Astronomical ABCD...! Today, I thought to make a list of Astronomical objects, A to Z. 

It goes as follows :


A - Asteroid
B - Black Hole
C - Comet
D - Dwarf Planet
E - Elliptical Galaxy
F - Falling Star
G - Globular Cluster
H - Hypergiants (Stars)
I - Interstellar Medium
J - Jets (Astrophysical)
K -  $\color{red} ?$
L - Lenticular Galaxy
M - Meteor
N - Nebula
O - Open Cluster
P - Pulsar
Q - Quasar
R - Rogue Planets
S - Satellites
T -   $\color{red} ?$
U - Universe
V - Variable Star
W - White Dwarf
X - X-ray Star
Y - Yellow dwarf star
Z -    $\color{red} ?$


But I couldn't think of something well-known from the letters K, T and Z. 

I tried to avoid using name of something specific object for ex. K - Kuiper Belt.

Can you please help me in completing this list?

Thanks!
Seems a little contrived, essentially you just have to dig deep enough to find a specific enough category that matches the letter. But here you go :

K - KBO (Kuiper Belt Object) , if you still don't like that you could use

K - Kreutz Sungrazer (A type of comet, https://en.wikipedia.org/wiki/Kreutz_sungrazer)

T - T-Tauri Star (A type of variable star, https://en.wikipedia.org/wiki/T_Tauri_star)

Z - Z Camelopardalis star (https://en.wikipedia.org/wiki/Z_Camelopardalis_star redirects to Dwarf Nova, scroll down)