Phi Aquarii

Phi Aquarii
Location of φ Aquarii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 23h 14m 19.35965s[1]
Declination –06° 02′ 56.3986″[1]
Apparent magnitude (V) +4.223[2]
Characteristics
Spectral type M1.5 III[3]
U−B color index +1.897[2]
B−V color index +1.563[2]
Astrometry
Radial velocity (Rv)+2.48±0.32[4] km/s
Proper motion (μ) RA: +35.391[1] mas/yr
Dec.: –196.862[1] mas/yr
Parallax (π)14.6670 ± 0.4099 mas[1]
Distance222 ± 6 ly
(68 ± 2 pc)
Absolute magnitude (MV)0.30±0.120[5]
Details
Mass1.00±0.03[6] M☉
Radius34.77+1.83
−2.04[6] R☉
Luminosity207.7±25.2[6] L☉
Surface gravity (log g)1.5[4] cgs
Temperature3715±48[6] K
Rotational velocity (v sin i)6.7[4] km/s
Age10.97±0.83[6] Gyr
Other designations
φ Aqr, 90 Aquarii, BD–06°6170, FK5 1607, HD 219215, HIP 114724, HR 8834, SAO 146585[7]
Database references
SIMBADdata

Phi Aquarii, Latinized from φ 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 a combined apparent visual magnitude of +4.223.[2] Parallax measurements indicate its distance from Earth is roughly 222 light-years (68 parsecs),[1] and it is drifting further away with a radial velocity of +2.5 km/s.[4] It is 1.05 degrees south of the ecliptic so it is subject to lunar occultations.[9]

This is a spectroscopic binary star system with an estimated period of 2,500 days.[10] The primary component is a red giant star with a stellar classification of M1.5 III.[3] The outer envelope of this evolved star has expanded to 35 times the size of the Sun. The star has the same mass as the Sun.[6] It is radiating 208 times the luminosity of the Sun at an effective temperature of 3,715 K,[6] giving it the reddish hue of an M-type star.[11]

  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 sps1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference araa11_29 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference aj135_1_209 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference park2013 was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference Baines2018 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 mnras389_2_869 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference White1987 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference aaa498_2_627 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).