Questions tagged [red-dwarf]

Questions about red dwarfs, the smallest and most abundant stars in the universe.

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Is there any way for a planet orbiting a red dwarf in the habitable zone to not be tidally locked?

Is there any way to avoid the tidal locking of a planet orbiting a red dwarf in the habitable zone? For example, could a planet with a 90° obliquity and large moon avoid such a situation?
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1answer
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If Sunlike stars become a red giant and eventually a white dwarf, what do red dwarfs become?

The Sun is said to become a red giant at the end of its life (before that it will become an orange subgiant first and then an orange giant or so) and after ejecting its outer layers it should become a ...
10
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3answers
362 views

Existence of planets larger than their host star?

The mass region of objects between ~ 0.5 Jupiter masses and 80 Jupiter masses (gas giants through to brown dwarfs and red dwarfs) is typified by an almost flat relationship with object diameter. There ...
8
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1answer
538 views

Why do planets in red dwarf star systems tend to have a higher probability to get tidally locked?

I have read about about the habitability of red dwarf systems on Wikipedia, as well as some web articles on similar topics. The problem is, it does not explain why and how it happened. Google search ...
8
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1answer
462 views

The colour of blue dwarf stars

The paper "M dwarfs: planet formation and long term evolution" describes blue dwarf stars, a hypothetical next-stage in the lifespan of red dwarf stars within a certain mass range, after which they ...
7
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1answer
608 views

Is the mechanism of solar flares on red dwarfs and brown dwarfs the same as that on the Sun?

The Sun has solar flares that are caused when there is a magnetic reconnection in the Sun's atmosphere, causing a loop of magnetic field to be ejected at high energy, along with a large number of ...
5
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2answers
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Are red dwarfs really 30-100 times our Sun's density?

This article by K. E. Edgeworth claims red dwarfs tend to be around 30-100 times our Sun's density. However, this seems a bit high. With smaller stars, mass tends to be proportional to radius but ...
5
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1answer
292 views

Would a red dwarf star resemble our own Sun at sunset to an observer on a nearby planet?

Suppose you're observing a red dwarf star at Noon from the surface of an Earth-like planet orbiting in the red dwarf's habitable zone, so that the red dwarf's luminosity is equal to our own Sun. Aside ...
5
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1answer
316 views

How do we know that 2MASS J0523-1403 is a red dwarf?

I was reading about red dwarfs, and stumbled upon this article about the least massive red dwarf, and noticed several peculiarities: The spectral type is L2.5 The luminosity class is V The mass is 67....
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1answer
271 views

Are there any hot jupiters orbiting red dwarfs?

Do we know of any hot jupiters that could be orbiting a red dwarf (or, more probably, orbiting a barycenter between the two)? Is this scenario even physically possible?
3
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1answer
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Would the electron cyclotron-maser emission mechanism affect Proxima b's ability to retain an atmosphere?

In a recent arXiv preprint, Pérez-Torres et al. "Monitoring the radio emission of Proxima Centauri" claim the detection of radio emissions synchronised with the orbit of the planet Proxima b....
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1answer
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Is there a way to estimate the age of M dwarf stars?

Wolf 1061 (only 13.8 ly away) was recently found to have three rocky planets one of which is in the habitable zone. It was stated on the english wikipedia site that it has a very stable light curve ...
3
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0answers
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Is it possible for any of the planets in the TRAPPIST-1 system to have moons?

All of the planets in the TRAPPIST-1 system are all orbiting very closely and are somewhat large. Would it be possible for at least one of the planets to have a stable moon in orbit around it? Or ...
2
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2answers
159 views

Will all of the gas in the universe be converted into red dwarf stars?

Red dwarfs have lifespans of trillions of years and are also the most abundant stars, making up 70% of the stars in the Milky Way. No red dwarf star has ever died and none will die for a very, very ...
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2answers
575 views

How do I understand a brown dwarf with a M-type spectrum?

There are a large fraction of M dwarfs which are claimed to be brown dwarfs. Why do we still use M-type and not create a new stellar type like L, T and Y? The main signature of M is TiO absorption ...
2
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1answer
157 views

Red dwarf variation in Luminosity

I recently saw this video. The creator of the video says that one of the reasons for non-existence of life on planets around red dwarfs might be that these stars can increase luminosity roughly by a ...
2
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1answer
154 views

At what distance does Proxima Centauri become visible to the naked eye?

The red dwarf star Proxima Centauri is the closest-known star to the Sun (being about 4.2 ly or 1.3 pc away), however it's not visible to the unaided eye for it is too small and dim. I'd like to know ...
2
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1answer
62 views

Why is the SETI survey limited to only Red Dwarf Stars?

I was going through the official SETI website, when I came across this article on the same website which said : Today, the SETI Institute uses a specially designed instrument for its SETI efforts – ...
2
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1answer
367 views

The tidal locking problem concerning Earth sized planets in habitable zone around Red Dwarfs

Would twin planets orbiting around each other present a solution to tidal locking of habitable planets in red dwarf systems? It's an awfully easy equation to set up. I'm fibbing; I can't do it. I was ...
2
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1answer
52 views

How would tidal effects behave in this setup: An icy moon orbiting a gas giant, as the gas giant orbits a red dwarf? [closed]

Let me know if this is more appropriate for worldbuilding. Essentially, I'd like to know how tidal effects would behave in these circumstances (if it's even stable): An icy moon orbiting a gas ...
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0answers
235 views

Jupiter/Saturn's fate after Sun goes red giant and planetary nebula?

The solar wind contributes a very small amount of matter to the gas giants. As the sun approaches the red giant phase, the solar wind increases significantly. 10% of the sun's mass lost as solar ...
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0answers
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Does habitable zone take tidally locked bodies into account?

Imagine a tidally locked planet orbiting a red dwarf, where habitability is not situated close to terminator zone, but on a "small" cap normal to incident starlight (zenith) with permanent average +15 ...
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0answers
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Could a moon of a mini-neptune around a red dwarf harbour life?

I am planning a game where on could control evolution on an alien world. I was thinking red dwarf as per here Habitable Planet around Red Dwarf To my understanding three questions arise: Tidal lock ...
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1answer
63 views

Comparing orbits between a planet and Red Dwarf

I have a MATLAB problem, so I have an earth like planet orbiting around a sun like star and then there is a red dwarf on an elliptical orbit around the star that passes close to the planet. I want to ...
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1answer
111 views

What if a white dwarf is less massive than her partner?

For example: a system with a 0.2 solar mass white dwarf orbiting a 0.25 solar mass red dwarf. Does the red dwarf steals mass from the white dwarf or vice versa.
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1answer
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Do lower mass stars consume more hydrogen than higher mass stars?

If I understand correctly, red dwarfs consume all of their hydrogen and will eventually shrink into helium white dwarfs, whereas the higher mass stars will consume a fair amount of their hydrogen fuel,...
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2answers
51 views

What factors influence a star's temperature and density?

Assuming a relatively even proportion of mass and radius, a 0.25 solar mass and radius star would have a density of 22.5003 g/cm³, or about 16 times our Sun's density. However, there is obviously a ...
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1answer
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Are red dwarfs (M dwarfs) known to be strong infrared sources?

If so, why? Are they known to be surrounded by large amounts of dust? Do they typically flare?
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1answer
66 views

If the Earth circled a red dwarf/giant or a brown dwarf, would its sky still look blue? [duplicate]

I have the impression that in brown dwarf and weak red dwarf systems, everything looks more reddish on a planet, including its atmosphere regardless of composition. Suppose there's a planet having an ...