Formalhaut b – A planet 25 light years from Earth and is an extreme from our viewpoint, revolves around it’s star Formalhaut and first directly imaged planet at optical wavelength.
N – Nova – An explosion on the surface of a white dwarf that is accreting matter from a companion star, which causes the system to temporarily brighten by a factor of several hundred to several thousand.
(Explanation I found: “small, glassy material formed by the impact of a large body, usually a meteor or asteroid. Tektites are commonly found at the sites of meteor craters”)
D – Denison Olmsted – American physicist and astronomer born in Hartford, Connecticut. He is attributed for founding meteor science. He demonstrated that meteors are cosmic in origin and not an atmospheric phenomenon.