Astronomy and Astrophysics – Astronomy
Scientific paper
Aug 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009pasj...61..707x&link_type=abstract
Publications of the Astronomical Society of Japan, Vol.61, No.4, pp.707--711
Astronomy and Astrophysics
Astronomy
Stars: Binaries: Close, Stars: Binaries : Eclipsing, Stars: Evolution, Stars: Individual (Df Hydrae), Stars : Multiple
Scientific paper
Combining our six new determined times of light minimum obtained from 2001 to 2007 with others compiled from the literature, we investigated the period changes of DF Hydrae. The general trend of the O - C curve based on all available data reveals that the period of the binary star is increasing continuously at a rate of dP/dt = + 1.11(±0.02) × 10-7dyr-1. After the long-term period increase was removed from the O - C diagram, it was discovered that the residuals of the CCD and photoelectric observations suggest a small-amplitude cyclic oscillation with a period of 21.5years. The continuous period increase can be explained by mass transfer from the secondary to the primary, indicating that DF Hydrae is on the TRO-controlled stage of the evolutionary scenario proposed by Qian. The cyclic period variation suggests that DF Hydrae is a triple system containing a cool tertiary component with a mass of M3sin i' = 0.21Modot in a 21.5-year orbit. By removing angular momentum from the central binary system via Kozai oscillation or a combination of the Kozai cycle and tidal friction, the tertiary companion may play an important role for the formation and evolution of the contact system, which makes the eclipsing pair to have a short initial orbital period (i.e., P < 5d). In that case, the detached progenitor of DF Hydrae evolves into the present contact configuration via a combination of magnetic braking and a case A mass transfer.
Tao Xia
Tian Yongpo
Xiang Fuyuan
Xie Wenli
No associations
LandOfFree
Period Changes of DF Hydrae: Evidence of Mass Transfer and the Presence of a Cool Tertiary Companion does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Period Changes of DF Hydrae: Evidence of Mass Transfer and the Presence of a Cool Tertiary Companion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Period Changes of DF Hydrae: Evidence of Mass Transfer and the Presence of a Cool Tertiary Companion will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1300145