Questions tagged [astrophysics]
Questions involving the physics of the universe, especially the nature of astronomical objects, energy fields, and/or regions, rather than their positions or motions in space.
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How can one quickly screen a disk galaxy dataset for large-scale asymmetry?
I am looking for practical ways to quickly assess whether a disk galaxy dataset
shows large-scale asymmetry (e.g. possible stress-driven or lopsided structure)
before doing any detailed modeling.
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Are Redshifts as accurate as said to be?
I was reading about how scientists can measure how far away an object is by using redshifts to determine the element/where it is on a spectrum.
For example, if you take hydrogen and contain it in a ...
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Is this the equation to solving how fast an object moves away from earth?
I read a book by Dr. Richard Hammond recently, and in it there was the equation to calculate the velocity of how fast an object moves away from us. This was the equation:
$$v = H_0 ×d $$That is (...
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Is there a measure of astronomical distance that is not Earth-specific?
On planet Earth, the Astronomical Unit and the light-year are (fairly) well-defined.
To a Martian, the Astronomical Unit is 50% bigger and given the longer year, their light-year is almost twice as ...
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Is shape estimation a prerequisite for optical modeling in comet studies, such as for 3I/Atlas?
Based on discussions, observations suggest starting with precise motion tracking (e.g., probability and precision characteristics, including non-gravitational accelerations), then estimating mass/...
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Can we theoretically estimate the number of stars in an open cluster using the IMF?
Can we theoretically estimate the number of stars in an open cluster using the IMF? If it's possible, I’d like to know what physical quantities need to be measured observationally when estimating the ...
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What is this time dilation adjustment that has to be done for high-z objects? [duplicate]
In knocking down someone's personal Astrophysics theory, @profrob said, "How does it explain the $(1+z)^{−1}$ time-dilation observed for Type Ia supernova curves and gamma ray bursts?"
Does ...
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What is meant by the 'King core radius'?
While looking for a parameter that represents the extent of a star cluster, I came across the King core radius ($r_c$). However, even after reading papers, I still don’t understand it. What does the ...
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Could cometary non-gravitational acceleration be linked to surface cohesion transitions?
In several comets, including the interstellar comet 3I/ATLAS, a non-gravitational acceleration is observed, i.e., a net thrust not fully accounted for by gravity. While outgassing is known to produce ...
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Rigel vs Betelgeuse
Why is Betelgeuse so large compared to Rigel, even though it has less mass and is much cooler? Shouldn't it be the other way around, since $PV=nRT$?
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I was struggling to understand the concept of arcminute which is corresponding with arctangent, and just couldn't figure it out. A practical riddle
Regarding this formula;
θ = 2arctan(d/2D),
in which,
θ is the angel in degree version of arcmin,
d stands for diameter of the object which has subtended the angle of θ or arcmin at the distance of D.
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Could not Angular momentum of Universe if non-zero be detected because everything would be travelling outwards in curved paths.?
If there was a general overall spin of our Universe I would have thought we would have been talking about the correction required for objects travelling in curved paths due to conservation of momentum ...
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What exactly is the difference between planetary nebula and type ii supernova?
What exactly is the difference between planetary nebula and supernova? Both involve a dying star shedding its outer layers, but what's the exact mechanism for a planetary nebula? A supernova involves ...
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How did Hubble determine that the Cepheid was actually located within the Andromeda galaxy?
When Hubble discovered that the Andromeda “nebula” was actually a separate galaxy from the Milky Way, he did so by determining the distance to a Cepheid variable star located within Andromeda. How ...
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Practical strategies for calculating XSPEC errors?
I fit a pretty complex model (some 15 free parameters) using XSPEC to some observation data. Even though the fits themselves are fine, calculating the error on those models is proving to be a huge ...
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