Stellar Definition and 163 Threads

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...

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...

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?