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Astronomy/Goldilock zone around HR 5171


I just discovered about HR 5171 which is a peanut shaped binary star system. I was wondering what would the goldilock zone look like.
Would it also be peanut shaped? I.E. Would it be hotter when you could see the two suns and colder when the smaller one is hidden?

Thank you

Hi Simon,

Lots of stars are in binary (two star) systems.  If they are close enough, you get a system like HR 5171 where the atmosphere of one nearly envelopes the other.  It is actually a very common phenomenon, however the stars aren't usually that big like the one in HR 5171.

There have been quite a few planets found orbiting a system with two stars and most of these have been found by the Kepler space telescope.  There is a debate about how habitable these planets can be, but at least a few that have been found are believed to be in the goldilocks zone.  

However, it has been calculate that close-binary systems (like HR 5171) may be better at hosting habitable planets.  That is because that having two very close stars actually acts like one big star, creating a very big goldilocks zone.  This habitable zone would be slightly oval, however it wouldn't have an indent like a peanut akin to the binary system.

In short, it would have an odd shape, but not quite peanut-like.

I hope this helps!



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Brad Tucker


I'm happy to answer any general questions about Astronomy, Astrophysics, and Cosmology. I'm also happy to take general, specific, and detailed questions related to supernovae, Baryonic Acoustic Oscillations, the Cosmic Microwave Background, dark matter, dark energy, and the Big Bang Theory. I'm also happy to chat about Astronomy/Astrophysics education and careers, and philosophy and science.


I am a professional research astronomer/astrophysicist/cosmologist. My research focuses on studying supernovae and using them to measure the properties of the Universe, such as how fast it is growing and what it is made of. I also frequently give talks to school groups and the public, and am a regular guest on various radio stations.

Current Research Fellow at Mt. Stromlo Observatory, the Australian National University, and in the Department of Astronomy, University of California, Berkeley.

Lots of journals, including the Astrophysical Journal, the Astronomical Journal, and Nature. I am currently in the middle of writing my first popular book.

B.A. Philosophy, University of Notre Dame, Notre Dame, IN USA B.A. Theology, University of Notre Dame, Notre Dame, IN USA B.Sc. Physics, University of Notre Dame, Notre Dame, IN USA Ph.D. Astrophysics, Mt. Stromlo Observatory, the Australian National University, Canberra, ACT, Australia

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