HD 190007

HD 190007

Four representative light curves for HD 190007, adapted from Burt et al. (2020)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila[2]
Right ascension 20h 02m 47.04569s[3]
Declination +03° 19′ 34.2658″[3]
Apparent magnitude (V) 7.46[1]
Characteristics
Evolutionary stage main sequence[4]
Spectral type K5 V[5]
U−B color index +1.09[6]
B−V color index +1.11[6]
Variable type BY Dra[7]
Astrometry
Radial velocity (Rv)−30.268±0.0013[8] km/s
Proper motion (μ) RA: −90.383 mas/yr[3]
Dec.: 119.430 mas/yr[3]
Parallax (π)78.6465 ± 0.0198 mas[3]
Distance41.47 ± 0.01 ly
(12.715 ± 0.003 pc)
Absolute magnitude (MV)6.91[2]
Details
Mass0.77±0.02[1] M☉
Radius0.80[9] R☉
Luminosity0.24[9] L☉
Surface gravity (log g)4.50[10] cgs
Temperature4,610±20[1] K
Metallicity [Fe/H]0.16[10] dex
Rotation28.626±0.046 d[1]
Other designations
V1654 Aql, BD+02°4076, GJ 775, HD 190007, HIP 98698, SAO 125379[11]
Database references
SIMBADdata
ARICNSdata

HD 190007, also known as Gliese 775, is a star with a close orbiting exoplanet in the constellation of Aquila. Parallax measurements by Gaia put the star at a distance of 41.5 light-years (12.7 parsecs) away from the Sun. It is drifting closer with a radial velocity of −30.3 km/s,[8] and is predicted to come within 11.8 light-years in 375,000 years.[12] The star has an absolute magnitude of 6.91,[2] but at its present distance the apparent visual magnitude is 7.46,[1] which is too faint to be viewed with the naked eye.

The spectrum of HD 190007 matches a K-type main-sequence star with a stellar classification of K5 V.[5] It is classified as a BY Draconis variable, showing a moderate level of magnetic activity in its chromosphere[4] with a suspected activity cycle lasting 13.7 years.[13] The star displays a mild enhancement of metals and its age is uncertain. It has 77%[1] of the mass of the Sun, 80% of the Sun's radius,[9] and is spinning with a rotation period of 28.6 days.[1] HD 190007 is radiating 24%[9] of the luminosity of the Sun from its photosphere at an effective temperature of 4,610 K.[1]

  1. ^ a b c d e f g h i Cite error: The named reference Burt2020 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference xhip was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Stalport2023 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference kirkpatrick1991 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference EgUBV was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Soubiran_et_al_2018 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference Chandler was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Mishenina was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Bailer-Jones_et_al_2018 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Obridko_et_al_2022 was invoked but never defined (see the help page).