SISTEM CD TAU: PARAMETER ABSOLUT DAN ATMOSFER BINTANG DARI SPEKTROSKOPI RESOLUSI TINGGI DENGAN GAOES

• Main Author: TRIONO PURI JATMIKO, AGUS
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/9834
• Institution: Institut Teknologi Bandung

High resolution spectroscopy observation of eclipsing binary system of CD Tau has been carried out using Gunma Astronomical Observatory Echelle Spectrograph (GAOES), attached in 1.5m reflector telescope in Gunma Astronomical Observatory, Japan. It covers almost full phase coverage from 2004 until 2008. The standard reduction process has been done using Iraf and heliocentric radial velocities for each component were derived using cross–corellation method. The next step was constructing a radial velocity curve of the system. Absolute parameters of the system were determined by elaborating photometry results from Ribas et al. (1999) [30] with orbital parameters from this work. The orbital parameters were derived by fitting a radial velocity curve using differential correction method. The goodness of fit is measured by ?2 value. Radial velocity curve’s solution from this work are: mass ratio q = M2/M1 = 0.888±0.009, systemic velocity ? = ?29.4± 0.4 kms?1, and separation between two components a = 13.42 ± 0.07 R. Absolute parameters of CD Tau which are obtained in this work are: mass of primary component M1 = 1.462 ± 0.015 M, mass of secondary component M2 = 1.298 ± 0.018 M, radius of primary component R1 = 1.786 ± 0.016 R, and radius of secondary component R2 = 1.574 ± 0.021 R. Fitting process has been done using UlySS, a full spectrum fitting package which been optimized to use all measured signal. Initial values of stellar parameters i.e effective temperature Teff , logaritm of surface gravity log g, and microturbulent velocity ?t was deduced using Spectrum package from Gray (2009) [10] and have been iterated until converge to the final solutions. The best fitting results for CD Tau from this work are: Teff = 7270.55 ± 42.56 K and log g = 3.88 ± 0.05.