Questions tagged [stars]
For questions about luminous spheres of plasma held together by their own gravity, generally comprised primarily of hydrogen and helium.
468 questions
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Metallicity in super-metal-rich objects in the brown dwarf/red dwarf boundary [migrated]
I am trying to make a red dwarf with twice the metallicity of the Sun. What could its theoretical minimum mass in Jupiter masses be?
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How would a Hot Jupiter work in a P-Type Binary System?
This is my first time using the board so sorry for any mistakes.
I am currently designing a stellar System for my fantasy world. It is a P-Type Binary system which I have based upon a modified Keplar-...
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Is it possible for two stars to orbit a planet? [duplicate]
I recently learned about circumbinary planets ("recently" as in a few minutes ago) and I saw that there are cases in which a planet can orbit around one star, yet its orbit is close enough ...
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In an eclipsing binary orbited by an Earth like planet, would the drops in brightness be noticeable?
An eclipsing binary is a binary star system that periodically eclipses one another. There is a drop in total brightness when the primary eclipses the secondary and a smaller drop when the secondary ...
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Flare stars and habitability
I wanted to make a star that is a red dwarf, but it is a flare star, as it goes through random increments in brightness by a factor of 2. If the star mostly flares on a 70° inclination, and my ...
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What would be the most likely colour of leaves on plants on a planet orbiting a red dwarf?
Imagine a red dwarf star orbited by a considerably Earth-sized planet in the star's habitable zone. Assuming the planet has a sufficiently powerful magnetic field to protect its surface from the star'...
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Is it possible for a type 3 civilisation to use a blackhole bomb to stop a gamma ray burst?
A gamma-ray burst can be caused for multiple reasons. Some of the more common ones is that either a supermassive star undergoes a supernova and collapses into a black hole, two neutron stars collide, ...
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Where would this star's habitable zone be in AU?
I am making a hypothetical solar system. I want to know where the star's habitable zone would be located (in AU). Here are the characteristics:
Star name: Undecided
Star designation (preliminary): ...
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Is this solar system mechanically possible?
Say, hypothetically, you have two terrestrial planets (b,c), one gas dwarf(d), and one gas giant(e) all orbit the habitable zone in some manner.
b, c, and d all have an orbital resonance, which cause ...
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In this infant (<500 million years) solar system, how far would each orbit be to be stable?
Here's the story: There is a solar system that is still a baby, less than 500 million years old.
There are a total of eight stars clumped into four binaries, each one with its own habitable zone. ...
CommunityBot
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Plausible orbit to have a visible object slowly circle over the night sky
I want to have the inhabitants of a particular world - doesn't have to be a planet, can be a moon - be able to see a certain point of light - can be a planet, moon, star, whatever - moving in the sky ...
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Astro-Mechanics: Plausibility check for binary system merge
I have a binary system composed primary about a brown dwarf and a k6.6V star that's the fusion of the system 1 and 2 7.41 billion years ago, I'll tell you the story and I'll ask the question after the ...
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Stability in my habitable planet orbiting a binary system
I'm making a worldbuilding project mainly focussed arround an habitable planet that orbits a binary system and I have a question about my system.
My planetary system is an S-type (A main star in the ...
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Would this simplex ternary system be stable?
I'm trying to make a trinary star system but I'm not sure how it would work. The primary star is an M0Ve star (red dwarf flare star). The orbits of the other two stars are slightly more complicated. ...
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Can I replace the Sun with a non-nuclear equivalent?
The Scientocratic Hivemind has killed the Fire Deity at the cost of erasing the Earth's sun. For the sake of the lifeforms of this Earth before it goes away, it refines the Deity's corpse into a Sun ...
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What would the sky look like on a planet under a green sun? [closed]
Basically what the title says. I know green stars are completely impossible, but this is a fantasy world with completely different laws of physics, so on a planet with a green sun, what color do you ...
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Can I cause a star to go supernova by altering the four fundamental forces?
