The application of physical theory to celestial systems such as stars, planets, galaxies, supernovae, and black holes. Astrophysics proper is concerned with explaining phenomena more so than making observations, the latter falling under the purview of astronomy.

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Is there a natural source of Antimatter in this universe?

I was just asking if there is an natural source of Antimatter in this universe capable of creating simple molecules/compounds? So, any good answers?
2
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24 views

Why do some stars actually produce “Gamma ray bursts”?

I looked it up but I haven't found any explanation as to why some stars produce them, I understand that collapsing and merging stars produce them, but my question is why is the energy concentrated in ...
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21 views

What are these cycles in orbital eccentricity called?

I have created a simulator for planetary systems. When I run it with our own solar system and plot the eccentricity, aphelion and perihelion of the orbit of Earth i get these cycles. Do these ...
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3answers
62 views

is the potential energy of a black hole infinity

It appears like black holes posses an escape velocity greater than the velocity of light. It takes an atom infinity energy to travel at speed of light.Do black holes posses that energy to retain ...
2
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2answers
52 views

Measuring Rotation of Sun

If the sun had a uniform surface (i.e., if there were no sunspots to look at), is there a practical way to measure its rotation? In other words, if some external force flipped the sun's spin ...
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34 views

Could a satelite be pulled away by gravity while the object it was orbiting keeps unaffected in its own orbit?

I'm asking this, since I try to educate my self a bit in the field of astrophysics. From my point of knowledge the by title given scenario could occur. But I haven't yet read anything that sounded ...
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21 views

How do modern particle detectors identify and segregate different particles

What is the specific particle detector technology used at CERN or similar Institutions. Is it essentially a big digital camera? When said particles are detected, how are they segregated, How does this ...
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1answer
50 views

Special Relativity problem - proper time interval

The supernova 1987A explosion in the Large Magellanic Cloud 170 000 light years from Earth produced a burst of anti-neutrinos ν ̄e which were observed in terrestrial detectors. If the anti-neutrinos ...
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2answers
38 views

Is there a doppler effect on the images of stars around rotating black holes?

I'm an illustrator working on a project involving rotating black holes like those discussed in "Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar" by James, ...
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1answer
62 views

What is the invisible mass in the universe?

According to scientists, currently the edge of observable universe from the earth is about 14 billion parsec. This means that the diameter of the universe is nearly 91 billion light years. If we ...
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1answer
40 views

Where do astrophysical neutrinos come from?

What I really do not get about them is collisions of cosmic rays with light produces high energy neutrinoes but cosmic rays have a little energy maybe less than a 5000 electron volt. How do high ...
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35 views

If the Hubble constant is the result of acceleration of photon [closed]

This is not enough to change our understanding of universe? The Blueshift Paradox and Solution: The Blueshift Paradox: Z = ∆λ/λ(obs) = v/c ∧ H = v/d Astrophysics use the doppler effect to explain ...
2
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0answers
37 views

Nucleosynthesis: other than big bang and supernova

According to many texts, hydrogen and helium and traces of lithium-7 were created in a brief period after the big bang; helium is created through fusion (pp, CNO) in main sequence stars; elements like ...
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1answer
40 views

A question on Jeans's instability

I am a Physics student and I'd really appreciate if anybody could help me with an exercise my professor gave me a couple of weeks ago. It goes like this: Let us consider a spherical symmetrical gas ...
4
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0answers
72 views

Second order Fermi mechanism. Is there a mistake in the Claus Grupen book?

The second order Fermi mechanism describes the interaction of charged particles with magnetic clouds. This model leads to a collision-less acceleration of cosmic rays up to ultra high energies. A ...
4
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1answer
65 views

How does Planet 9's perihelion and aphelion affect the Kuiper belt objects?

Assuming that the existence of Planet 9 is confirmed and it really exists, how does it affect the orbits of the Kuiper belt objects? My understanding is that the discovery came in part from the ...
3
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1answer
69 views

Quasar redshift

The quasar 3C 273 has a redshift z=0.158. A question in a textbook: could this be a gravitational redshift instead of cosmological (=resulting from the expansion of space)? My answer: no. Firstly, ...
3
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0answers
20 views

Pressure inside a typical white dwarf

Does any one know the order of magnitude of pressure inside a typical white dwarf (better with reference)? Thanks! I think it should be $m_e^4c^5/h^3$ (may be multiplied by $\pi$), which is $10^{22} ...
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1answer
47 views

What would it be like if the supernova ASAS-SN-15lh was in the Milky way?

I'm simply wondering what it would be like if the super nova ASAS-SN-15lh (http://www.sciencemag.org/news/2016/01/universe-s-most-luminous-supernova-was-50-times-brighter-milky-way) was in our milky ...
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25 views

Variable speed of light impact on spectral absorption lines in distance luminous objects?

There are many other arguments as to the constancy of the speed of light (or more precisely, c). One thing I have been curious is what would the impact be on spectral measurements from distant ...
2
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1answer
32 views

What does it mean for a map to be “coadded”?

So there is this wiktionary definition of coaddition, but it's rather brief. Could anyone expand on this, perhaps giving a short example and explaining why its useful? The context that I initially ...
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1answer
28 views

Where can I find accesible educational material on the formation of the solar system?

I'm kind of scathing my head over this. First of all, I'm not a physicist of any kind, I'm a software developer, but I'm also a bit passionate about astronomy(usually read the news) and in my free ...
2
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0answers
27 views

What is the most commonly used density model for globular clusters?

It is possible to model a globular cluster using a number of different density models: Plummer model King model Isothermal sphere . . . They all have advantages and disadvantages, depending on ...
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38 views

How are planets distributed in elliptical galaxies?

