Johann Bayer used the Greek letters Alpha to Eta to label the most prominent eight stars in the constellation, designating two stars as Delta (named Delta1 and Delta2). John Flamsteed numbered fourteen stars, discerning a third star he named Delta3; his star 12 Canis Minoris was not found subsequently. In Bayers 1603 work Uranometria, Procyon is located on the dogs belly, and Gomeisa on its neck. Gamma Canis Minoris, Epsilon Canis Minoris and Eta Canis Minoris lie nearby, marking the dogs neck, crown and chest respectively. Although it has an apparent magnitude of 4.34, Gamma Canis Minoris is an orange stellar classification giant star of spectral class K3-III C, which lies  away. Its colour is obvious when seen through binoculars. It is a multiple system, consisting of the  spectroscopic binary Gamma A and three optical companions, Gamma B, magnitude 13; Gamma C, magnitude 12; and Gamma D, magnitude 10. The two components of Gamma A orbit each other every 389.2 days, with an eccentric orbit that takes their separation between 2.3 and 1.4 astronomical units (AU). Epsilon Canis Minoris is a yellow bright giant of spectral class G6.5IIb of magnitude of 4.99. It lies  from Earth, with 13 times the diameter and 750 times the luminosity of the Sun. Eta Canis Minoris is a giant of spectral class F0III of magnitude 5.24, which has a yellowish hue when viewed through binoculars as well as a faint companion of magnitude 11.1. Located 4 arcseconds from the primary, the companion star is actually around 440 AU from the main star and takes around 5000 years to orbit it.
How many Delta stars have been designated?
3