RT Persei

RT Persei

A light curve for RT Persei, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 23m 40.399s[2]
Declination 46° 34′ 35.84″[2]
Apparent magnitude (V) 10.46
Min1: 11.74
Min2: 10.67[3]
Characteristics
Spectral type F5V + G7IV[4]
Variable type Semidetached Algol[3]
Astrometry
Radial velocity (Rv)−12±2[5] km/s
Proper motion (μ) RA: 13.084 mas/yr[2]
Dec.: 23.763 mas/yr[2]
Parallax (π)5.1901 ± 0.0189 mas[2]
Distance628 ± 2 ly
(192.7 ± 0.7 pc)
Orbit[6]
Period (P)0.8494 d
Semi-major axis (a)4.190[4]"
(4.2 AU[7])
Eccentricity (e)0.00
Inclination (i)~86[7]°
Periastron epoch (T)2,417,861.407 HJD
Argument of periastron (ω)
(secondary)		0.00°
Semi-amplitude (K1)
(primary)		55.0[8] km/s
Semi-amplitude (K2)
(secondary)		194.7[8] km/s
Details[4]
Primary
Mass1.08 M☉
Radius1.20 R☉
Luminosity2.24 L☉
Surface gravity (log g)4.32[9] cgs
Temperature6,460 K
Metallicity [Fe/H]−0.28[9] dex
Secondary
Mass0.30 M☉
Radius1.08 R☉
Luminosity0.49 L☉
Temperature4,650 K
Other designations
RT Per, BD+46°740, HIP 15811[10]
Database references
SIMBADdata

RT Persei is a variable star system in the northern constellation of Perseus, abbreviated RT Per. It is an eclipsing binary system with an orbital period of 0.84940032 d (20.386 h). At peak brightness the system has an apparent visual magnitude of 10.46, which is too faint to be viewed with the naked eye. During the eclipse of the primary this decreases to magnitude 11.74, then to magnitude 10.67 with the secondary eclipse.[3] The distance to this system is approximately 628 light years based on parallax measurements.[2] It is drifting closer with a heliocentric radial velocity of about −12 km/s.[5]

In 1905 this system was found to be an Algol variable by Lidiya Tseraskaya.[11] K. Graff determined a period of 0.84943 days. In 1911, R. S. Dugan published evidence for a secondary eclipse and noted the influence of ellipticity of the components on its light curve, as well as influences from their mutual reflection and heating.[12] By 1938, the period of the system had been found to vary, suggesting the perturbing influence of a third body.[13] D. J. K. O'Connell in 1951 found the light curve of RT Per to be asymmetrical, a phenomenon later termed the O'Connell effect.[14][15]

This is a semidetached binary system with a circular orbit where the secondary component is filling its Roche lobe and losing mass.[7] The primary component is an F-type main-sequence star with a stellar classification of F5V.[4] It has 1.08 times the mass of the Sun, 1.20 times the Sun's radius,[15] and is close to filling its Roche lobe.[7] The secondary is a more evolved subgiant star with a class of G7IV.[4] It has just 30% of the Sun's mass but has expanded to 108% of the solar radius.[15]

The system has undergone irregular jumps in orbital period, which are common among Algol-type variables that are exchanging mass and angular momentum. Measured decreases in the period may be variously explained by spin-orbit coupling and interaction of the stellar magnetic fields.[15] Based upon long-term trends in the light curve, an unseen third component is moving in an elliptical orbit with the inner pair over a period of 41.9 years. It is estimated to be orbiting at a distance of at least 2.67 AU with an eccentricity (ovalness) of 0.34.[15]

  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 d e Cite error: The named reference Malkov_2020 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Wilson_1953 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Struve_1947 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Edalti_Zeinali_1996 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Lu_1990 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Qian_et_al_2018 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Ceraski_1904 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Dugan_1911 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Dugan_1938 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Drilling_Landolt_1972 was invoked but never defined (see the help page).
  15. ^ a b c d e Cite error: The named reference Qian_2001 was invoked but never defined (see the help page).