I have the Scientocratic Hivemind. It has the ability to create and envelop things in a magic field. Within this field, it can choose to strengthen or weaken the four fundamental forces governing the ...
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Can a star that initially started with less energy output than the sun (when it was young) evolve to be as luminous as the sun in the same time period
According to this work and worldbuilding pasta’s predictions on the water condensation inner limit for stellar habitable zones, a star like the sun cannot have a planet with liquid water on its ...
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How many Consciousnesses could exist in a Matrioshka brain built around an O class star [closed]
(Note I am both autistic and new to this platform, I might not word or ask questions well and I might make questions confusing so if I do something wrong please tell me how to fix it)
So a ...
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Would you be able to look directly at the Sun if it were a red giant?
For the moment, let's ignore the fact that the Sun is theorized to swallow Earth when it does decay into a red giant. We will pretend that it gets big enough to eat Venus, and stops there.
It will ...
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Would it be possible for a somewhat distant bianary star system to have a planet orbiting their barycenter within both their orbits?
There are 2 stars in a binary system, 268 AU apart from each other. Both are about 1 solar mass.
Would it be possible for some planet to be orbiting their barycenter (the center mass of both starts),...
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How can the stars be wrong, so that an observer realises they're not in our world anymore?
There is a common trope in fiction: when a character find themselves in a dark place out of this reality (somewhere in the eldritch realms, dreamscapes, lost cities of Carcosa or R'lyeh, etc), at ...
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How bright would it be at night on my planet?
My planet is in a binary star system where the second star orbits from pretty far off, about double Neptune's orbit. I've already confirmed that the star will be visible during the day, but how bright ...
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Binary Star System Physics
I am envisioning a planet that has two orbiting stars: a small yellow-white F class and a larger orange K class star. The stars were once closer and created a more tumultous tectonic history but since ...
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Would this star be visible in the sky during the day?
From the surface of an earthlike planet orbiting star 1, would start 2 be visible during the day?
Would it have any noticeable effect on the light level at night?
Star 1:
Class:
Main sequence type ...
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What is the largest possible appearance of a celestial body in the sky?
In SciFi Art we often see planets/moons/stars fill enormous amounts of the visible sky. I'm wondering what the theoretical limit for this is realistically, since there are maxima for the possible size ...
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Various eclipses in a P-type binary star system?
Trying to make a world with a P-type binary star system, with a habitable planet orbiting around them, and one moon orbiting said planet. I am terrible with physics so I've been wondering if any of ...
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The rotation of the sun's core doubles in speed every 10 years. How many years before the situation turns apocalyptical?
I'm asking this because I'm writing a fictional story where I need a doomsday scenario that means humanity must escape the earth. The timeframe that would fit the plot of the story would be in the ...
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Necessary distance for an ammonia world from Toliman
I am designing a planet that orbits the star Toliman, (Alpha Centauri B), which orbits well beyond the conventional Goldilocks zone. This planet has a similar radius to earth (6240 km) but its mass is ...
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A calendar/timekeeping system based only on the stars?
I'm playing with an otherwise earthlike world where I have handwaved away the visible sun and moon: anytime you look at a cloudless sky, you see stars, and only stars. How can the people of this world ...
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F type and K type Star Binary
I'm designing a worldbuilding project and the first major hurdle I'm encountering is the star(s) I want to have.
The primary star is an F9V - F8V star with a mass of 1.13 - 1.15 Solar Masses, a radius ...
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How far apart ought my type-S binary stars be if each is to host a stable planetary system?
Consider a G-class star (0.9457 Msol) as the primary and a M-class dwarf star (0.4335 Msol) as the secondary. If I want a stable planetary system around each (particularly the G-class), then how many ...
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Could sapient life evolve in 2 billion years?
I am imagining a race of beings called Loshp, who evolved on a planet orbiting an F-type star. These stars live for only 4 billion years tops before evolving into a red giant, and half that time was ...
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Could a sky be green(day)->purple(dusk)->black(night) and still be breathable?
similar requirements but green.
