Which one of the following does not find mention in the works of the astronomers of ancient India?

Ancient Indian astronomers, such as Aryabhata and Varahamihira, recognized the Navagrahas (nine celestial bodies). These included the Sun (Surya), the Moon (Chandra), and the five planets visible to the naked eye: Mercury (Budha), Venus (Shukra), Mars (Mangala), Jupiter (Brihaspati), and Saturn (Shani). The lunar nodes, Rahu and Ketu, were also part of this system. Uranus is not visible to the naked eye and was only discovered in 1781 by William Herschel using a telescope. Consequently, it does not find mention in ancient Indian astronomical treatises like the Surya Siddhanta or the Aryabhatiya, which were based on naked-eye observations.