2001A&A...379..878E -
Astronomy and Astrophysics, volume 379, 878-883 (2001/12-1)
The light and period changes of RT Andromedae.
ERDEM A., DEMIRCAN O. and GUERE M.
Abstract (from CDS):
The nature of the long-term orbital period variation and the light level variation of RT And was studied based on all available photometric observations. The (O-C) diagram formed by all available times of eclipse minima could be either of a quasi-sinusoidal form superimposed on a parabolic form, or a long period sinusoidal form. The quasi-sinusoidal form with an amplitude of ∼0.002 days and a period of ∼65 years could be due to a cyclic magnetic activity modulation on the orbital period of the system. Applegate's theory (Applegate, 1992ApJ...385..621A), in this case, predicts an ∼3kG mean subsurface magnetic field for the primary component of the system. The parabolic form corresponds to a secular period decrease of about 3x10–9m☉/yr caused by mass loss from the system, and the long-period sinusoidal form with an amplitude of ∼0.02 days and a period of ∼105 years corresponds to a secular period change caused by the light-time effect due to an unseen third star in the system. It was estimated that the unseen third star should be a low mass (lower than 0.6m☉) and faint (∼5mag fainter than the system RT And) star, whose detection is almost impossible. Future data will add information on the nature of the secular (O-C) variation. Secular light level variation of the system was found to be irregular and no correlation was detected with the orbital period variation.
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Journal keyword(s):
stars: binaries: eclipsing - stars: individual: RT And
(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
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value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options
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[error] : error of the corresponding value displayed before
(wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or '∼'(unknown)
quality : flag of quality ( A=best quality -> E=worst quality, ∼=unknown quality)
References (370 between 1850 and 2024) (Total 370)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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