Z Andromedae

Not to be confused with Zeta Andromedae.
Z Andromedae
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 33m 39.9551s[1]
Declination +48° 49′ 05.974″[1]
Apparent magnitude (V) 7.7 - 11.3[2]
Characteristics
Spectral type M2III + B1eq[3]
U−B color index −0.49[4]
B−V color index +1.35[4]
Variable type Z And[2]
Astrometry
Radial velocity (Rv)-0.59[5] km/s
Proper motion (μ) RA: -1.606 ± 0.049[1] mas/yr
Dec.: -2.971 ± 0.040[1] mas/yr
Parallax (π)0.5123 ± 0.0300 mas[1]
Distance6,400 ± 400 ly
(2,000 ± 100 pc)
Orbit
Period (P)759.0±1.9[6] days
Eccentricity (e)0.0[6]
Inclination (i)47±12[7]°
Semi-amplitude (K1)
(primary)		6.73±0.22[6] km/s
Details
Red giant
Mass2[6] M☉
Radius85[3] R☉
Luminosity880[8] L☉
Temperature3,400[3] K
White dwarf
Mass0.75[6] M☉
Radius0.17 - 0.36[9] R☉
Luminosity1,500 - 9,800[9] L☉
Temperature90,000 - 150,000[9] K
Rotation1682.6 ± 0.6 s[10]
Other designations
MWC 416, HD 221650, HIP 116287, SAO 53146, PPM 64386, AG+48° 2087, GCRV 14773, IRAS 23312+4832, HV 193, AN 41.1901, JP11 3636, TYC 3645-2066-1, BD+48° 4093, GSC 03645-02066, 2MASS J23333994+4849059, AAVSO 2328+48, 2E 2331.6+4834, PLX 5697, 2E 4735
Database references
SIMBADdata
Data sources:
Hipparcos Catalogue,
CCDM (2002),
Bright Star Catalogue (5th rev. ed.)

Z Andromedae is a binary star system consisting of a red giant and a white dwarf. It is the prototype of a type of cataclysmic variable star known as symbiotic variable stars or simply Z Andromedae variables. The brightness of those stars vary over time, showing a quiescent, more stable phase and then an active one with a more pronounced variability and stronger brightening and/or dimming.[11]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference shenavrin was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference ibvs was invoked but never defined (see the help page).
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  6. ^ a b c d e Cite error: The named reference fekel was invoked but never defined (see the help page).
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  8. ^ Cite error: The named reference skopal2003 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference sokoloski2006 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Sokoloski1999 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference daviddarling was invoked but never defined (see the help page).