HD 195564

HD 195564
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Capricornus
Right ascension 20h 32m 23.695s[1]
Declination −09° 51′ 12.18″[1]
Apparent magnitude (V) 5.65[2]
Characteristics
Spectral type G2 V[3]
U−B color index +0.20[2]
B−V color index +0.68[2]
Astrometry
Radial velocity (Rv)+9.58[4] km/s
Proper motion (μ) RA: +309.736 mas/yr[1]
Dec.: +109.910 mas/yr[1]
Parallax (π)40.4241 ± 0.0497 mas[1]
Distance80.68 ± 0.10 ly
(24.74 ± 0.03 pc)
Details
HD 195564 A
Mass1.097[5] M☉
Radius1.867±0.083[5] R☉
Luminosity2.705±0.047[5] L☉
Surface gravity (log g)3.74[3] cgs
Temperature5421±118[5] K
Metallicity [Fe/H]+0.06[5] dex
Rotational velocity (v sin i)1.91[6] km/s
Age8.2[5] Gyr
HD 195564 B
Mass0.55[7] M☉
Other designations
BD−10° 5423, FK5 1536, GJ 792.1, HD 195564, HIP 101345, HR 7845, SAO 163665[8]
Database references
SIMBADdata
ARICNSdata

HD 195564 is the Henry Draper Catalogue designation for a star in the southern constellation of Capricornus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.65.[2] Parallax measurements give us an estimate of its distance as 81 light years. This is a candidate wide binary system as a faint companion star shares a common proper motion with the brighter primary component.[7]

Based upon the spectrum of light emitted by the primary, it has a stellar classification of G2 V.[3] This indicates that it is a G-type main sequence star that is generating energy through the process of thermonuclear fusion in its core region. It has an estimated mass of 1.097[5] times the mass of the Sun, but a measured radius that is 1.867 times as large.[5] As a result, it shines with 2.705 times the luminosity of the Sun.[5] The abundance of elements in this star is similar to that in the Sun, although it is an older star with an age of around 8.2 billion years.[5] The effective temperature of the stellar atmosphere is 5,421 K,[5] giving it the yellow-hued glow of an ordinary K-type star.[9]

The secondary companion has an apparent magnitude of 11.30,[10] and a mass just 55% that of the Sun.[7] As measured in 1965, it had an angular separation of 3.20″ from the primary, along a position angle of 27°[10] The pair orbit each other with an estimated period of around 510 years.[7]

In a paper published in April 2017, a candidate planet was found orbiting HD 195564 with a period of 5,404 days (14.80 yr).[11]

The HD 195564 planetary system[11]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b (unconfirmed) — — 5403.77251±164.1426 — — —
  1. ^ a b c d Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference GrayRO2003 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Nidever2002 was invoked but never defined (see the help page).
  5. ^ a b c d e f g h i j k Cite error: The named reference apj771_1_40 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference MartínezArnáiz2010 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference aj147_4_87 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Butler2017 was invoked but never defined (see the help page).