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Questions tagged [temperature]

Temperature is a measurement of the average kinetic energy of the molecules in an object or system. In simpler words: it's the degree or intensity of heat present in a substance or object that is commonly measured with a thermometer.

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Why doesn't the equipartition theorem disallow spinning dust?

This excellent answer to the question What is the physics of the “spinning dust” contribution to Cosmic Microwave Background measurements? Is well sourced. The abstract of one of the papers there, ...
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Why the forbidden lines of [OIII],[NII] and [SII],[OII] are sensitive to electron temperature and electron density, respectively?

I am trying to understand the topic of "Metallicity estimates", either HII regions or planetary nebula. For this latter, the electron temperature (and density) must be known. I am studying the ...
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Temperature gradient in stars

It is a well known fact that in stars, there exists a temperature gradiënt. The observational reason is because we perceived spectral lines in the otherwise continuous spectrum of a star. If this ...
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What is Earth's average temperature as a whole? [closed]

I would like to know, what is the average temperature of Earth as a whole planet, not just its surface temperature. Hope the following scenario will make it more clear what I mean: Imagine, that we ...
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Air temperature range recommendation for observations in a summer night with an entry level telescope?

Recent nights where I try to make my first observations with the entry levell telescope Seben with 114 mm mirror it seems that for lenses less than 6 mm details go lost due to warm air refraction (as ...
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Are brown dwarf masses notoriously difficult to measure?

The Next Big Future article Rogue Exoplanet 12.7 times bigger than Jupiter is 20 light years away SIMP J01365663+0933473 has a magnetic field more than 200 times stronger than Jupiter’s. The object ...
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Why is the Warm-Hot Intergalactic Medium (WHIM) so hot, and what is “collisionless shock heating”?

The Phys.org article Researchers find last of universe's missing ordinary matter says: Ordinary matter, or "baryons," make up all physical objects in existence, from stars to the cores of black ...
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How can the temperature of stars can be determined by their color?

How do you determine the temperature of a star by color?
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Gaia Gbp - Grp: why does it get larger as star gets redder?

As an enthusiastic amateur scientist, I'm plowing my way through a cool Gaia DR2-based paper, "An Empirical Measurement of the Initial-Final Mass Relation with Gaia White Dwarfs". I'm doing all right, ...
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H-R diagram, Double stars

Can someone help me? I have a case, like, we have H-R diagram and two stars on it. One of them is a blue star on main sequence, another is a red giant. They have equal luminosity. If they are in a ...
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Is there a comfortable part of Venus's upper atmosphere?

I know the surface of Venus is very hot, but that it gets cooler the higher you go in the atmosphere. I have heard that there is a section in the atmosphere of Venus that might be somewhat habitable ...
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What is the temperature under the surface of Mercury?

What is the temperature under the surface of Mercury? I know at the surface the temperature varies greatly (-297 F to 801 F). I also realize that the answer would likely depend on depth. Do we know ...
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What would the pressure and temperature of gas be, right above Jupiter's gas/liquid boundary?

Older pages like this "Exploration of the Solar System" course page describe the transition as being a few hundred kilometers down. More recent findings seem to put the boundary deeper. See The ...
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Venusian polar surface temperatures

I've stumbled across several articles about how the Venusian polar high atmosphere is really cold. What these articles appear to fail to specify is what the surface temperatures of the poles are. I am ...
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Temperature of Earth if tidal locked with the Sun?

Assume the Earth somehow stopped spinning once every ~24 hours, and instead started rotating at ~365 days per rotation, so it effectively would end up being tidal locked with the Sun. In this ...
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Predicting Temperature Variation on Planets with High Eccentricity or Long Diurnal Periods

Whew! That title was a mouth-full, but accurate I hope. What I'm trying to figure out is a model for calculating the approximate temperature variation for a generally earth-like planet (similar ...
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How do we define temperature in outer space?

I was recently reading an article on space.com about : What's the Temperature of Outer Space. They said : Some parts of space are hot! Gas between stars, as well as the solar wind, both seem to be ...
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What contributes the most to the seasonal temperature variation?

The seasonal temperature is ultimately due to the precession of the Earth around the axis. But what I'm curious about is... is it due more to the side experiencing winter being farther from the sun ...
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Complete Sun altitude-temperature graph?

I found a bunch of partial graphs. For interior: src For surface: src The closest thing I could find that would cover more than innermost piece of corona is for sigma binaries. As if solar corona ...
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Calculating star radius from temperature and absolute magnitude - what am I missing?

In an attempt to visualise nearby stars, I've tried to get the star radius (measured in solar radii) using the equation provided on the following site: http://cas.sdss.org/dr4/en/proj/advanced/hr/...
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How do I get the luminosity of a main sequence star based on its spectral class?

I am trying to calculate stellar habitable zones using the equations found here: $$ r_i=\sqrt{\frac{L}{1.1}} $$ $$ r_o=\sqrt{\frac{L}{0.53}} $$ I want to be able to calculate this by having a user ...
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Why are there no ISM clouds with temperatures between 100 and 6,000K?

In the interstellar medium, there are several different diffuse phases of gas, distinguished by their density and temperature. Specifically, the cold neutral medium has temperatures from ~50-100 K and ...
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Why didn't the Big Bang produce heavier elements?

Shortly after the Big Bang, temperatures cooled from the Planck temperature. Once temperatures lowered to 116 gigakelvins, nucleosynthesis took place and helium, lithium and trace amounts of other ...
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The relation between the energy of star and heating effect

Because a star's temperature is an indication of the energy passing through each unit of its surface, it follows that for cool red and hot blue stars of identical luminosities, the cooler red star ...
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Is an ice planet made only by Ice?

