The Star in the Sky

Discovered courtesy of Tumblr once more, are a set of pretty amazing visualisations originally from Halcyon Maps showing how drastically the sizes of stars can vary. These show how the view would appear from Earth if you replaced the Sun with a different star. As it happens, it varies a lot!

Everyone loves a good sunset, right?

Tiny, tiny Barnard's Star. Maybe too dim to give you a good sunset.

Earth is actually a lot further from the Sun than any of the planets known to orbit Gliese 581 are from their parent star.

Tau Ceti looks rather like it might make a good home for humanity someday. Assuming no one lives there already. It has at least 5 planets too, so we think!

And now I have the Star Wars music in my head again...

Sirius is younger than the Sun and about twice as massive. Remember to wear sunscreen when you visit!


There are some more on Halcyon Maps, where you can also buy prints!

Interestingly, while this shows the difference between star sizes, it’s not so accurate if you wanted the planet to be habitable. Halcyon Maps point out that this is just a concept because liquid water would never exist on planets with views like most of these. A Bit More Detail picks up on this too. The funny thing about habitable zones is that larger stars are brighter and put out more radiation, so habitable planets would be further away.

Interestingly, if an actual habitable planet were in orbit around a red giant star like Arcturus, the star would appear much smaller than the Sun, but much brighter. A little point of light so intensely bright that it can illuminate the whole sky. It’s a little difficult to imagine how it might look. The habitable zone is just that much further away from the star itself.

Conversely, in the habitable zone of a red dwarf, the star would loom, huge overhead. A dim but dramatic presence in the sky. It may seem disconcerting to creatures like us, but a planet under a red dwarf sun would likely also be tidally locked, meaning the Sun would never move from its position in the sky. It would hang eternally in the same spot. No sunrises and no sunsets.


About Invader Xan

Molecular astrophysicist, usually found writing frenziedly, staring at the sky, or drinking mojitos.
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