What are the major unsolved theoretic problems on the dust molecular clouds?

I wonder if we can list direct methods to solve the optimal control problem. I would start with:

1. Steepest descent method

Can anyone add more? With appreciations.

Is there any tips or article references as to easily investigate the connecting loops from AIA 171 angstrom by using eyes, as to determine the polarity of the sunspots as trigerring the flares?

Can anybody please share the IDL source code for Hapke photometric modeling?

Thank you,

Astrophysical S-factors for thermonuclear reactions that produce electron neutrinos.

We know that the equilibrium condition for neutron star. But I do not know in the case of hyperon star. Is it same or not?

This question is directed to observational astrophysicists. I am working on the radiation problem associated with massive star formation. I want to know if the opacity of the gas in molecular does vary with distance from the center of a molecular clouds. I see that in the literature this opacity is assumed to be a constant taking a value of about 20 m^2/kg. I will be happy to get an answer from you!

See attachment!

There are several papers which are using following formula (as shown in the picture) to calculate the dust mass (Md) of the dusty environments such as Nebula, loops etc in the ISM. The expression for dust mass shows that it depends on grain size, grain density and grain emissivity, here, for IRAS Survey, grain size = 0.1 micron, density = 1000 kg/m3 and emissivity = 0.0010 for 100 micron, respectively, are used. Are these constants same for AKARI and WISE survey too? OR, are there any other methods for the dust mass calculation using AKARI and WISE data? I would be very much happy to get your valuable suggestions. Thank you :)

A three-dimensional (3-D, nonplanar) geometrical configuration of astrophysical fluids could be conveniently visualized.

What is a justified way to visualize one-dimensional (1-D, planar) geometrical configuration of dust molecular cloud fluids in astrophysics?

What is well represented by the single spatial variable, x, in this context?

When considering bending modes for linear polyatomic molecules containing hyperfine structure, how does increasing the vibrational state affect the various molecular parameters involved in calculating the hyperfine energy levels?