Is an ice planet made only by ice? What causes the water to conglomerate and form ice in a planet? Even if the planet is not made entirely by ice but has an high % of ice (e.g. 50% ice), how can it ...
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Why is the Sun so bright, but you can feel it far away?

First of all, the Sun's surface temperature is only about 6000 K. Years ago I was working at at a melt work with furnace temperatures 0f about 2-3000 K; of course you could not be near a furnace ...
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Precipitation and weather and seasons on other planets [closed]

I have participated in an exhibition on astronomy and decided to make a project on the topic "weather season and precipitation on other planets" I have the knowledge about the weather on earth but I ...
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How could lithium burning take place in a quasi-star?

According to Begelman et al. (2008), one of the most distinguishing features of the hypothetical quasi-star is that it's supported by radiation pressure from the accretion disk of the black hole in ...
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Calculate planet's surface temperature by distance from star [duplicate]

If the planet and star in question are very similar to the Earth and the Sun, how can I calculate the planet's surface temperature by knowing the distance from the star? This question was originally ...
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If Mars were tidally locked to the Sun, what would the temperatures on its surface be like?

Since there's very little atmosphere on Mars, it doesn't matter much whether the Sun is in the zenith or hanging just above the horizon: without the atmospheric "filter," the sunlight would have ...
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Are gas giants supported by thermal pressure?

I've heard gas giants are supported because there is an equilibrium between thermal pressure and gravity. That is, if Jupiter were to suddenly begin compressing, temperatures would increase to the ...
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Why is the exoplanet HD 131399Ab so hot?

Recently, a fascinating triple-star system with an exoplanet has been discovered (arxiv). I'm very surprised about the temperature of the exoplanet: it is roughly 850 kelvin, even though its orbit ...
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How massive can a cold solid object be?

I understand that a neutron star is dense enough that adding more matter will increase the amount of degenerate matter directly, and the limit to its size is about 1.4 solar masses. But if an object ...
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Is there a limit to how hot an object an get? [closed]

Temperature is a measure of the average kinetic energy of particles in a given place (correct me if I am wrong) so there must be a definite limit to heating like there is an absolute zero to cooling. ...
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Definition of stellar core?

This is a basic question, but I may as well ask it. I had always thought that the core of a main-sequence star is defined as the part hot enough for nuclear fusion. Some dictionaries seem to agree ...
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Why does lithium fuse at lower temperatures than hydrogen?

This is a basic question, but it's been bugging me. In the Wikipedia article for lithium burning, it states that: Stars, which by definition must achieve the high temperature (2.5 × 10^6 K) ...
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How cold is interstellar space?

The vastness of space brings me a sense of chilliness even though I have never experienced it, although I wish to. Just how cold is interstellar space (on average)? How is this even measured? I mean ...
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How much heat emanates from the planets after formation?

The 2nd answer to this question by MBR got me thinking about this. Is there some general guideline for residual heat a planet should emit, say 4.5 billion years after formation. I'm defining heat ...
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What is the temperature 55 km beneath the surface of Mars?

What is the temperature 55 km (34.18 miles) beneath the surface of Mars? The reason I ask is that I want to know if it might be habitable for a possible future colony if they could dig that deep (...
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Why can't neutron stars ignite and explode?

Beyond the Chandrasekhar limit, white dwarfs become extremely hot. As a result, previously unfusable carbon can become fusable, causing nuclear reactions. This leads to thermal runaway and ultimately ...
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Why is Rosetta's Comet so “warm”?

Rosetta Comet AKA 67P/Churyumov–Gerasimenko has the surface temperature range of -43 to -93 degree Celsius. Now, if we compare that with the Mercury (I chose Mercury cause it's closest to the Sun ...
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Which moons have cold traps? (i.e. low ecliptic inclination in orbital and rotational axes)

Both the Moon and Mercury have polar cold traps in polar craters, with signs of volatiles. This is of course not as interesting on a moon in the outer Solar System which consists of volatiles anyway. ...
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How to calculate the temperature of a star

I need a way to calculate the effective temperature (surface temperature) of a star for a stellar model. I need something in the form Te=.... I have: Radius in m mass in kg the composition of ...
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What is the temperature inside a Black Hole?

Is it insanely hot? Cause of so much gravity? Is it close to absolute zero? Cause the matter is so closely packed, there is hardly any space for particles to move? Is it room temperature? Cause Cooper ...
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What are the implications if the Sun was formed in a warm nebula?

Molecular oxygen O2 has been found on comet 67P/C-G in a ratio of 3.8% to water, which is much higher than expected. An explanation proposed is that the Solar System formed from a molecular cloud ...
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What is the temperature on surface of Pluto facing Sun?

According to wiki page, the mean temperature of Pluto is 44 degree K (-229 degree C). However, given that Pluto is tilted greatly and there is daylight for long periods on part of Pluto facing the Sun ...
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Is a supernova's core temperature absolute zero just before collapse?

I thought a supernova's core temperature was absolute zero just before it collapsed, as it has run out of all nuclear and thermal energy, but I haven't been able to confirm this online anywhere and I ...
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What is the highest recorded temperature in space

What is the highest recorded temperature in space? I'm not asking about Planck temperature that is a fraction of a second before the Big Bang. I'm asking about the temperature that has been recorded ...
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What is space temperature around Earth?

What is the equilibrium temperature that a black body will reach at the Earth's distance from Sun?
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Galaxy Cluster Temperature

I've read once in an article that the temperature of the medium between the galaxy superclusters is extremely high. What does that temperature really mean? particles' velocity? Why is that so? Is ...