The reason this doesn’t answer my question is because I’d rather not have aeroplankton
Similar story with this one and I want it permanently habitable.
It takes place ...
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In regards to mass and luminosity, what are those mystery stars?
Long ago (4.6 billion years, to be exact), a hyper-advanced alien civilization had created a solar system from scratch. Somehow, they had artificially prolonged the center of the solar system--a ...
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Positioning the second sun in a binary star system so that a tidally locked moon of a gas giant is not illuminated by it, but the gas giant is
Working off this question and its suggestion of binary star systems to increase the length of 'day' on a planet without increasing the length of 'night'
I have a gas giant (1.2 Mass/Jupiter, 1 Radius/...
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Looking for a Specific Planet
I know my title isn't the most specific, but the planet I am looking for is. I have been looking through many exoplanets and I can't seem to find what I am looking for, the closest I have found is ...
CommunityBot
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How to calculate the expected rotational speed of a star
I am working on fictional stars, and I want to have as many points about them as I can, and most things I found relatively easy, except for rotational speed.
I am not sure exactly how to find at what ...
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Very large orbit binary/trinary star systems
In my universe, Ancient Aliens once visited Earth with consequences.1 At that time they left instructions2 that 5,000 years3 in the future something would happen.4 The instructions left behind a ...
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How visible would stars be from a planet orbiting an M-class star?
I have a planet orbiting at 0.2067 AU around a M-class red dwarf of mass and luminosity 0.4037 Msol and 0.0286 Lsol, respectively. The planet has an atmosphere of 93% CO2 and 3 atm. What I wonder is, ...
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How to find visibility of stars given a certain moon brightness
How would you be able to calculate what magnitude of stars would be visible given a certain brightness of the moon. As I know that the visibility of stars are based on their compared magnitude to a ...
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Auroras of a planet around an active M7 red dwarf
A planet the size of earth around a pretty active M7 red dwarf (think of M to X level flares almost every day) has a decent magnetic field of 0.5-0.8 Gauss, orbiting at a distance of 0.0443AU, with a ...
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Could a planet orbiting a g type main sequence star have yellow on its surface? [duplicate]
I had saw somewhere that a habitable planet orbiting a g type star same as our own could have yellow plants so could it?
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Do Forbidden Lines in Stars Often Come in Groups
In previous questions, I asked about how a K2V star could develop an [O VII] forbidden line and how those x-rays would create "pseudo-aurorae". Now, I'd like to know if my star could ...
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How close can a yellow hypergiant be to not affect a star system but also be important to the locals mythology
The Hypergiant
The hypergiant is a yellow hypergiant (YHG) which is currently cooling down and becoming a red hypergiant. It is roughly something that has a spectral type of maybe G3 0-Ia, though the ...
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Frozen Star- Red dwarf goes supernova, just because I froze it?
So as I mentioned in my previous question in the series, the parent red dwarf star of a one-planet system, Eridanus, has frozen over due to an unknown reason. By a "frozen red dwarf star", I ...
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Visibility of My "Psuedo-Aurorae"
I have been designing a habitable planet, its moon, and its star for a while now.
Background
My star is a K2V star with very strong solar wind and is about the age of the Sun. Every so often, when the ...
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Binary red giant?
I'm currently building a habitable tatooine-like binary system with the following stars:
Mass: 1.09 / 0.85 M⊙
Luminosity: 1.41 / 0.52 L⊙
Radius: 1.07 / 0.88 R⊙
Temperature: 6,087 / 5,230 K
Spectral ...
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Is there a way to make a K-star have an unusually strong stellar wind
I have been making a planet and its star for some time now.
Background
In a previous question, I asked how a star could develop an O VII forbidden line and I generally realized that the star needed to ...
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How could a K star develop an [O VII] Forbidden Line at 22.1 Å
The Goal
I have been designing a planet for quite a while now, and I would like the star to have an [O VII] forbidden line in its atmosphere. There doesn't need to be too much, but I need enough for ...
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