AAVSO: American Association of Variable Star Observers

QZ Carinae—Orbit of the Two Binary Pairs

Volume 48 number 1 (2020)

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Mark Blackford
Variable Stars South (VSS), Congarinni Observatory, Congarinni, NSW, Australia 2447; markgblackford@outlook.com
Stan Walker
Variable Stars South (VSS), Wharemaru Observatory, Waiharara, Northland, New Zealand 0486
Edwin Budding
Variable Stars South (VSS), Carter Observatory, Kelburn, Wellington, New Zealand 6012
Greg Bolt
Variable Stars South (VSS), Craigie Observatory, Craigie, WA, Australia 6025
Dave Blane
Variable Stars South (VSS), and Astronomical Society of Southern Africa (ASSA), Henley Observatory, Henley on Klip, Gauteng, South Africa
Terry Bohlsen
Variable Stars South (VSS), and Southern Astro Spectroscopy Email Ring (SASER), Mirranook Observatory, Armidale, NSW, Australia, 2350
Anthony Moffat
BRITE Team, Département de physique, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
Herbert Pablo
BRITE Team, American Association of Variable Star Observers, 49 Bay State Road, Cambridge, MA 02138
Andrzej Pigulski
BRITE Team, Instytut Astronomiczny, Uniwersytet Wrocławski, Wrocław, Poland
Adam Popowicz
BRITE Team, Department of Automatic Control, Electronics and Informatics, Silesian University of Technology, Gliwice, Poland
Gregg Wade
BRITE Team, Department of Physics and Space Science, Royal Military College of Canada, P.O. Box 17000, Station Forces, Kingston, ON K7K 7B4, Canada
Konstanze Zwintz
BRITE Team, Universität Innsbruck, Institut für Astro- und Teilchenphysik, Technikerstrasse 25, A-6020 Innsbruck, Austria


We present an updated O–C diagram of the light-time variations of the eclipsing binary (component B) in the system QZ Carinae as it moves in the long-period orbit around the non-eclipsing pair (component A). This includes new Variable Stars South members’ measures from 2017 to 2019, BRITE satellite observations in 2017 and 2018, and 100 previously unpublished measures made at Auckland Observatory from 1974 to 1978. We conclude that QZ Carinae has not yet completed one orbit of the two pairs since discovery in 1971. The duration of totality of primary eclipses was measured to be 0.295 ± 0.02 day (7.08 ± 0.48 hours), rather longer than earlier values from light curve models. Other observational findings include the shape of primary and secondary eclipses and small-scale short-term brightness changes.