# What is Astrophisics: Definition and 27 Discussions

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1. ### I enjoy complex problems in science

Male in my twenties, enjoying hard problems in engineering, mathematics, and physics.
2. ### B Nuclear Fusion in the Singularity

Would it be possible for Black Holes to undergo nuclear fusion of materials with very high atomic numbers (above 118 or the majority of known atoms) in their singularity, producing any signs, including photons across the spectrum? Furthermore, I was thinking aloud and wondering, what prevents...
3. ### Decrease of Solar radius per year using Virial Theorem

Hello, I am trying to solve this question: Assume that the Sun's energy production doesn't happen by fusion processes, but is caused by a slow compression and that the radiated energy can be described by the Virial Theorem: $$L_G = - \frac{1}{2} \frac{GM^2}{R^2} \frac{dR}{dt}$$ How much must...
4. ### I Brightness and solid angle

I have a doubt regarding the role of the solid angle when calculating the power(W) with the brightness of the source I'm observing with area Asource. I was given the definition: with A the Aantenna. If now I take as an example the picture below to calculate W, we conisder as solid angle the one...
5. ### Why is the degeneracy criterion the same for all stars?

Is it anything to do with the equation being independent of mass etc.. of the star? or to do with the Pauli exclusion principle? Any help will be much appreciated.
6. ### Path of an electron from the Sun to the Earth

Let's suppose a solar electron moving directly towards Earth's equator at a high speed. This electron meets Earth's magnetic field, which points to the north, at a distance ten times the Earth's radius, where magnetic field is almost uniform. Which will be the direction this electron describes...

8. ### Astrophysics/Astronomy Extended Essay -- Trying to figure out a research topic

Homework Statement: Ideas for astrophysics EE Homework Equations: Extended essay Hi Guys! I'm trying to figure out a research topic in astrophysics/astronomy for my IB extended essay. I don't really know what to do, do any of you any ideas, maybe even off the top of your heads? It needs to...
9. ### I Free Orbit Insertion: Is it Possible?

Good evening, This week I had a discussion/conversation with one of my coworkers about the posibility of a mass from outer spate that could start orbiting the earth. The issue is, I believe you cannot, whithout a proper change of energy (velocity) start orbiting a celestial body just by coming...
10. ### How can I determine the inclination degree? (visual binary)

Problem Statement: When I can observe the orbit of visual binary,How can I determine the inclination degree?? Relevant Equations: Keplar's low?? But now, we know the distance to the binary(45.9pc), and viewing radius(1.2mas).
11. ### Calculating Apparent Semimajor Axis: A Unit Conversion Challenge

Hello I think this image's calculation is wrong. I cannot convert units(What is arcsec??How convert to pc??) How do you think ??I would like to see your calculation process. I'm so grad if you show.
12. ### I Black hole orbital mechanics questions

What are some of the challenges associated with calculating orbital parameters of objects around a black hole (I.e. Orbital velocity, period, semi major axis, kinetic energy). At what point can classical physics no longer provide accurate results?
13. ### I What does this description mean? (two bodies orbiting each other)

Hello, I'm reading a textbook named "Introduction to Rocket Science and Engineering" by Travis S. Taylor. I'm now in a general cosepts about orbits. I have a question, what the book says in here? I can't understand the bold formatted sentence. What the author try to mean? If you can, can you...
14. ### Accretion rate onto a WD over time (relation)

Hi all, I was wondering if there is a correlation between the accretion rate and time. I think it should decrease as time increases, but I can't find the right correlation
15. ### I Is the universe spherical and shaped like a bubble or is it flat?

Could the universe have been created by the collision of two older universes with the same dimensions? Could the expansion we observe be caused by these two universes still merging like boubbles coming together and the resulting increase of gas makes the film grow larger?
16. ### What is the largest possible Rotating wheel space station?

What is the largest possible Rotating wheel space station possible to be constructed with current materials? and what would be the population it would support. also formulas used for calculation.would be useful. Could constructing cylindrical space elevators support more population,
17. ### Why doesn't SNEC work with my profile?

Hello, I have made a python script that splits my desired star.data file from a MESA model into two distinct files that I need to use in SNEC link here: https://github.com/abostroem/SNEC My script is here : https://github.com/ilaur/SNEC-Split When I try to run SNEC with my custom profile it...
18. A

### What are the Three Main Sections of PF for Science Enthusiasts?

This is Ashwani, newly joined this beautiful forum. I am a mechanical engineering graduate with MBA in operations management and working with a manufacturing company in India. Thanks, Ashwani Dusadh
19. ### I Energy Transport in Stars

I'm trying to understand why convection is an efficient mode of energy transport in the outer layers of the solar interior. Could anyone give me a little bit of knowledge? Thank you!
20. ### Researching & Publishing a Physics Paper as an Undergraduate

Hi ! I want to do research and publish a research paper on a topic related to physics . I am an undergraduate student , but I am much interested in research work. Kindly suggest me a topic on which I should do research ? And how much time will it take for the complete my research work ?
21. ### Deriving the formula for tidal generating force TGF

i have been asked to show that the TGF acting on a 1kg mass, on the surface of the Moon is equal to: TGF = 2g.e^2.(a/r^3) Where; g = 9.81 e = radius of the Earth a = radius of the Moon r = distance between the centres of the Earth and Moon.
22. ### I Difference between oscillatory/cyclic model and big bounce?

If a Big Bounce can occur "after a universal singularity is reached or a repulsive quantum force causes re-expansion" then what differentiates it from oscillatory/cyclic models if both of them defend that the universe will re-expand from a singularity or before that...
23. M

### Best Transfer Options for Astrophysics Major in California?

Hey! I'm currently a student attending community college as an Astrophysics major. I'm looking to transfer after spring semester of next year (which is going to be my third year at the cc) And I was wondering what are some calstates or even some UC's that I should look into. My gpa is okay right...
24. ### What jobs are available to an Astrophysics Student?

Hello, I am a 19 year old female who just graduated from a community college with an Associate in Science degree. I chose to major in physics and am planning on continuing my degree this Fall at a University. My issue is that I want to go into the Astrophysics field, but I am greatly worried...
25. ### A What is stochastic heating of very small grains?

I recently came across a paper where there was a term ''stochastic heating of very small grains". I went through some papers on this area but I am still confused about it. What is the vibrational temperature associated with very small grains? Does temperature has got a meaning if it's a highly...
26. ### Other Should I research outside of my school?

Currently I am at the University of Texas at Arlington where I am studying the physical and chemical properties of supernova remnants to figure out the state of its progenitor star. Now, I was thinking of going someplace else to research for the summer, not because I am not interested in the...
27. L

### Interested in thermodinamics, quantics and astrophisics

My name is Liviu Marinica, I was born in Romania, and I am an 48 yo electrical engineer. My background in engineering is related to office work (design) but also field service work for electrical power equipments such as medium and low voltage switchboards, protection relays (called IED, or RTU...