VZ Cancri

VZ Cancri

A light curve for VZ Cancri, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Cancer
Right ascension 08h 40m 52.125s[2]
Declination +09° 49′ 27.15″[2]
Apparent magnitude (V) 7.18 to 7.91[3]
Characteristics
Spectral type F2 III[4]
B−V color index 0.288±0.020[5]
Variable type δ Sct[3]
Astrometry
Radial velocity (Rv)25.2±0.4[6] km/s
Proper motion (μ) RA: −29.005 mas/yr[2]
Dec.: −15.856 mas/yr[2]
Parallax (π)4.5062 ± 0.0268 mas[2]
Distance724 ± 4 ly
(222 ± 1 pc)
Absolute magnitude (MV)1.79[5]
Details
Mass1.60[7] M☉
Radius2.90[8] R☉
Luminosity15.96[5] L☉
Surface gravity (log g)3.4±0.2[4] cgs
Temperature6,909±219[7] K
Metallicity [Fe/H]−0.41[7] dex
Rotational velocity (v sin i)26±1[4] km/s
Age1.70[7] Gyr
Other designations
VZ Cnc, BD+10°1848, HD 73857, HIP 42594, SAO 98035, PPM 154840[9]
Database references
SIMBADdata

VZ Cancri is a variable star in the constellation Cancer, abbreviated VZ Cnc. It varies in brightness with a period of 0.178364 days, from an apparent visual magnitude of 7.18 down to 7.91,[3] which lies below the typical threshold of visibility for the naked eye. The distance to this star is approximately 724 light years based on parallax measurements,[2] and it is receding from the Sun with a radial velocity of 25 km/s.[6]

This star was discovered to vary in brightness by B. S. Whitney in 1950, and was classified as a cluster-type Cepheid variable,[10] or RR Lyrae star.[11] In 1955, W. S. Fitch found the light curve to be variable and discovered a beat period of 0.716292 d,[12] from which is inferred a second pulsation period of 0.1428041 days.[13] H. A. Abt found that the stellar class of this star varied from A7–A9 III during peak brightness to F1–F2 III at minimum.[14] After H. J. Smith pointed out the distinctiveness of short period RR Lyrae variables in 1956, VZ Cnc has been grouped under the category of Delta Scuti variables.[15]

The star is located near the center of the instability strip.[13] Both pulsation periods for this star are in the first and second overtone;[16] it appears to lack a fundamental mode, possibly as a result of helium depletion in the outer atmosphere.[13] In 1994, an examination of five decades of data on this star suggested a variation in the period of maximum light with a cycle length of 49.3 years.[17] This could be the result of previously undetected pulsation frequencies.[16]

  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 Samus_et_al_2017 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Kahraman_Aliçavuş_2017 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov_2006 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Casagrande_et_al_2011 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Fernley_et_al_1987 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 Whitney_1950 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Joy_Wilson_1950 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Fitch_1955 was invoked but never defined (see the help page).
  13. ^ a b c Cite error: The named reference Cox_et_al_1984 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Abt_1955 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Breger_1979 was invoked but never defined (see the help page).
  16. ^ a b Cite error: The named reference Fu_Jiang_1999 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Arellano_Ferro_et_al_1994 was invoked but never defined (see the help page).