## Tibetan (Preliminary)

This is unfinished work and only a tentative solution. Please help us improve! (see below)

During a travel to the Tibetan Autonomous Region of China (TAR) in 2019, I was confronted with a highly complex system of astronomy and calendar computations which has a long tradition in Tibet.

Traditional Tibetan astronomy is largely influenced by the Kalacakra Tantra which has been imported from India, mixed with some Chinese influence.

Emblem on the door sign of Men Tsee Khang institute in Lhasa | Stag Phu observatory Platform. The traditional stone for the shadow observation has been embedded in a concrete platform which shows the lunar mansions. The outermost circle shows figures of the 12 Zodiacal signs (barely visible but enlarged below).

The Men Tsee Khang Institute for Astro and Medicine in Lhasa, TAR, is the central authority for traditional Tibetan medicine and astrology, two fields of research which are closely related in Tibetan tradition. The institute is in charge of editing the annual Tibetan calendar. Although this can be described algorithmically, in 2009 Men Tsee Khang experts have re-erected a calendar observatory in Stag Phu monastery, where a sunrise observation is performed on each March 17th for calibrating the calendar. On this day, just as the sun climbs over a mountain ridge, its first rays are cast through a window in the observatory tower onto a particular rock which has been embedded into a circular platform.

### The Zodiac

The zodiac is partitioned into 12 figures largely identical to the classical figures of the zodiac known in Europe. The following table is from Cornu, with photographs showing the figures illustrated in the circular platform. Note the unexpected appearance of Cancer. Is it a frog?

IAU | Tibetan | Indian | Platform Illustration
--- | --- | --- | ---
<notr> 1</notr> | Ari | Luk | Meṣa |
<notr> 2</notr> | Tau | Lang | Vṛṣa |
<notr> 3</notr> | Gem | Trik | Mithuna |
<notr> 4</notr> | Cnc | Karkata | Karka |
<notr> 5</notr> | Leo | Senge | Simha |
<notr> 6</notr> | Vir | Pumo | Kanyā |
<notr> 7</notr> | Lib | Sangwa | Tulā |
<notr> 8</notr> | Sco | Dikpa | Vṛscika |
<notr> 9</notr> | Sgr | Zhu | Dhanus |
<notr>10</notr> | Cap | Chusin | Makara |
<notr>11</notr> | Aqr | Bumpa | Kumbha |
<notr>12</notr> | Psc | Nya | Mīna |

### The Lunar Mansions

The Men Tsee Khang emblem shows 27 stick figures for the Lunar mansions arranged in a circle around the central figure. The same figures are also laid out in cement with bright stones connected by black lines in the circular platform which has been erected when the observatory was rebuilt. These 27 gyukar figures are described as being equal to the Indian Nakṣatras and represent sections of 13°20' longitude along the ecliptic. Actually, one of the gyukars consists of 2 constellations, therefore 28 lunar constellations are named.

However, not much is known of the exact identification of the Tibetan Lunar Stations outside of Tibet. Most literature is Tibetan or Chinese only, and there were no Tibetan star maps available. Also our guides could not explain any of the following to us.

The following table was taken from Cornu. Note that Tibetans start counting at zero, while the Indians count from 1.

