HD 175740

HD 175740
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lyra
Right ascension 18h 54m 52.17758s[1]
Declination +41° 36′ 09.7934″[1]
Apparent magnitude (V) 5.46[2]
Characteristics
Spectral type K0III[3]
B−V color index 1.034±0.004[2]
Astrometry
Radial velocity (Rv)−9.52±0.13[4] km/s
Proper motion (μ) RA: −2.059[1] mas/yr
Dec.: −2.234[1] mas/yr
Parallax (π)12.2448 ± 0.0874 mas[1]
Distance266 ± 2 ly
(81.7 ± 0.6 pc)
Absolute magnitude (MV)0.89[2]
Details
Mass1.39[5] or 2.795[4] M☉
Radius10.17+0.35
−0.73[1] R☉
Luminosity49.90±0.45[1] L☉
Surface gravity (log g)2.8[6] cgs
Temperature4,811+181
−81[1] K
Metallicity [Fe/H]−0.01±0.06[2] dex
Rotational velocity (v sin i)4.0[6] km/s
Age4.78[5] Gyr
Other designations
BD+41°3177, GC 25972, HD 175740, HIP 92831, HR 7146, SAO 47909, WDS J18549+4136A[7]
Database references
SIMBADdata

HD 175740 is a single[8] star in the northern constellation of Lyra.[2] This object has an orange hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.46.[2] It is located at a distance of approximately 266 light years from the Sun based on parallax,[1] and has an absolute magnitude of 0.89.[2] The star is drifting closer with a radial velocity of −9.5 km/s, and is predicted to come as close as 31.7 light-years in around 8 million years.[4]

This is an aging giant star with a stellar classification of K0III,[3] having evolving off the main sequence after the supply of hydrogen at its core was exhausted. It is an estimated 4.78[5] billion years old with 1.39[5] times the mass of the Sun, although Bailer-Jones et al. (2018) give a higher estimate of 2.8[4] times the Sun's mass. The elemental composition of this star has made it the first giant to be a candidate solar sibling, suggesting it may have been born in the same star cluster as the Sun.[9] It has expanded to ten[1] times the girth of the Sun and is radiating 50[1] times the Sun's luminosity from its photosphere at an effective temperature of 4,811 K.[1]

HD 175740 has a magnitude 12.6 visual companion, located at an angular separation of 8.4″ along a position angle (PA) of 300°, as of 2013. A magnitude 11.5 companion lies at a separation of 24.1″ along a PA of 39°, as of 2014. Both were discovered by American astronomer G. W. Hough in 1887.[10]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference abt1985 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Bailer2018 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Luck2015 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Ramírez2014 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).