Cistus, with its many hybrids and cultivars, is commonly encountered as a garden flower. The common name rockrose is applied to the species, a name also shared by the related genera Halimium, Helianthemum and Tuberaria, all in the family Cistaceae. The common name gum cistus is applied to resin-bearing species, especially C. ladanifer.
Quasars are part of a class of objects known as active galactic nuclei (AGN). Other classes include Seyfert galaxies and blazars. All three require supermassive black holes to power them.
Quasar actually stands for Quasi-Stellar Radio Source, but thatâs quite a mouthful, so we call them quasars for short. Quasi-Stellar Radio Source also sounds really complex, but when you translate it to simple English, itâs really not. Radio and Source are self-explanatory, but Quasi-Stellar just means star-like.