Dhanusaragra: Difference between revisions
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The term ''Dhanuśarāgra (धनुशराग्र)'' literally means tip of the arrow. ''Dhanu'' - bow, ''śara'' - arrow, ''agra'' - tip. It agrees with the position corresponding to the tip of the arrow. There are two stars γ1 and γ2, shown inside the red circle in the diagram. Although the original diagram responsible for the nomenclature is not traceable, the depiction here supports the etymology of the name . | The term ''Dhanuśarāgra (धनुशराग्र)'' literally means tip of the arrow. ''Dhanu'' - bow, ''śara'' - arrow, ''agra'' - tip. It agrees with the position corresponding to the tip of the arrow. There are two stars γ1 and γ2, shown inside the red circle in the diagram. Although the original diagram responsible for the nomenclature is not traceable, the depiction here supports the etymology of the name . | ||
This star name thus can be for γ1 | This star name thus can be for γ1 Sagittarii. | ||
== Transfer and Transformation == | == Transfer and Transformation == | ||
This name has been found in the catalogue of astrolabes translated from Persian. The | This name has been found in the catalogue of astrolabes translated from Persian. The name has been coined as shown in the two examples below. <ref>Sarma S R, 2023, A Descriptive Catalogue of Indian Astronomical Instruments, https://srsarma.in/catalogue.php </ref> | ||
The astrolabes were introduced in to Indian astronomy by sea farers from the Middle East. In the first manual prepared by Mahendra Suri in the 1370CE only 32 bright stars were listed. Subsequently other faint stars also were marked. Based on the original data, the stars names were literally translated in most of the cases. The name is listed in the earliest manual by Mahendra Suri as the 26th star. It may be seen that there was no Persian name for | The astrolabes were introduced in to Indian astronomy by sea farers from the Middle East. In the first manual prepared by Mahendra Suri in the 1370CE only 32 bright stars were listed. Subsequently other faint stars also were marked. Based on the original data, the stars names were literally translated in most of the cases. The name is listed in the earliest manual by Mahendra Suri as the 26th star. It may be seen that there was no Persian name for ''Dhanuśarāgra'' . Therefore, this must have been coined to suit the imaginary picture. | ||
[[File:Yantrarajaname.jpg|alt=Number 26 for this star and 27 for Vega|thumb|The list from Mahendra Suri (1370CE) assigns number 26 ]] | [[File:Yantrarajaname.jpg|alt=Number 26 for this star and 27 for Vega|thumb|The list from Mahendra Suri (1370CE) assigns number 26 ]] | ||
In the astrolabe C006 (1644CE) made by Maniarama from Gujarat, India, the stars are marked with two letter abbreviations and the numeral corresponding to the list of Mahendra Suri. Dhanu 26 on the rete, therefore, will correspond to ''Dhanuśarāgra'' . The identification was done by stars overlay on the rete. | |||
The close up view here shows the pointer on the rete. Using Spica (S) and Altair (A) as references, we see that the pointer is for a different star in Ophiucus.[[File:Closeup view of the region showing number 26 and 27.jpg|alt=Number 26 and 27 are marked on the rete|thumb|Close up of the region showing numbers 26 Dhanu and 27 ]] | |||
[[File:Closeup view of the region showing number 26 and 27.jpg|alt=Number 26 and 27 are marked on the rete|thumb|Close up of the region showing numbers 26 Dhanu and 27 ]] | |||
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[[File:Dhanusragraidentification.jpg|alt=Identification with the help of Spica (S) and Altair (A) as reference|thumb|Stars overlay on the rete; reference stars are Altair (A) and Spica (S)]] | [[File:Dhanusragraidentification.jpg|alt=Identification with the help of Spica (S) and Altair (A) as reference|thumb|Stars overlay on the rete; reference stars are Altair (A) and Spica (S)]] | ||
C001 in the catalogue was prepared by Damodara of Ahmedabad in 1605. The engraving on the dial reads | |||
C001 in the catalogue was prepared by Damodara of Ahmedabad in 1605. The engraving on the dial reads ''Dhanuśirā'' ;this is μ Sgr. The catalogue reports ''Dhanuśarāgra'' as a correction. This is a curious case of mis-identification. The position on the rete matches with neither with ''Dhanuśira'' (μ Sgr) nor ''Dhanuśarāgra'' (γ Sgr). However, this brings out the information that these two star names were in use.. | |||
