17 Aquarii

17 Aquarii
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 21h 22m 56.25866s[1]
Declination −09° 19′ 09.5823″[1]
Apparent magnitude (V) 5.99[2]
Characteristics
Spectral type K4/5 III[3]
B−V color index 1.516±0.008[2]
Astrometry
Radial velocity (Rv)18.2±2.9[4] km/s
Proper motion (μ) RA: −29.659[1] mas/yr
Dec.: −29.022[1] mas/yr
Parallax (π)4.9125 ± 0.1260 mas[1]
Distance660 ± 20 ly
(204 ± 5 pc)
Absolute magnitude (MV)−0.73[2]
Orbit[5]
Period (P)7,290 d
Eccentricity (e)0.4
Details
17 Aqr A
Luminosity495.46[2] L☉
Surface gravity (log g)1.74±0.14[6] cgs
Temperature3,951±14[6] K
Metallicity [Fe/H]−0.10±0.06[6] dex
Other designations
BD−09° 5728, FK5 3705, HD 203525, HIP 105574, HR 8175, SAO 145351[7]
Database references
SIMBADdata

17 Aquarii, abbreviated 17 Aqr, is a spectroscopic binary[5] star system in the constellation of Aquarius. 17 Aquarii is the Flamsteed designation. It appears to the naked eye as a faint sixth magnitude star, having a combined apparent visual magnitude of 5.99.[2] The distance to 17 Aqr can be estimated from its annual parallax shift of 4.9 mas,[1] which yields a separation of around 660 light years. It is moving further away with a heliocentric radial velocity of 18 km/s.[4]

A preliminary orbit for the pair gives a period of 20 years and an eccentricity of 0.4.[5] The primary component is an aging giant star with a stellar classification of K4/5 III.[3] It is radiating 495[2] times the Sun's luminosity from its photosphere at an effective temperature of 3,951 K.[6]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1999 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Famaey2009 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Wu2011 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).