Satabhisa
शतभिषक्/शततारका (Sanscrit for Satabhisa) is the 24th of the 27 Nakshatras. Spelling variants are Śatabhiṣa, (Śatabhiṣaj; Śatabhiṣak).
Etymology and History
The system of nakshatras for marking the path of the moon (and the sun) has been prevalent for almost 5000 years since the epics and older texts on astronomy mention the 27 asterisms with their determinative stars.
Etymology of the name
This nakshatra consists of four stars but the name consisting of the term "sata" for "100" led to the misinterpretation that there were one hundred stars. The earliest identification of 100 stars by Varahamihira of 7th century has been carried forward.[1] The works prior to that refer to it as one to four star(s), [1] see table on p. 344. Because of this misinterpretation, the asterism is sometimes referred to as śatatārā (meaning 100 stars).
The word's literal meaning is ‘100 physicians’ (p. 346) – the origin is unknown.[1]
Main Star
The star λ Aquarii is considered the determinative star of the nakshatra.[1] Alternatively, in particular in mantic circles, alternatively γ Aqr is used (probably a reading or writing error). The identification with λ Aqr with Śatabhiṣa can be traced to the early works of Colebrook, Bentley, Whitney and Burgess, corroborated by Indian authors who were well versed with Siddhanta and European astronomy; they include Keropant, Bapudeva Sastry, V B Ketkar and S B Dikshit (all scholars of 19th century). We checked the coordinates from the catalogue of Nityananda (15th century) and they match: There are no star maps with the names written down. The only chart that is available in Jaipur collection was prepared by Madho Singh (son of Sawai Jai Singh, who built the famous masonry instruments). It is a chart (T006, online catalogue of Sarma, 2023[2]) for identifying the time of meridian transits of stars. The red pointers give the transit time; the black ones provide rise and times. From the chart we can read 56:32 ghaṭi for Śatabhiṣa. We need to understand this in the Indian system, which has a day is divided into 60 ghaṭi. On this scale for example, the meridian transit of Antares (Jyeṣṭha) occurs at 40:34 as per the Table. The difference 15:58 ghaṭi gets converted to 6h 23min (with 1 ghaṭi = 24 minutes). This is exactly the difference in their Right Ascensions, 22:52 - 16:29 = 6:23 (from stellarium).
In India, "nakshatras" are used to mark the movement of the moon. The path of the moon is visible in the sky as the moon occasionally covers stars in this rage of 5° around the ecliptic. λ Aquarii is directly at the ecliptic and therefore cannot only be covered by the moon but also by the planets which makes the star's position particularly interesting.
Modern India
In modern Indian planetariums and popular astronomy, the name Satabhisa is used for the star λ Aquarii (that stands pars pro toto for the nakshatra).
Mythology
There is a mantic meaning of all nakshatras. Each of them is ruled by a planet and a deity. The "Lord" of Satabhisa is the north lunar node (Rahu), the deity is Varuna, the god of cosmic waters, sky and Earth. The nakshatra covers the section of the zodiac 13° 46 to 27°06 Pisces (which now lays in the constellation of Aquarius due to precession).
IAU Working Group Star Names
The name was discussed and approved by the IAU WGSN in 2024. As this star is already named ..., the WGSN chose ... (not to apply/ to apply the name to a neighbouring star/ to ...) in the IAU-CSN.
Reference
- https://archive.org/details/BharatiyaJyotishSastra2
- Sarma, S.R., 2023. A descriptive catalogue of Indian Astronomical Instruments MS https://srsarma.in/catalogue.php
