Astronomy:HAT-P-27

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Short description: Star in the constellation Virgo
HAT-P-27
Observation data
Equinox J2000.0]] (ICRS)
Constellation Virgo
Right ascension  14h 51m 04.1870s[1]
Declination +05° 56′ 50.5482″[1]
Apparent magnitude (V) 12.214[2]
Characteristics
Evolutionary stage main-sequence star
Spectral type G8
Astrometry
Radial velocity (Rv)-15.901[1] km/s
Proper motion (μ) RA: -28.621[1] mas/yr
Dec.: -2.757[1] mas/yr
Parallax (π)4.9922 ± 0.0360[3] mas
Distance653 ± 5 ly
(200 ± 1 pc)
Orbit[4]
PrimaryHAT-P-27
CompanionHAT-P-27 B
Semi-major axis (a)0.656±0.021"
(131 AU)
Details[2]
Mass0.945±0.035 M
Radius0.898+0.054−0.039 R
Luminosity0.57+0.09−0.07 L
Surface gravity (log g)4.51±0.04 cgs
Temperature5300±90 K
Metallicity [Fe/H]0.29±0.10 dex
Rotation0.4±0.4
Rotational velocity (v sin i)0.6+0.7−0.4[5] km/s
Age4.4+3.8−2.6 Gyr
Other designations
HAT-P-27, Gaia DR2 1159336403336463872, GSC 00333-00351, 2MASS J14510418+0556505[1]
Database references
SIMBADdata

HAT-P-27, also known as WASP-40, is the primary of a binary star system about 650 light-years away. It is a G-type main-sequence star. The star's age is similar to the Sun's at 4.4 billion years.[2] HAT-P-27 is enriched in heavy elements, having a 195% concentration of iron compared to the Sun.

The very dim stellar companion was detected in 2015 at a projected separation of 0.656″[4] and proven to be physically bound to the system in 2016.[6]

Planetary system

In 2011 a transiting hot Jupiter type planet b was detected in a mildly eccentric orbit. The planetary equilibrium temperature is 1207±41 K.[2] The survey in 2013 failed to find any Rossiter-McLaughlin effect and therefore was unable to constrain the inclination of planetary orbit to the equatorial plane of the parent star.[5] No orbital decay was detected as in 2018, despite the close proximity of the planet to the star.[7]

The presence of an additional planet in the system has been suspected since 2015.[8]

The HAT-P-27 planetary system[2]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 0.660±0.033 MJ 0.0403±0.0005 3.039586±0.000012 0.078±0.047 85.0±0.2[5]° 1.038+0.077−0.058 RJ

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 "HAT-P-27". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HAT-P-27. 
  2. 2.0 2.1 2.2 2.3 2.4 Béky, B.; Bakos, G. Á.; Hartman, J.; Torres, G.; Latham, D. W.; Jordán, A.; Arriagada, P.; Bayliss, D. et al. (2011), "HAT-P-27b: A HOT JUPITER TRANSITING A G STAR ON A 3 DAY ORBIT", The Astrophysical Journal 734 (2): 109, doi:10.1088/0004-637X/734/2/109, Bibcode2011ApJ...734..109B 
  3. Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  4. 4.0 4.1 Wöllert, Maria; Brandner, Wolfgang (2015), "A Lucky Imaging search for stellar sources near 74 transit hosts", Astronomy & Astrophysics 579: A129, doi:10.1051/0004-6361/201526525, Bibcode2015A&A...579A.129W 
  5. 5.0 5.1 5.2 Brown, D. J. A.; Collier Cameron, A.; Díaz, R. F.; Doyle, A. P.; Gillon, M.; Lendl, M.; Smalley, B.; Triaud, A. H. M. J. et al. (2013), "Analysis of Spin-Orbit Alignment in the Wasp-32, Wasp-38, and Hat-P-27/Wasp-40 Systems", The Astrophysical Journal 760 (2): 139, doi:10.1088/0004-637X/760/2/139 
  6. Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Bryan, Marta; Crepp, Justin R.; Batygin, Konstantin; Crossfield, Ian; Hansen, Brad et al. (2016), "FRIENDS OF HOT JUPITERS. IV. STELLAR COMPANIONS BEYOND 50 au MIGHT FACILITATE GIANT PLANET FORMATION, BUT MOST ARE UNLIKELY TO CAUSE KOZAI–LIDOV MIGRATION", The Astrophysical Journal 827 (1): 8, doi:10.3847/0004-637X/827/1/8, Bibcode2016ApJ...827....8N 
  7. Penev, Kaloyan; Bouma, L. G.; Winn, Joshua N.; Hartman, Joel D. (2018), "EMPIRICAL TIDAL DISSIPATION IN EXOPLANET HOSTS FROM TIDAL SPIN–UP", The Astronomical Journal 155 (4): 165, doi:10.3847/1538-3881/aaaf71, PMID 31080254, Bibcode2018AJ....155..165P 
  8. Ground-based transit observations of the HAT-P-18,HAT-P-19, HAT-P-27/WASP40 and WASP-21 systems

Coordinates: Sky map 14h 51m 04.1870s, +05° 56′ 50.5482″