czsky/en/star/hr4825.md

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---
name: Porrima (γ Virginis)
constellation: Vir
created_by: editor.cs
created_date: 2023-11-05 16:30:55.633696
updated_by: editor.cs
updated_date: 2023-11-05 16:30:55.633700
---
One of the most beautiful double stars in the sky, both yellow-white components have almost the same brightness of 3.5 magnitude and can be observed with a 6 cm telescope at a separation of 3". Their orbital period around the common center of mass is 171.85 years. The largest separation was reached in 1920 - 6.2", so they could be distinguished even with a 5 cm telescope. Meanwhile, their mutual distance is rapidly decreasing. In 1985, the value reached 3.5", in 2000 only 1.8". Therefore, currently we need at least a 200 mm telescope to distinguish the two point-like stars under good seeing conditions. In 2007, the separation will be even smaller, only 0.3", and therefore we will need a significantly larger telescope to resolve them. The system is located 32 light-years away from us. Five arc degrees to the north lies the brightest quasar - thirteenth magnitude, labeled 3 C 273, located approximately 3 billion light-years away.