One of the newest exoplanet discoveries is also one of the rarest. KELT-4Ab sits in a triple-star system. It takes three days to orbit the closest star, KELT-A. That star is orbited by two nearby stars, KELT-B and KELT-C.

According to, KELT-B and C are a lot further away and take nearly 30 years to orbit each other. The pair takes even longer to circle KELT-A. About four thousand years according to new research.

What would the sky look like from KELT-4Ab? It would be blinding. Remember, the exoplanet takes just three days to orbit the closest star, KELT-A. That also means the planet is tidally locked. One side always faces the sun, while the other is plunged into eternal darkness.

Here’s how the researchers describe it via

The view from KELT-4Ab would likely be one where its sun, KELT-A, would appear roughly forty times as big as our sun does to us due to its proximity. The two other orbiting stars, on the other hand, would appear much dimmer due to their great distance, shining no brighter than our moon.

A hot Jupiter

hot Jupiter

Image of HD 80606b based on data from NASA’s Spitzer Space Telescope

Triple star systems are cool to look at, but researchers hope to use this exoplanet to answer another mystery. ‘Hot Jupiters.’

When we began our search for planets outside our solar system, we assumed we would find things much like our own. Rocky planets near the front and gas giants in the back. Instead, we started finding gas planets like Jupiter, but orbits that take them much closer to their stars.

How Scientists Spotted That Triple-Star Exoplanet

Scientists were shocked when they discovered the first ‘hot Jupiter.’ But, the more exoplanet discoveries scientists made, the more our solar system seemed like the odd one out.

We don’t even understand the basics of these planets. How do they form? How do they end up in such close proximity to their stars?

One theory suggests a ‘hot Jupiter’ forms just like your typical gas giant. Then, the gravity from nearby planets or stars pushes them into closer orbits. Over hundreds of millions of years, these gas giants go from eccentric orbits to close, circular orbits.

Scientists are using NASA’s Spitzer telescope to study what they believe is a ‘hot Jupiter’ in the making.

Other theories suggest ‘hot Jupiters’ form in their current orbits. Scientists still don’t have the answers, but planets like HD 80606b and KELT-4Ab present perfect observation opportunities to figure it out.

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