The Aui.
The Aui (symbol: Λ) is the currency of the Sirian Union. 100 Aur make 1 Aui. Distinguishing between Aui and Aur is done via the position of the Λ symbol. For example, Λ1 is 1 Aui, but 1Λ is 1 Aur. The Aui symbol was selected by the Sirian Federal Treasury after a lengthy debate and national competition in 2926 because of its resemblance to the famous "three chevrons" of the Sirian Union's flag. It was felt that this would both encourage national pride and be easy to recognise and write. However, because of the vastness of Sirian space (and the fact that a major civil war had just concluded) it took several months for the new currency to be adopted wholesale.
In the meantime, the old warlord currencies were still used, but treated as though they were Aui rather than their 'original' currency. However, they were steadily removed from circulation via an exchange programme, resulting in the eventual eradication of Warring Kingdoms Period coinage from circulation over the same period. They are highly prized as collectors' items.
Commemorative coinage is occasionally produced in the Sirian Union, normally to honour a significant event (such as a major military victory or the passing of an influential Sirian person). Furthermore, although the Aui is a digital currency, if necessary it may be converted into physical currency (for example, as a result of issues with the digital system). Both coins include a polymer ring set into them that glows. This is a security measure, and the ring may hold any sort of colour pigmentation, though blue, red and white are the most popular. The ring may also change colour under certain conditions, for example if exposed to UV light. The "heads" of an Aui coin has the Λ symbol, whilst the opposite side usually has an image of an important Sirian or a location in the Sirian Union. The design is usually very intricate. On the Λ1 and Λ2 coins the motto of the Sirian Union is inscribed around the rim, though other coinage may instead have quotations or other mottos inscribed on them (for example, a planetary motto).
The Aui has relatively simple denominations; coins consist of 1Λ, 2Λ, 5Λ, 10Λ, 20Λ, 50Λ, Λ1, and Λ2 coins. Λ5, Λ10, Λ20, Λ50, and Λ100 notes are available.