2018 schedule
Sat 31st
14:00-14:30
Photometry, spectroscopy and radial velocities of the near contact binary V0775 Cen and the contact binary TW Cru
David J. W. Moriarty
AAQ, VSS, UQ
Photometric and spectroscopic analyses of V0775 Cen, a near contact binary with a period of 16 hours and TW Cru, a contact binary with a period of 9 h, indicate both are triple systems. The V0775 Cen spectra are consistent with catalogue values of F0 IV for the primary component; its mass is 1.6 solar and radius 1.7 solar. The effective temperature of the secondary star indicates it has a spectral type of about K4, and its mass is 0.5 solar, yet with a radius of 1.1 solar, it has evolved well past terminal age main sequence. Episodes of emission in the H Balmer and metal lines of TW Cru confirm the conclusion from previously published photometric studies that it is chromospherically active.
Astronomy:
Amateur astronomer since 1956; member Astronomical Society of South
Australia 1957 - 1969. Member of Astronomical Association of Qld since
1982.
Currently, Emeritus Professor, Honorary Senior Fellow with the
Astrophysics group at The University of Queensland (UQ).
1966 – 1969 Ph.D. thesis studies on oxidation of inorganic sulphur
compounds by thiobacilli.
1969-1973: Biochemist-Microbiologist quantifying carbon and nitrogen
cycles in Lake George, Uganda, with the Royal Society African Freshwater
Biological Team, and at Nottingham University, UK.
1973-1975: Queen's Fellow in Marine Science at UQ.
1975 - 1993: Researcher with the CSIRO Marine Divisions. 1992: Guest
Professor in Marine Microbiology, Gothenberg University, Sweden.
1997-2013 Honorary Professor, Centre for Marine Studies, UQ.
Qualifications: B.Ag. Sc. (Hons.); Ph.D., D.Sc. FASM