- A phanerite is an igneous rock whose microstructure is made up of crystals large enough to be distinguished with the unaided human eye. In contrast, the crystals in an aphanitic rock are too fine-grained to be identifiable. Phaneritic texture forms when magma deep underground in the plutonic environment cools slowly, giving the crystals time to grow.
- Iota-1 Scorpii (stars.astro.illinois.edu)
IOTA-1 SCO (Iota-1 Scorpii). Supergiants are rare, and to find two of them within a quarter-degree of each other is rarer still. To find two forms of supergiants that for the class are rare in themselves draws the eye, or at least should. Nevertheless, these two magnificent stars, which have no proper names and are known as Iota-1 (the western and brighter) and Iota-2 Scorpii, are quite neglected, perhaps by contrast to Scorpius’s brighter magnificent stars, which include one of the most prominent of all supergiants, Antares.