Betelgeuse, one of the brightest stars we see, has been fading for months. It could signal a fiery explosion, but it may just be dust.

• Betelgeuse is a well-known and easily visible star in the Orion constellation.
• It's been fading in brightness, and astronomers aren't sure why.
• The star could be about to explode, or its surface could be shedding, creating space dust.
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One of the brightest and most recognizable stars in the night sky, Betelgeuse, is less than half as bright as it was five months ago.

Scientists have a few hypotheses about why this is, the most dramatic of which is that since Betelgeuse is a red supergiant, it will eventually explode in a supernova. The fading could indicate that the star is entering a pre-supernova phase: dimming and collapsing before it explodes.

But most astronomers don't think the star is headed for an explosion just yet.

That's because the star has experienced cycles of dimming and brightening before (though not this dramatically). It's a pulsating, variable red supergiant - which means its size and brightness can vary due to changes in activity of the convection cells on its surface and the heat in its atmosphere.

A third possible explanation for the dimming is that Betelgeuse could be shedding some of its own material back into space, creating dust clouds that obscure our view of the star. Astronomers are still exploring where that dust might originate.

"The phrase 'we are all made of stardust' is one we hear a lot in popular astronomy, but where exactly does this dust come from?" Emily Cannon, a PhD student who works with the European Southern Observatory, said in a statement.

Astronomers aren't yet sure which of these explanations is right. And to make matters more complicated, Betelgeuse's rate of dimming has slowed in the last week.

Here's what the fading star looks like.