Tibetan moon houses

The Tibetan division of the ecliptic into 12 signs of the zodiac (red) and 27 lunar houses (blue)

The 27 Tibetan lunar houses ( Tib . : rgyu skar , "stars on which one walks") result from the division of the ecliptic into 27 equal parts and thus form an angular measure of Tibetan astronomy , which is generally used to calculate the lengths of the sun and moon , the planet known in Tibet and the comet Encke was used. For astronomical calculations these moon houses are counted with the numbers 0 to 26. In addition, the division of the ecliptic into 12 signs of the zodiac was known in Tibet .

This division of the ecliptic into lunar houses, which was known in Tibet since the 8th century and was used there for astronomical calculations since the translation of the Kālacakratantra in the 11th century, was adopted by the Tibetans from India, where the lunar houses were called Nakşatra .

The basis of the division into 27 parts was the fact that the moon naturally needs a little more than 27 days for a sidereal orbit , i.e. it stays in a different lunar house every day.

The division into lunar houses in Tibet is closely related to the idea that the lunar houses correspond to certain constellations . B. in the 1685 written Vaiḍūrya dkar-po of the regent Desi Sanggye Gyatsho has been described.

Furthermore, the moon houses in Tibet, as well as the planets, were identified with certain gods.

In addition, the Tibetans were aware of the division of the ecliptic into 28 lunar houses, which, although it played no role in the computational astronomy of the Tibetans, was used in particular in the Sinotibetic divination calculations (Tib .: nag rtsis ). The latter assigned certain elements and directions to the lunar houses for divinatory calculations , a procedure that was adopted by the Tibetans from China. As the 28th moon house, the moon house byi ha zhin or byi bzhin ( Sanskrit : Abhijit), also known in India, was inserted between the moon houses gro bzhin and mon gre .

List of Tibetan moon houses

count	Tibetan name	Constellation (description) according to Vaiḍūrya dkar-po	Element of nag-rtsis	Cardinal direction of the nag-rtsis
0	tha skar	Consists of three main stars with the shape of a horse's head and neck (Tib .: rta mgo mgul )	water	north
1	bra nye	Consists of three main stars that have the shape of a woman's genitals (Tib .: mo mtshan ).	earth	North-west
2	smin drug	Consists of six main stars that are shaped like a razor (Tib .: spu gri ).	Wood	east
3	snar ma	Consists of five main stars in the shape of a chariot (Tib .: shing rta ).	Wood	east
4th	mgo	Consists of three main stars that have the shape of the head of a deer (Tib .: ri dvags mgo ).	Wood	east
5	lay	Consists of a main star that has the shape of a round point (Tib .: thig le ).	Wood	east
6th	nabs so	Consists of two main stars shaped like the foot of a throne (Tib .: khri rkang ).	Wood	east
7th	rgyal	Consists of three main stars that have the shape of a drop (Tib .: ril ba ).	Wood	east
8th	skag	Consists of six main stars that have the shape of a distended snake neck (Tib .: gdengs ka ).	earth	southeast
9	mchu	Consists of six main stars that have the shape of a river (Tib .: chu bo ).	Fire	south
10	gre	Consists of two main stars that have the shape of a human leg (Tib .: mi rkang ).	Fire	south
11	dbo	Consists of two main stars that have the shape of a throne (Tib .: khri ).	Fire	south
12	me bzhi	Consists of five main stars that are shaped like a hand (Tib .: lag ).	Fire	south
13	nag	Consists of a main star that has the shape of the lotus fruit (Tib .: pad snying ).	Fire	south
14th	sa ri	Consists of a main star that has the shape of a gemstone (Tib .: nor bu ).	Fire	south
15th	sa ga	Consists of four main stars in the shape of a goat's head (Tib .: ra mgo ).	earth	Southwest
16	lha mtshams	Consists of four main stars that have the shape of a bull (Tib .: glang po ).	iron	west
17th	snron	Consists of three main stars that have the shape of a ladder (tib .: them skas ).	iron	west
18th	snrubs	Consists of nine main stars that have the shape of a scorpion (Tib .: sdig pa ).	iron	west
19th	chu stod	Consists of four main stars that have the shape of a stupa (Tib .: mchod rten ).	iron	west
20th	chu smad	Consists of four main stars that have the shape of a Bre meter (Tib .: bre ).	iron	west
21st	big bzhin	Consists of three main stars that have the shape of a Bre measuring device (Tib .: bre ).	iron	west
[21a]	byi bzhin	Consists of three main stars that have the shape of a cow's head (Tib .: glang mgo ).	earth	North-west
22nd	mon gre	Consists of four main stars that have the shape of a bird (Tib .: bya ).	water	north
23	mon gru	Consists of two main stars that have the shape of a bouquet of flowers (Tib .: me tog phung ).	water	north
24	khrums stod	Consists of two main stars in the shape of a chariot (Tib .: shing rta ).	water	north
25th	khrums smad	Consists of two main stars that are shaped like an ear (Tib .: rna ba ).	water	north
26th	nam gru	Consists of thirty-two main stars in the shape of a boat (Tib .: gru ).	water	north

swell

sde-srid Sangs-rgyas rgya-mtsho: Phug-lugs rtsis kyi legs-bshad mkhas-pa'i mgul-rgyan vaidur dkar-po'i do-shal dpyod-ldan snying-nor (block print)
Winfried Petri: Indo-Tibetan Astronomy. Habilitation thesis to obtain the venia legendi for the subject history of natural sciences at the high natural sciences faculty of the Ludwig Maximilians University in Munich . Munich 1966
Dieter Schuh: Studies on the history of the Tibetan calendar calculation . Wiesbaden 1973
Te-ming Tseng: Sino-Tibetan divination calculations (Nag-rtsis) presented using the work dPag-bsam ljon-šing by Blo-bzang tshul-khrims rgya-mtsho . International Institute for Tibetan and Buddhist Studies, Halle 2005. ISBN 3-88280-070-4