Ancient Astronomy

Indian astronomy is very ancient as we know. It is assumed that there were no sophisticated instruments available during that time. Today's astronomers are much more powered by advent of technology.

Measuring a position of a star in sky or measuring it's luminosity is a simple thing. But since stars are many light years away from us predicting their size, temperature or distance from solar system is really a tough task. Todays astronomers can do that because of sophisticated angular measurments, spectrometers etc. The distances of the stars are measured using various methods, of which, 'parallax' is most accurate method. Measuring parallax requires high precision angular measurement. The size of stars is determined by their characteristic spectrum and their distance from solar system. So they need spectrometers. Were these instruments present in ancient time ? Probably not !

Today we know that Alpha Centauri is the closest star to our solar system. It is around 4.37 light years from us. This star is known as "Mitra" (friend) in Indian Astronomy. The star "Antares" is one of the super-giant stars in our galaxy. It is about 800 times larger than sun. This star is known as "Jyeshtha" (eldest or largest) in Indian system. It's quite amazing that how come these names match the actual facts ? Is it just a coincidence ? If we assume that our sages did not had any sophisticated instruments and if technology was not developed that time then how could they know that Mitra is closest to us and Jyeshtha is a giant star ?