The Unarmed Sky-Raiser
Star Name

The Unarmed Sky-Raiser

An asterism of the summer rainy season and the 14th Arab lunar station

Description
السماك الأعزل

Star Names

The Unarmed Sky-Raiser (as-simak al-a’zal)

The Unarmed Sky-Raiser is the lower one of the Two Sky-Raisers (as-simakan). In ancient Arabic, the term simak indicated something that was used to raise something else high up. When the Two Sky-Raisers reached the midpoint of their travels across the night sky, the uppermost one was almost at the zenith, right over your head, and the lower Sky-Raiser was almost directly below it, about halfway up the sky. The Two Sky-Raisers were the pillars that held up the canopy of the heavens. The Unarmed Sky-Raiser is called “unarmed” because it does not have a bright star close to it like the Spear-Bearing Sky-Raiser (as-simak ar-ramih) does.

The Unarmed Sky-Raiser (as-simak al-a'zal) as it appears setting in the west about 45 minutes before sunrise in late April.

The Unarmed Sky-Raiser (as-simak al-a’zal) as it appears setting in the west about 45 minutes before sunrise in late April. Sky simulations made with Stellarium.

Appearance

The southern one of a pair of very bright stars that are spaced widely apart.

Modern Identification

α VIR (Spica), blue-white star, magnitude 1.0

Timing

Ibn Qutayba (d. 879 CE) reported that the Unarmed Sky-Raiser (the first of the pair to set and the second to rise) was said to rise on the morning of October 6 and set on the morning of April 5. On account of the precession of the equinoxes, today we can expect to observe the Unarmed Sky-Raiser setting in late April and rising in late October, as seen from the latitude of Tucson. (See How to Observe on the About page for more on this topic.)

Rain Stars

In the calendars of Qushayr and Qays, the morning settings of the Two Sky-Raisers defined the start and end of the short rainy season of summer (as-sayf).

Lunar Stations

Because the ecliptic (the path of the Moon against the stellar background) passes through the Unarmed Sky-Raiser, within the context of the lunar stations only it, and not the Spear-Bearing Sky-Raiser, had the honor of being a lunar station. In early listings of the lunar stations, the Unarmed Sky-Raiser is the 16th station of the year. This was later changed to the 14th lunar station after the stations were adjusted to begin with the vernal equinox. The star that marks the Unarmed Sky-Raiser matches the Hindu nakshatra called Chitra.

 Related Stars and Celestial Complexes

The Unarmed Sky-Raiser is one of the two primary stars of the Sky-Raisers (as-simakan, السماكان) folkloric celestial complex.

 Related Blog Posts

The Setting of the Arabian Sky-Raisers