- Cathetus (Wikipedia)
In a right triangle, a cathetus (originally from the Greek word Κάθετος; plural: catheti), commonly known as a leg, is either of the sides that are adjacent to the right angle. It is occasionally called a “side about the right angle”. The side opposite the right angle is the hypotenuse. In the context of the hypotenuse, the catheti are sometimes referred to simply as “the other two sides”.
- NGC 7662 (Wikipedia)
NGC 7662 is a planetary nebula located in the northern constellation Andromeda. It is known as the Blue Snowball Nebula, Snowball Nebula, and Caldwell 22. This nebula was discovered October 6, 1784 by the German-born English astronomer William Herschel. In the New General Catalogue it is described as a “magnificent planetary or annular nebula, very bright, pretty small in angular size, round, blue, variable nucleus”. The object has an apparent visual magnitude of 8.3 and spans an angular size of 32″ × 28″. Parallax measurements give a distance estimate of 5,730 ± 340 ly (1,757 ± 103 pc).