Gyukar | Nakshatra | Stars
--- | --- | ---
<notr> 0</notr> | Takar, Yugu | <notr> 1</notr> | Aśvini | β Ari Sheratan
<notr> 1</notr> | Dranye | <notr> 2</notr> | Bharaṇī | 35 Ari
<notr> 2</notr> | Mindruk | <notr> 3</notr> | Kṛttikā | Pleiades
<notr> 3</notr> | Narma | <notr> 4</notr> | Rohiṇī | α Tau Aldebaran
<notr> 4</notr> | Go | <notr> 5</notr> | Mṛgaśirā | λ Ori
<notr> 5</notr> | Lak | <notr> 6</notr> | Ārdrā | α Ori Betelgeuse
<notr> 6</notr> | Nabso, Gyaltö | <notr> 7</notr> | Punarvasū | β Gem Pollux
<notr> 7</notr> | Gyal, Gyalme | <notr> 8</notr> | Puṣya | 5 Cnc
<notr> 8</notr> | Kak, Wa | <notr> 9</notr> | Aśleṣa | α Hya
<notr> 9</notr> | Chu, Ta chen | <notr>10</notr> | Maghā | α Leo Regulus
<notr>10</notr> | Dre, Ta chung | <notr>11</notr> | Purva-Phālgunī | δ Leo Zosma
<notr>11</notr> | Wo | <notr>12</notr> | Uttara-Phālgunī | β Leo Denebola
<notr>12</notr> | Mezhi | <notr>13</notr> | Hasta | δ Crv Algorab
<notr>13</notr> | Nakpa | <notr>14</notr> | Citrā | α Vir Spica
<notr>14</notr> | Sari | <notr>15</notr> | Svātī | α Boo Arcturus
<notr>15</notr> | Saga | <notr>16</notr> | Viśākhā | α Lib
<notr>16</notr> | Lhatsam | <notr>17</notr> | Anurādhā | δ Sco
<notr>17</notr> | Nrön, Deu | <notr>18</notr> | Jyeṣṭhā | α Sco Antares
<notr>18</notr> | Nup | <notr>19</notr> | Mūla | λ Sco Shaula
<notr>19</notr> | Chutö | <notr>20</notr> | Purvāṣadhā | δ Sgr
<notr>20</notr> | Chume | <notr>21</notr> | Uttarāṣadhā | σ Sgr
<notr>21</notr> | Drozhin + Jizhin | <notr>22</notr> | Uttara-Āṣādhā + Śravaṇa | α Lyr Vega + α Aql Altair
<notr>22</notr> | Möndre | <notr>23</notr> | Dhaniāsṭha | β Del
<notr>23</notr> | Möndru | <notr>24</notr> | Satabhiṣak | λ Aqr
<notr>24</notr> | Trumtö | <notr>25</notr> | Purvabāadrapada | α Peg Markab
<notr>25</notr> | Trume | <notr>26</notr> | Uttarabhādrapada | γ Peg, α And
<notr>26</notr> | Namdru, Shesa | <notr>27</notr> | Revati | σ Psc

The Lunar Mansions in this skyculture are shown as asterisms among the traditional 12 Ptolemaic zodiacal constellations. It is assumed that most originate from the Indian traditions, esp. Kalacakra Tantra, but it appears that some Chinese influence is also present, e.g. Nr. 11. Only for the Zodiacal constellations artwork is provided. A few more constellations in Ptolemaic tradition are displayed in the northern sky to allow easier orientation, but with their names suppressed. We have no information about their names, relevance or even publicity of these in Tibet.

### Please help us

The figures are my own attempt of identification of the Lunar mansion figures. We can be sure about the placement of only those which can also be found in other sky cultures, e.g. Japanese Moon Stations. Many stars are rather dim, and the figures in the emblem apparently have to be rotated in arbitrary ways, like gyukar 3=Hyades. Others require considerable liberties to accept a topological match. Alternative matches with stars in similar topology arranged in the orientation shown in the emblem (north=outer circle) have been found only in neighboring areas of the sky, making a match rather unlikely. Others appear to have been taken over from Chinese tradition, e.g. Nr. 11. LM21 can be explained only if we accept two separate figures which are not joined as shown in the concrete figure. Then they represent Chinese constellations Ox and Girl (which is also Japanese Lunar station Woman).

Alternative figures can be found in the configuration files. We would like to hear from experts of Tibetan astronomy about both confirmed and corrected identification.

#### Further reading

This work accompanies a 3D model of the Stag Phu observatory for use with the Scenery3D plugin and described in:

Georg Zotti, Guntram Hazod, Martin Gamon, Hubert Feiglstorfer: A Calendar Observatory in Tibet. Proc. SEAC2022, Timisoara University Press, 2023. (to appear)

#### Author

Georg Zotti on May 21, 2019, reworked July-October 2023.