I'm trying to figure out if planets are equally distributed in galaxies (I'm assuming they aren't) or if there is some logic behind their distribution.
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30 views

Startups for astrophysics [duplicate]

Between astrophysics and quantum mechanics both are interesting and I've had an answer for quantum mechanics but is there anywhere I should start at first or any books? I'm 14 so I don't really know ...
3
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1answer
33 views

Classification of binary star system

I'm not an astrophysicist, but I'm studying a binary star system and I need some clarification about star classification. The spectrum seems to be F8V-like. The absolute magnitude is between 12 and ...
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17 views

Dust mass-loss rate from a massive star given a set of parameters?

I've been looking for examples at how mass-loss rates are determined. I'm studying a circumstellar dust shell ejected from a Wolf-Rayet star. I have some parameters like, expansion velocity of the ...
3
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1answer
54 views

Limitations of 2D point-mass Dynamics of the solar system

To model the solar system, I took the planets to be point masses, used newtonian mechanics and modelled the orbits as circular (only Mercury's orbit has appreciable eccentricity). The entire system is ...
3
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1answer
68 views

What is the average temperature of mass in the universe?

That is, ignoring speculative concepts like Dark Matter and just summing across stars and gas clouds etc
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2answers
92 views

How is it possible that Thermosphere can maintain so much heat? [closed]

Thermosphere is the Layer of Atmosphere in approx 100-1000 km altitude. Particles in thermosphere are typically at 1400 K temperature. But the sun activity can raise the temperature up to 2300 K. ...
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1answer
33 views

How and why do sunspots occur?

I am studying sunspot behavior, and the causes for the occurrence sunspots occur. I've come across the phrase 'local magnetic fields of the Sun'. I have no idea what that means. Can someone please ...
3
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0answers
53 views

How do we know what happens to stars during their life cycle?

It is common knowledge than Sun-sized stars will eventually become red giants, and later they will get gradually smaller again until they cool down into a brown dwarf, and that bigger stars can ...
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1answer
107 views

Simple metric of stellar collapse

Is there a simple metric (Lorentzian manifold) known which exhibits the formation of a black hole while not having any white hole counterpart and which moreover satisfies the strong and dominant ...
0
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1answer
184 views

Can a perfect insulator, i.e. matter devoid of all electrons conduct electricity?

Few weeks ago an article on Nautilus was published on Neutron stars. After reading that, a question was asked by a friend of mine. He asked if matter in neutron star would be able to transfer ...
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36 views

Visible Mass Distribution in a Galaxy [closed]

Is there any known relationship between stellar density and distance from the galactic centre? I want to know how the visible matter is distributed in the galaxy, especially at the bulge.
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49 views

As the World Turns [closed]

Does the Earth's axis change with the magnetic reversal as it is taking place?
3
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2answers
76 views

Is sun a black body? [duplicate]

My teacher told me that sun is a black body but after reading at various sites whre they say that sun is not a black body but has black body radiations because it cannot absorb all radiations.
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49 views

Does a planet's orbital angular momentum affect its rotational angular momentum?

For example: If the moon was closer to the earth, assuming the orbital momentum was conserved and not worrying about earth's rotation, would the moon's rotation rate be effected?
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2answers
66 views

We say Light is Red-Shifted or Blue-shifted from faraway stars and galaxies [closed]

We say Light is Red-Shifted or Blue-shifted from faraway stars and galaxies. Can we find out the distance at which it changed its frequency. So in another solar system, it might seem to be Green ...
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0answers
49 views

Different mass stars orbiting the same distance from galactic center [closed]

We have observed that 'all' stars orbit the center of the galaxy at the same speed. Assuming that we had two stars that are far enough apart as to not interact with each other... (I say this because ...
3
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0answers
94 views

Dark matter “hair” flowing through the earth

Gary Prézeau of NASA's JPL has done some calculations of how dark matter might be focussed by the Earth's gravitational field (publication preprint), and the results show some remarkable hairy ...
4
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3answers
110 views

Why are the jets of the “light saber” star slightly curved?

Why don't the jets of the HH-24 object follow a straight line? In the image below, notice how they bend towards left from the expected straight line. Is it an optical distortion, or some nearby ...
2
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30 views

Why is CO a good tracer for H2? How are those molecules correlated?

One always reads and hears that CO is a good tracer for H2. How are they correlated? How can you deduce from the (measurable) CO the amount of the (unmeasurable) H2 in the ISM?
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1answer
39 views

What is the gravitational power that neutrinos created in the big bang exert on us?

I was thinking about the big bang, and I remembered that neutrinos not only travel at the speed of light, but they were also created in massive quantities very early in the universe (Hadron epoch). ...
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1answer
51 views

If there were infinite many stars [duplicate]

If there were infinite many stars, is the sky then always full of light so is there than even night?
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1answer
61 views

How do fluids behave in space?

In outer space under absence of any external force (like gravity) can a free liquid develop pressure due to cohesive forces? Will the liquid be in spherical shape and will pressure increase towards ...
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0answers
16 views

Origin of the minimum speed formula for relativistic jets

I am studying superluminal motion in relativistic jets. I understand that the velocity of an emitting part of the jet $v$ can be related to the transverse velocity $v_t$ via $$ \frac{v}{c} = ...
2
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1answer
35 views

Direction of Gamma Ray Bursts

After a black hole consumes a star, why do gamma ray bursts only shoot out perpendicular to the spinning accretion disk? Why do they not shoot out parallel to the disk?
4
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1answer
124 views

Why do astronomers call all elements heavier than helium “metals”?

I understand that a scientific term need not be constrained by its etymology. But is there some significant reason why astronomers choose to call all elements heavier than helium "metals"? Are ...