Dhanuśarāgra (धनुशराग्र)

Not to be confused with Dhanuśira (धनुशिर).

Authors: Shylaja, Susanne M Hoffmann, ASE Tech Team, IanRidpath

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The list from Mahendra Suri (1370CE) assigns number 26 for Dhanuśarāgra . It is not based on any original name.

Dhanuśarāgra

Asterism Info
Native	धनुशराग्र
Translation	The Arrow
Position (2000)
Right ascension	271.2551101
Declination	-29.58008951
Area	0 sq. deg.
Stars
Bright stars	1
Bayer/Flamsteed stars	1
Stars brighter than 3.00m	0
Brightest star	Dhanuśarāgra (4.69m)
Taxonomy
category of asterism	IAU-Star Name
IAU- constellations	Sgr

Stars overlay on the rete of C006; reference stars are Altair (A) and Spica (S). The red circle is the pointer for Dhanuśarāgra -– it appears to be for some star in Ophiuchus.

Dhanuśarāgra (धनुशराग्र), The Arrow, is an Indian star name found in the recent few centuries (starting from the 14th century CE) for a star in Sagittarius. It is obviously a translation of a Greek name or a Sanskrit name for a feature in the imported Greek constellation figure. Note that is star name is occasionally mixed up with the star name Dhanuśira (धनुशिर) for μ Sgr in the Bow.

Concordance, Etymology and History

The term Dhanuśarāgra (धनुशराग्र) literally means tip of the arrow. Dhanu - bow, śara - arrow, agra - tip.

Name Variants

• Dhanuśarāgra (धनुशराग्र)
• Dhanusharagra

Origin of Constellation

The star name is found on instruments. Although the original diagram responsible for the nomenclature is not traceable, the depiction here supports the meaning (arrow tip) of the name.

The position on the astrolabe agrees with the position corresponding to the tip of the arrow. There are two stars γ¹ and γ² Sgr, shown inside the red circle in the diagram. This star name thus can be for γ¹ Sagittarii. (W Sagittarii, HR 6742, HD 164975, SAO 186237, HIP 88567, ADS 11029, CCDM 18050-2935)

Concordance

This table shows that the star was misidentified as μ Sgr in the catalogue

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.

The astrolabes were introduced into Indian astronomy by seafarers from the Middle East. In the earliest manual prepared by Mahendra Suri in the 1370 CE, only 32 bright stars were listed. Subsequently, other faint stars were also marked. Based on the original data, the star names were literally translated in most of the cases. The name is listed in the 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.

Astrolabe C006 (1644 CE)

In the astrolabe C006 (1644 CE) 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 Ophiuchus. It is possible that the engraved number is in error.

Astrolabe C001 (1605)

C001 in the catalogue was prepared by Damodara of Ahmedabad, India, 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 misidentification. The position on the rete matches with neither with Dhanuśira (μ Sgr) nor Dhanuśarāgra (γ Sgr). However, this brings out the important information that the star name Dhanuśarāgra was in use.

The position actually corresponds to the supernova of 1604 CE.

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 name (W Sgr form the variable star catalogue).

Transfer and Transformation

• 
  Stars overlay on the rete of C006; reference stars are Altair (A) and Spica (S). The red circle is the pointer for Dhanuśarāgra – it appears to be for some star in Ophiuchus.
• 
  Close up of the region in C006 showing numbers 26 Dhanu and 27.
• 
  The region of Dhanuśarāgra in C001 with stars overlay shows the pointer to the location of the SN1604 with both μ Sgr and γ Sgr far from it.
• 
  This table shows that the star was misidentified as μ Sgr in the catalogue

Mythology

Dhanuśarāgra is in the red circle surrounding the stars γ¹ and γ². The other circle is for μ Sgr. These two are marked on the image from Urania's Mirror and Shylaja, wikicommons

References

• References (general)