The position actually corresponds to the supernova of 1604 CE. <ref>Shylaja B S, 2019, Records of Supernovae, Current Science, 116, 1430</ref> <ref>Shylaja B S, 2026, Astrolabes as records of previous eruptions of recurrent nova T CrB, 47, 39</ref> | |||
[[File:It is the close up view of rete of C001 .jpg|alt=C001 with pointer for Dhanusharagra |thumb|The region of Dhanusharagra in C001 shows the pointer to the location of the SN1604]] | [[File:It is the close up view of rete of C001 .jpg|alt=C001 with pointer for Dhanusharagra |thumb|The region of Dhanusharagra in C001 shows the pointer to the location of the SN1604]] | ||
[[File:Dhanusaragra misidentification.jpg|alt=The catalogue shows that the star was misread and identifies it with mu Sgr|thumb|This table shows that the star was misidentified as mu Sgr in the catalogue]] | [[File:Dhanusaragra misidentification.jpg|alt=The catalogue shows that the star was misread and identifies it with mu Sgr|thumb|This table shows that the star was misidentified as mu Sgr in the catalogue]] | ||
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The accuracy of the star dials cannot distinguish between the two stars | The accuracy of the star dials cannot distinguish between the two stars γ1 and γ2. Therefore ''Dhanuśarāgra'' is proposed for γ1 which now has no names ( W Sgr form the variable star catalogue).<gallery> | ||
</gallery> | </gallery> | ||
Revision as of 11:19, 28 July 2026
Authors: Shylaja, Susanne M Hoffmann, ASE Tech Team, IanRidpath
...
Etymology and History
Name Variants
- Dhanuśarāgra (धनुशराग्र)
- Dhanusharagra
Origin of Constellation
The term Dhanuśarāgra (धनुशराग्र) literally means tip of the arrow. Dhanu - bow, śara - arrow, agra - tip. It agrees with the position corresponding to the tip of the arrow. There are two stars γ1 and γ2, shown inside the red circle in the diagram. Although the original diagram responsible for the nomenclature is not traceable, the depiction here supports the etymology of the name .
This star name thus can be for γ1 Sagittarii.
Transfer and Transformation
This name has been found in the catalogue of astrolabes translated from Persian. The name has been coined as shown in the two examples below. [2]
The astrolabes were introduced in to Indian astronomy by sea farers from the Middle East. In the first manual prepared by Mahendra Suri in the 1370CE only 32 bright stars were listed. Subsequently other faint stars also were marked. Based on the original data, the stars names were literally translated in most of the cases. The name is listed in the earliest manual by Mahendra Suri as the 26th star. It may be seen that there was no Persian name for Dhanuśarāgra . Therefore, this must have been coined to suit the imaginary picture.
In the astrolabe C006 (1644CE) made by Maniarama from Gujarat, India, the stars are marked with two letter abbreviations and the numeral corresponding to the list of Mahendra Suri. Dhanu 26 on the rete, therefore, will correspond to Dhanuśarāgra . The identification was done by stars overlay on the rete.
The close up view here shows the pointer on the rete. Using Spica (S) and Altair (A) as references, we see that the pointer is for a different star in Ophiucus.
C001 in the catalogue was prepared by Damodara of Ahmedabad in 1605. The engraving on the dial reads Dhanuśirā ;this is μ Sgr. The catalogue reports Dhanuśarāgra as a correction. This is a curious case of mis-identification. The position on the rete matches with neither with Dhanuśira (μ Sgr) nor Dhanuśarāgra (γ Sgr). However, this brings out the information that these two star names were in use..
The position actually corresponds to the supernova of 1604 CE. [3] [4]
The accuracy of the star dials cannot distinguish between the two stars γ1 and γ2. Therefore Dhanuśarāgra is proposed for γ1 which now has no names ( W Sgr form the variable star catalogue).
Mythology
Weblinks
References
- ↑ https://upload.wikimedia.org/wikipedia/commons/7/7e/Sidney_Hall_-_Urania%27s_Mirror_-_Sagittarius_and_Corona_Australis%2C_Microscopium%2C_and_Telescopium.png
- ↑ Sarma S R, 2023, A Descriptive Catalogue of Indian Astronomical Instruments, https://srsarma.in/catalogue.php
- ↑ Shylaja B S, 2019, Records of Supernovae, Current Science, 116, 1430
- ↑ Shylaja B S, 2026, Astrolabes as records of previous eruptions of recurrent nova T CrB, 47, 39
