2015A&A...577A..90M, doi:10.1051/0004-6361/201525774, S2CID   53324330
  5. 1 2 Damiani, C.; Lanza, A. F. (2011), "Prospecting transit duration variations in extrasolar planetary systems", Astronomy & Astrophysics, 535: A116, arXiv: 1109.0936 , Bibcode:2011A&A...535A.116D, doi:10.1051/0004-6361/201117207, S2CID   118460941
  6. ↑ Wöllert, Maria; Brandner, Wolfgang; Bergfors, Carolina; Henning, Thomas (2015), "A Lucky Imaging search for stellar companions to transiting planet host stars", Astronomy & Astrophysics, 575: A23, arXiv: 1507.01938 , Bibcode:2015A&A...575A..23W, doi:10.1051/0004-6361/201424091, S2CID   119250579
  7. ↑ "IAU 100 NameExoWorlds Approved Names". Archived from the original on 2019-12-19. Retrieved 2020-07-08.
  8. 1 2 Bakos, G. Á.; Hartman, J.; Torres, G.; Latham, D. W.; Kovács, Géza; Noyes, R. W.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.; Kipping, D.; Esquerdo, G. A.; Shporer, A.; Béky, B.; Buchhave, L. A.; Perumpilly, G.; Everett, M.; Sasselov, D. D.; Stefanik, R. P.; Lázár, J.; Papp, I.; Sári, P. (2010), "HAT-P-20b–HAT-P-23b: FOUR MASSIVE TRANSITING EXTRASOLAR PLANETS", The Astrophysical Journal, 742 (2): 116, arXiv: 1008.3388 , doi:10.1088/0004-637X/742/2/116, S2CID   119182075
  9. ↑ Mancini, L.; et al. (2022), "The GAPS Programme at TNG", Astronomy & Astrophysics, 664: A162, arXiv: 2205.10549 , doi:10.1051/0004-6361/202243742, S2CID   248986121
  10. ↑ Davoudi, F.; Jafarzadeh, S.J.; Poro, A.; Basturk, O.; Mesforoush, S.; Fasihi Harandi, A.; Gozarandi, M.J.; Zare Mehrjardi, Z.; Maley, P.D.; Khakpash, S.; Rokni, K.; Sarostad, A. (2020), "Light Curve Analysis of Ground‐Based Data from Exoplanets Transit Database", New Astronomy, 76: 101305, arXiv: 1910.11438 , Bibcode:2020NewA...7601305D, doi:10.1016/j.newast.2019.101305, S2CID   202931761
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