π Lupi (Latinised to Pi Lupi) is a multiple star system in the southern constellation
Lupus. Two components form a wide binary pair with an orbital period of 517 years and a
semimajor axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...
of 1.59″. They belong to the Upper Centaurus Lupus component of the
Sco–Cen complex.
At least one of the components is a
spectroscopic binary and produces eclipses 15.5 days apart, making it an
eclipsing binary. There are also other brightness variations with a period of 16 hours that are likely to be pulsations of the
Slowly pulsating B-type star. The eclipses are shallow, with the brightness dropping by only 1% or about 0.01 magnitudes. The amplitude of the pulsations is even smaller.
[
π Lupi A (HR 5605, HD 133242) has been classified as a spectroscopic binary by at least two studies,][ but both components may be spectroscopic binaries.][
]
References
{{Stars of Lupus
Lupus (constellation)
Lupi, Pi
133242/3
Eclipsing binaries
5605 6
073807
Durchmusterung objects
B-type main-sequence stars
B-type subgiants
Upper Centaurus Lupus