Ascella

Authors: IAU-WGSN Etymology Group, Roland Laffitte, Susanne M Hoffmann, Youla Azkarrula, IanRidpath

---

Ascella (إبط) is a modern star name adopted by the International Astronomical Union in the IAU-Catalog of Star Names (IAU-CSN). Its origin is Latin. It is the name of HIP 93506 (ζ Sgr, HR 7194) in constellation Sgr.

Etymology and History

Ascella is a Latin word meaning "armpit". Although it appeared in the 1515 Almagest, the name does not appear to have come into common usage until the 20th century after appearing as Ascella in Richard Hinckley Allen's "Star Names Their Lore and Meaning" (1899).

Error creating thumbnail: Unable to save thumbnail to destination

Sagittarius with Arabic star names (CC BY Laffitte 2025).

Roland Laffitte (2025)

Calque de l’arabe ibṭ employé dans l’Almageste pour décrire la situation de cette étoile, il a vite été employé comme nom, et il est aujourd’hui approuvé par l’UAI. Gr. μασχάλη / maskhalē, « aisselle », Ptolémée > ibṭ, « idem », al-Ḥağğāğ > ‘ascella’, « idem », Gérard de Crémone ; ‘axela’, Bayer, d’où Ascella, Allen, puis Rumrill, etc., Simbad, UAI.

AUTRE NOM : Alsadira Tertia. Ar. الصادرة [النعايم] [al-Na^cā’im] al-Ṣādira p/ le goupe ζστφ Sgr ; pour les explications, se reporter à φ Sgr. Quant à ζ Sgr, nous avons, via M. A. Sédillot, Aldadira Tertia, Benhamouda, mais abs. c/ Knobel. Thalith al Sadira, Wiki.

English:

A loanword from the Arabic ibṭ, used in the *Almagest* to describe the position of this star, it was quickly adopted as a name and is now approved by the IAU. Gr. μασχάλη / maskhalē, “armpit,” Ptolemy > ibṭ, “same,” al-Ḥağğāğ > ‘ascella’, “same,” Gerard of Cremona; ‘axela’, Bayer, hence Ascella, Allen, then Rumrill, etc., Simbad, IAU.

OTHER NAME: Alsadira Tertia. Arabic: الصادرة [النعايم] [al-Nacā’im] al-Ṣādira for the group ζστφ Sgr; for explanations, see φ Sgr. As for ζ Sgr, we have, via M. A. Sédillot, Aldadira Tertia, Benhamouda, but absent in Knobel. Thalith al Sadira, Wiki.

IAU Working Group on Star Names

The name was adopted by the IAU WGSN on 2016/09/12.

Weblinks

• Website of the IAU WGSN: https://exopla.net/

Reference

• References (general)
• Ptolemaeus. (1515). Almagestū Cl[audii] Ptolemei Pheludiensis Alexandrini Astronomo[rum] principis : opus ingens ac nobile omnes celorū motus continens ... Liechtenstein, Petrus. p.84.