SZ Lyncis

SZ Lyncis

A light curve for SZ Lyncis, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Lynx
Right ascension 08h 09m 35.749s[2]
Declination +44° 28′ 17.60″[2]
Apparent magnitude (V) 9.58[3] (9.08 – 9.72)[4]
Characteristics
Spectral type F0 IV-V[5] + F2 V – K3 V[6]
B−V color index 0.255±0.041[3]
Variable type δ Sct[4]
Astrometry
Radial velocity (Rv)34.17±0.04[5] km/s
Proper motion (μ) RA: −12.822 mas/yr[2]
Dec.: −26.584 mas/yr[2]
Parallax (π)1.9104 ± 0.1127 mas[2]
Distance1,700 ± 100 ly
(520 ± 30 pc)
Orbit[6]
Period (P)1,181.1±0.8 d
Semi-major axis (a)≥ 152.3 ± 0.8 Gm (1.0181 ± 0.0053 AU)
Eccentricity (e)0.188±0.005
Inclination (i)39±17.7[7]°
Periastron epoch (T)2,445,799.5±6.6 JD
Argument of periastron (ω)
(secondary)		99.0±2.3°
Semi-amplitude (K1)
(primary)		9.55±0.05 km/s
Details
Primary
Mass1.7–2.0[8] M☉
Radius2.68[8] R☉
Surface gravity (log g)3.9±0.08[9] cgs
Temperature7,142±3.96[9] K
Metallicity [Fe/H]0.00±0.04[9] dex
Rotational velocity (v sin i)40[10] km/s
Other designations
SZ Lyn, BD+44°1718, HD 67390, HIP 39960, SAO 42201[11]
Database references
SIMBADdata

SZ Lyncis is a binary star system in the northern constellation of Lynx, abbreviated SZ Lyn. It is a variable star with an apparent visual magnitude that fluctuates around 9.58,[3] which is too faint to be visible to the naked eye. The distance to this system is approximately 1,700 light years based on parallax measurements,[2] and it is drifting further away with a radial velocity of 34 km/s.[5]

The variability of this system was announced in 1949 by C. Hoffmeister.[12] V. Zessewitch generated a light curve from photographic observations, showing a period of 0.25 days.[13] H. Schneller in 1961 classified it as a short-period RR Lyrae variable.[14] O. J. Eggen in 1962 found a period of 0.12 days, or half that of earlier measurements.[13] P. Broglia in 1963 noted that the ~0.5 magnitude amplitude variation of SZ Lyn is more consistent with a dwarf Cepheid of the AI Velorum type[15] (later termed a Delta Scuti variable).[16]

Comparison of the times of maximum light by A. M. van Genderen in 1967 showed a variation in the period. This followed a sine wave with a period of 1,129 days.[17] In 1975, T. G. Barnes and T. J. Moffett confirmed the period variation and suggested it is being caused by a light-travel time effect in a single-lined spectroscopic binary with an orbital period of 3.14 years.[15] Radial velocity measurements by C. Bardin and M. Imbert in 1984 confirmed the binary nature of this system.[16] Updated orbital elements were published by T. J. Moffett and associates in 1988.[6]

This is a spectroscopic binary system with an orbital period of 3.2337 ± 0.0022 years and an eccentricity (ovalness) of 0.19.[6] A decrease in the longitude of the periapsis has been detected, which may indicate that the secondary component is actually a close binary.[7] The primary component is a Delta Scuti variable with a main pulsation frequency of 8.296943±0.000002 cycles per day. 23 frequencies have been identified, of which 14 are multiples of the main frequency. Models of the stellar properties suggest that it is near the end of its core hydrogen burning stage, or has just begun shell burning.[8] The secondary is likely a main sequence star with a class in the range F2 V – K3 V.[6]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Samus_et_al_2017 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Pourbaix_et_al_2004 was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference Moffett_et_al_1988 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Li_et_al_2013 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Adassuriya_et_al_2021 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Koleva_Vazdekis_2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Rodriguez_et_al_2000 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 Gazeas_Niarchos_2005 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Eggen_1962 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Schneller_1961 was invoked but never defined (see the help page).
  15. ^ a b Cite error: The named reference Barnes_Moffett_1975 was invoked but never defined (see the help page).
  16. ^ a b Cite error: The named reference Bardin_Imbert_1984 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference van_Genderen_1967 was invoked but never defined (see the help page).