Rho Aquarii

Rho Aquarii
Location of ρ Aquarii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 22h 20m 11.91830s[1]
Declination –07° 49′ 15.9742″[1]
Apparent magnitude (V) +5.34[2]
Characteristics
Spectral type B8 IIIp Mn:Hg:[3]
U−B color index –0.358[2]
B−V color index –0.057[2]
Astrometry
Radial velocity (Rv)–9[4] km/s
Proper motion (μ) RA: +13.201[1] mas/yr
Dec.: +0.030[1] mas/yr
Parallax (π)3.7483 ± 0.1608 mas[1]
Distance870 ± 40 ly
(270 ± 10 pc)
Absolute magnitude (MV)−1.78[5]
Orbit[6]
Period (P)220.41±0.10 d
Periastron epoch (T)2,418,548.7±7.4 JD
Semi-amplitude (K1)
(primary)		18.66±2.75 km/s
Details
A
Mass5.00±0.22[7] M☉
Luminosity1,035[7] L☉
Temperature12,593[8] K
Rotational velocity (v sin i)65[3] km/s
Other designations
ρ Aqr, 46 Aquarii, BD–08 5855, HD 211838, HIP 110273, HR 8512, SAO 146023[9]
Database references
SIMBADdata

Rho Aquarii, Latinized from ρ Aquarii, is the Bayer designation for a binary star[8] system in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of +5.34.[2] Based upon parallax measurements, this star is at a distance of roughly 870 light-years (270 parsecs) from Earth.[1] It is drifting closer with a radial velocity of –9 km/s.[4] The proximity of this star to the ecliptic means it is subject to lunar occultations.[10]

This is a single-lined spectroscopic binary, with the presence of a companion being revealed by Doppler shifts in the spectrum.[8] An initial orbital solution for the data gives an orbital period of 220.4 days.[6] The primary is a giant star with a stellar classification of B8 IIIp Mn:Hg:.[3] It is a candidate mercury-manganese star, showing a surfeit of these elements in the spectrum.[8] With five times the Sun's mass, this star is radiating 1,035[7] times as much luminosity from its outer atmosphere at an effective temperature of 12,593 K.[8] This heat gives it the blue-white hue of a B-type star.[11] The companion may be a variable star.[12]

  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 Cite error: The named reference saaoc8_59 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference apj573_1_359 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference gcrv was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Stickland_Weatherby_1984 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference an331_4_349 was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference aaa525_A97 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Hilaire1974 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference aaa429_317 was invoked but never defined (see the help page).