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تسجيل مستخدم جديدThe TRENDS High-Contrast Imaging Survey. VII. Discovery of a Nearby Sirius-like White Dwarf System (HD 169889)
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Monitoring the long-term radial velocity (RV) and acceleration of nearby stars has proven an effective method for directly detecting binary and substellar companions. Some fraction of nearby RV trend systems are expected to be comprised of compact objects that likewise induce a systemic Doppler signal. In this paper, we report the discovery of a white dwarf companion found to orbit the nearby ($pi = 28.297 pm 0.066$ mas) G9 V star HD 169889. High-contrast imaging observations using NIRC2 at Keck and LMIRCam at the LBT uncover the ($Delta H = 9.76 pm 0.16$, $Delta L = 9.60 pm 0.03$) companion at an angular separation of 0.8 (28 au). Thirteen years of precise Doppler observations reveal a steep linear acceleration in RV time series and place a dynamical constraint on the companion mass of $M geq 0.369 pm 0.010 M_{odot}$. This Sirius-like system adds to the census of white dwarf companions suspected to be missing in the solar neighborhood.
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