A star's brightness, or luminosity, depends on both its temperature and its size. While a hot star generally emits more light than a cooler star, its overall brightness can be affected by its size.

Here's an example:

A white dwarf star.

* Hot: White dwarfs are incredibly hot, with surface temperatures reaching tens of thousands of degrees Celsius.

* Small: White dwarfs are extremely dense and much smaller than our Sun, often only slightly larger than Earth.

Because of their small size, white dwarfs don't emit a lot of light even though they are very hot. This makes them appear relatively dim compared to larger, cooler stars.

Other examples of hot but not very bright stars:

* Neutron stars: These are even smaller and denser than white dwarfs, but they are also extremely hot. They emit X-rays and gamma rays, but their visible light output is very low.

* Some main sequence stars: While main sequence stars are generally classified by their temperature, there are some smaller, hot stars that are less luminous than larger, cooler stars.

In conclusion, a star's temperature and size both play a crucial role in determining its overall brightness. While a hot star may emit a lot of light, it can still be relatively dim if it is small.