Hindu civilization is the only one with a memory of two pole starts. This thread will talk about the ancient memory of Dhruva.
Dhruva was the son of king Uttanapada who was slighted by his step mother for sitting on the lap of his father. He then goes to the forest to do...(1/n)

...penance on the advice of his mother Suniti, where God Vishnu appears & gives him a boon that after his life on earth he will stay near (Vishnu) as Dhruva the fixed Pole star. This story is traced to the Brahmanda, Vishnu Purana & other Puranas with slight variations...(2/n)

However, the current Pole Star α-Ursa Minor (Polaris) we see in sky today is not the Dhruva of the Puranic and Vedic texts. Modern Astronomy tells us that Polaris became the Pole start only around 1600 CE, prior to that there was no fixed star at the north Celestial pole...(3/n)

The Puranas are generally believed to be composed roughly between 500 BCE and 500 CE, but the information contained in these Puranas is much older going back several millennia. Earlier to the Puranas, Dhruva finds mention as a star in the Mahabharata and Vedic texts....(4/n)

To understand why the star located at the North Celestial pole changes, we need to understand the phenomena of precession. Earth is tilted at an angle of 23.5 degrees and the tilt direction keeps changing & the geographic north pole creates a circle after each full cycle....(5/n)

.....of ~27000 years. Several stars lie on this circular path including the current Pole star α-Ursa Minor, but in 3000 BCE Thuban or α-Draconis was at the position of the North pole....(6/n)

Taittiriya Aranyaka 2.19 describes a celestial animal called Shishumaara (Dolphin or Whale) whose body is made of 14 stars and the tail-end is the Dhruva.
1) Head: Dharma
2) Upper Jaw: Brahma
3) Lower Jaw: Yajna
4) Heart: Vishnu
5) Genital: Samvatsara

......(7/n)

6,7) Forelegs: Ashwin twins
8) Naval: Atri
9,10) Hind legs: Mitra & Varuna
11) Tail -1: Agni
12) Tain-2: Indra
13) Tail-3: Prajapati
14) Tail end: Abhaya Dhruva

....(8/n)

In later vedic texts like the Maitrayani Aranyaka mention that Dhruva was moving and not fixed anymore, this period could be around ~1600 BCE.
Vriddhagargiya Jyotisha (800-300 BCE) also mentions the Dhruva rotating and no longer fixed......(9/n)

Al Biruni (973-1048 CE) in his books on India mentions that the Hindus believe in a fixed Pole star which in the tail of Shishumara, which the Persians called Shishmara a form of Lizard. Current Pole star in Ursa Minoris called Dhruva Matsys (Fish) in Sanskrit... (10/n)

Adi Shankaracharya in his commentary on Vishnu Sahasranama mentions the Dhruva star in Shishumara nakshatra. Same belief was accepted by Ramanujacharaya and Madhwacharya, showing that traditional Vedic scholars still remembered the older Pole star from 3000 BCE...(11/n)

.....even though it had moved away from its original position long ago.
Hindus have preserved memory of an astronomical motif from many thousands ago. Also shows that the dates of composition of Vedic texts goes back to 2nd or 3rd millennia BCE. (12/end)

All info sourced from Prof RN. Iyengars lectures and research papers.