RT Persei is avariable star system in the northernconstellation ofPerseus, abbreviated RT Per. It is aneclipsing binary system with anorbital period of 0.84940032 d (20.386 h). At peak brightness the system has anapparent 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 onparallax measurements.[2] It is drifting closer with a heliocentricradial velocity of about −12 km/s.[5]
This is asemidetached binary system with a circular orbit where the secondary component is filling itsRoche lobe and losing mass.[7] The primary component is anF-type main-sequence star with astellar 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 moreevolvedsubgiant 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 andangular momentum. Measured decreases in the period may be variously explained by spin-orbit coupling and interaction of thestellar 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 least2.67 AU with aneccentricity (ovalness) of 0.34.[15]
^abcdeMalkov, Oleg Yu (2020), "Semidetached double-lined eclipsing binaries: Stellar parameters and rare classes",Monthly Notices of the Royal Astronomical Society,491 (4):5489–5497,Bibcode:2020MNRAS.491.5489M,doi:10.1093/mnras/stz3363.
^abWilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities",Washington, Carnegie Institute of Washington, D.C.,Bibcode:1953GCRV..C......0W.
^Dugan, Raymond Smith (1911), "The Algol-System RT Persei",Contributions from the Princeton University Observatory,1:3–47,Bibcode:1911CoPri...1....3D.
^Dugan, Raymond Smith (1938), "Further Observations of RT Persei and an Attempted Explanation of the Change in Period",Contributions from the Princeton University Observatory,17:1–14,Bibcode:1938CoPri..17....1D.
Sanwal, B. B.; Chaubey, U. S. (December 1979), "On the lightcurve and orbital elements of binary star RT Persei",Bulletin of the Astronomical Society of India,7: 118,Bibcode:1979BASI....7..118S.
Todoran, I. (October 1979), "Period Changes of RT Persei",Information Bulletin on Variable Stars,1687: 1,Bibcode:1979IBVS.1687....1T.
Mancuso, S.; Milano, L. (February 1976), "Photoelectric V Light Curve of the Eclipsing Binary RT Persei",Information Bulletin on Variable Stars,1102: 1,Bibcode:1976IBVS.1102....1M.
