Stellar Definition and 176 Threads

How far away is the average star in the night sky? I mean, can we see stars that are on the other side of the galaxy? Perhaps most of the visible stars are maybe just a few dozen light years away?

I seek a suitable and current graduate level text on astronomical spectroscopy. The desired emphasis is on stellar sources. I would appreciate recommendations.

Hello I am a student in high school and my physics teacher is a complete idiot. He just gave us a project to draw the life cycle of stars without even teaching the class. I am completely lost. Can someone help me draw the life cycle of stars that includes small: G-yellow K-orange...

Hello, In the process of revising for an exam I have, I am having difficulty with this question. "Consider an isotropic stellar wind of mass density rho, pressure p, temperature T and velocity v that has reached to a distance r=R_w from the centre of a star. The star has mass M* and...

I am new to astronomy, though really interested in it Just read up on stellar evolution from multiple sources, but have some questions about it Let me summarize the theory of stellar evolution 1. gas clouds collapse due to multiple mechanisms, e.g. shock wave, collision of clouds... 2. the...

Hey folks, I'm currently at grad school and am working on an algorithm to try and model the rate of supernova (type I and II) in our galaxy. I really need to know the following information. 1) Where can I find information on HOW MANY of the different types of stars there are in our...

http://www.cbsnews.com/stories/2006/12/22/politics/main2292806.shtml The correspondence is posted online: http://www.attrition.org/postal/z/033/0871.html

I'm interested in the prehistory of the history of relativity. In this history the nature of light and the ether comes in. One phenomenon that was debated in this context was stellar aberration: that the positions of the stars in the sky change slightly, or, more precisely, the perceived...

On reading Vilenkin's recent paper, I believe he fails to refute the CNS conjecture. This is for a very simple reason. When Smolin has discussed the conjecture he has made it clear that it concerns black holes formed by stellar collapse. Vilenkin confuses the issue by attempting to switch...

Hey, would anyone be able to tell me quality websites/ or help to answer the following questions: 1. What is a star? 2. How Astronomers can tell the difference between different stellar objects? 3. What powers a star? 4. The evelotionary path of a star and it's different stages. 5. Why...

Hello there! I'm developing a "4x" game a-la Master of Orion. I was coding some algorithms to help me generate a somewhat realistic galaxy. I'd like to know if it is possible to compute the time that a main sequence star will spend in its subgiant and giant status. For example, given the...

Hey everyone. I am working on a planetary simulation model and am having a bit of trouble with the math. Given the volume and density of a particular planetary body, how do I calculate the mass? Once I have the mass, how do I calculate the orbital distance of a satellite body to said panetary...

Stellar evolution modeling is a science that, to put it charitably, plods along. Here is one of the more interesting papers I've seen in awhile: http://www.arxiv.org/abs/astro-ph/0601502 Stellar evolution of massive stars at very low metallicities

Why don't stellar spectra show absorption lines for carbon, oxygen or nitrogen if they are such abundant elements. Is there a 'spectral type' that does? Thanks Dave

Astronomers announced that stars have a size limit. What does it say about stars' cores? This is still unknown i'd say. Btw a new yellow star was discovered outside the solar system. Looks very much like our sun.

http://www.cococubed.com/code_pages/codes.shtml Some journal articles available.

Hello, all I have just read some foundamental concepts about EM spectrum in astronomy. One thing I don't quite understand is that "Stars with higher temperature or higher pressure shows a broadened line on its absorption spectrum". A brief explanation states that a higher temperature or...

how can i calculate the fractional abundance of HI, HII, H- and e- for hydrogen in the photosphere (T=5770K) and density 10^17?

Hi there. I'm new to the field of astrophysics so if my questions are a bit silly, don't mind saying it. 1. What is the relation between the luminosity/colour or a star and it's mass? 2. What is the relation between luminosity/colour and life expectancy (I know brighter stars die...

Seems that not much gets posted here lately. The link is to a simple chart that answers (in advance) some of the questions asked here. Note in particular the abundance label at the bottom of each class, with M Class stars being 80% ! See how few of the biggies (Class O, B and A) are either...

I'm trying to teach myself some of the early basics of stellar modelling and hope to write some code to calculate conditions within the star Assuming a constant and homogenous composition and simplified calculations of pressure equation of state and opacity. Simplified assumption of...

Neutron Stellar Cores... I watched a program in which a astrophysics professor suggested that in theoretical calculations, a Trans-Oppenheimer Neutron Stellar Core's acoustical velocity can exceed vacuum luminous velocity. v_s >= c Oppenheimer Neutron Stellar Density: p_n = \frac{3...

I am trying to write some code to produce a model of a star. I've done loads of research and come to the conclusion that for ease i want to represent the opacity in my model with the power law. k=k(0)*(rho^alpha)*(T^beta) this seems very straight forward apart from the fact that in every...

Hello I'm in the process of writing some code to enable me to solve for the stellar structure and evolution of a star. Langauge is C++, unfortunately my coding isn't exactly up to scratch and i was wondering if anybody has any useful hints or tips. I'll attach a copy of my source code. I...

In the “ Theory development ” forum I develop my theory of a general origin of all fundamental forces. As an example of practical application of this theory I have developed the table of spectra of radiation of stars and fogs in dependence from a value of their magnetic and gravity...

can anyone tell me what the latest theories are for inter stellar propulsion, and has the problem of bone loss on long space flights been solved?