The Big Dipper isn't a single star, but an asterism - a pattern of stars. Each star in the Big Dipper has its own color temperature and luminosity. Here's a breakdown of the main stars:

Star | Spectral Type | Color | Luminosity (compared to the Sun)

------- | -------- | -------- | --------

Dubhe (α Ursae Majoris) | K0 III | Orange-yellow | 85 times the Sun's

Merak (β Ursae Majoris) | A1 V | White | 1.5 times the Sun's

Phecda (γ Ursae Majoris) | A0 V | White | 3 times the Sun's

Megrez (δ Ursae Majoris) | A3 V | White | 1.5 times the Sun's

Alioth (ε Ursae Majoris) | A1 Vp | White | 100 times the Sun's

Mizar (ζ Ursae Majoris) | A1 V | White | 30 times the Sun's

Alkaid (η Ursae Majoris) | B3 V | Blue-white | 140 times the Sun's

Color Temperature:

* Blue-white stars like Alkaid are the hottest, with temperatures around 10,000 to 30,000 Kelvin.

* White stars like Alioth and Merak have temperatures around 7,500 to 10,000 Kelvin.

* Orange-yellow stars like Dubhe are cooler, with temperatures around 3,500 to 5,000 Kelvin.

Luminosity:

The luminosity of a star is how much energy it emits. The Big Dipper stars vary greatly in luminosity, with Alkaid being the brightest and Megrez being the dimmest.

It's important to remember that these are just approximations. The exact values for color temperature and luminosity can vary slightly depending on the source and measurement methods used.