Blue stars are typically very hot and luminous, which means they have high absolute magnitudes. However, there's no single absolute magnitude for all blue stars because their luminosity varies greatly.

Here's a breakdown:

* Blue supergiants: These are the most massive and luminous blue stars, with absolute magnitudes ranging from -5 to -10.

* Blue giants: These are still very luminous, but less massive than supergiants. Their absolute magnitudes typically fall between -2 and -5.

* Blue main sequence stars: These are the most common type of blue star, and they have absolute magnitudes ranging from 0 to -3.

So, while there's no single answer, most blue stars have absolute magnitudes that are negative, indicating that they are very luminous.