Here's why:

* Small: White dwarfs are the remnants of stars like our Sun. They are about the size of Earth, significantly smaller than their original star.

* Hot: White dwarfs are incredibly hot, radiating a lot of energy. They have exhausted their nuclear fuel and are slowly cooling down over billions of years.

* Dense: White dwarfs pack the mass of a star into a much smaller volume, making them incredibly dense. A teaspoonful of white dwarf matter would weigh tons on Earth.

Other possibilities:

While white dwarfs fit the description perfectly, there are other stellar objects that could also be considered:

* Neutron stars: Even denser than white dwarfs, neutron stars are the collapsed cores of massive stars. They are also very hot but much smaller than white dwarfs.

* Black holes: Though not technically stars, black holes are extremely dense objects with immense gravity that are also incredibly hot. They are much smaller than white dwarfs and are not visible due to their strong gravitational pull.

However, based on the characteristics of "small, hot, very dense", a white dwarf is the most likely answer.