Update: The 11th century astrolabe sold for more than $781,000.

What you see: A rare Umayyad-era brass astrolabe, signed by Muhammad ibn al-Saffar and dated in Western Abjad 411 AH (1020 AD). It is the earliest known dated astrolabe from Muslim Spain. It comes from a French collection. Sotheby’s estimates it at £300,000 to £500,000, or $372,900 to $621,000.

What is an astrolabe? “Basically, it’s an ancient astronomical computer,” says Benedict Carter, head of auction sales of Middle East and Indian art at Sotheby’s. “It’s a two-dimensional representation of a three-dimensional celestial sphere. Typical uses were for finding the time during the day or night, and figuring out the times of sunrise or sunset.”

What makes this astrolabe special? “It’s a thousand-year-old astrolabe, and it’s very rare as it’s signed and dated,” he says. “This period [between the ninth and fourteenth centuries] has an awful lot of enthusiasm for it, not just from collectors from the Middle East. Buyers and collectors globally want to buy into the achievements of the Islamic Golden Age.”

Who would have used this astrolabe? “It was probably a princely commission. A lot of time went into making it,” Carter says, noting that it is the first of three signed astrolabes produced by Muhammad ibn al-Saffar over the course of 10 years. “It was a very niche, courtly thing. Not just any old person would have one. That’s why there’s not so many out there, and most are in museums.”

Is it entirely original? No. The pierced face of the astrolabe, which is known as a rete, was replaced in Turkey sometime in the 16th or 17th centuries. “It is a functional replacement,” Carter says. “Five hundred years after it was made, it was a valuable tool, still being used. That tells us a lot.”

How soon did you know that you had something special with this? “The moment I saw this, I knew it was pretty exciting,” he says. “I didn’t know it was signed or dated, but I immediately realized it looked early and important. You always hope something like this will show up, and one day, it does.”

How to bid: The astrolabe is lot 170 in Sotheby’s Arts of the Islamic World auction, which takes place in London on April 26, 2017.

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Text is copyright Sheila Gibson Stoodley. Image is courtesy of Sotheby’s.

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