Śaṅkaranārāyaṇa

Sankaranarayana (c. 840 – c. 900 AD) was an Indian astronomer-mathematician in the court of Sthanu Ravi Kulasekhara (c. 844 – c. 870 AD) of the early medieval Chera kingdom in Kerala. He is celebrated as the author of Laghubhaskariyavivarana or Laghubhaskariyavyakha, a detailed commentary on astronomical treatise Laghubhaskariya by 7th century mathematician Bhaskara I (which in turn was based on the works of the 5th century polymath Aryabhata).

Sankaranarayana is known to have established an astronomical observatory at the port of Mahodayapuram, present-day Kodungallur, in central Kerala. Laghubhaskariyavivarana (Chapter VII) explicitly states that it was composed in Saka Year 791 (corresponding to 869/70 AD). In the second verse of the commentary Sankaranarayana remembers five major predecessors in the field of mathematics (Aryabhata, Varahamihira, Bhaskara I, Govinda and Haridatta), including his possible master Govinda (c. 800 – c. 860 AD).

The commentary notably mentions an expert astronomer who had travelled to the mleccha country.