A tiny constellation in the southern sky, Apus represents a bird-of-paradise. Its name literally means “without feet”. In the western world at the time of Bayer, who first identified this constellation, the only existing specimen of birds-of-paradise there had their wings and feet removed. French astronomer, Lacaille, gave this constellation’s brighter stars Bayer Designations for the first time in 1756 and also cut the tail of this bird-of-paradise. Alpha Apodis is an orange giant with a diameter 48 times larger than that of the Sun. Beta Apodis is another giant star in this constellation, with a radius 11 times larger than that of the Sun. Gamma Apodis is a yellow giant star of the constellation, and Delta Apodis is a binary stellar system, consisting of an orange giant and a red giant star. No Apodis is the beating heart of the constellation, it’s a variable pulsating star. Its magnitude changes between 5.71 and 5.95, with pulsation periods of 26.2 and 26.6 days respectively. With the help of Doppler spectroscopy, two exoplanets hosted by two stars of these constellations were discovered. This method is being used very frequently these days in astronomy for discovering exoplanets. We encourage the curious readers to visit this Wikipedia page to know more about this powerful method – it contains so many physical concepts involved. Milky Way covers most of this constellation, thus, no galaxies here. But there are two globular clusters, NGC 6101 and IC 4499 namely, in Apus.
Globular clusters are spherical crowds of stars orbiting a galactic core. They owe their spherical shape to their stars being too strongly bound to each other by gravity. This also gives them a dense core at the center (a beautiful, nice example of this is Messier 80 located in the Scorpius constellation). Globus is Latin means a small sphere. Globular clusters are found in the halo of galaxies. Open clusters, which contain coming stars (loosely gravitationally bound), are found in the disk of galaxies on the other hand.