Current project: Modified Stargen (a solar system generator)

[omega13a]

Basically what this is is a modified version of Stargen that was discussed in this topic: viewtopic.php?f=8&t=16807

The most important changes have to do with radii and densities of the planets/moons generated.

All the solid worlds are now made out of some combination of iron/rock/ice.

All the jovians and brown dwarfs now have radii that are more or less based on data I found in this research paper: http://www.ucolick.org/~jfortney/papers/Fortney07.pdf

I have hopefully solved the problem of gas dwarfs and sub-jovians having ridiculusly low densities (like 1/3 that of water) when they are located in the outer reaches of the solar system.

As I do not have the means to build binaries for Windows (I use Linux), I have only provided the source code so if anyone can build the Windows binaries for me, I will greatly apriciate it.

You can download the source code at http://fedtrek.com/staff/omega13a/stargen_2013.zip

This is still a work in progress and any feed back and improvents are welcomed.

[Reiko]

Has anyone built this for windows yet? I have no idea how to do it.

[omega13a]

I was able sneak onto my dad's computer after he went to bed and installed cygwin and built the windows binaries. My dad is really sensitive about me using his computer. He's afraid I'll skrew it up. Truth is, he has skrewed up four computers, wrecked three calculators (all of which he borrowed from me), wrecked one networking hub, busted two sissors, infected one of his company's local network with a virus by opening a supicious email, and broke the sliding door to our patio twice simply by opening it. In short he's far more dangerous than I am. Anyways, I tested the binaries and they appear to work on my dad's computer. Don't know about anyone else's so please let me know if they don't work.

You can download the binaries at here: http://fedtrek.com/staff/omega13a/starg ... naries.zip

[Reiko]

I cannot get it to work. It first says I need cygwin1.dll and once I have that it gives me another error code...
The procedure entry point_ctype_ptr__could not be located in the dynamic link library cygwin1.dll.

[Chuft-Captain]

You can download the binaries at here: http://fedtrek.com/staff/omega13a/starg ... naries.zip

After what you've just told us about your father, I'm not going to touch anything that's come from his computer!

[omega13a]

I cannot get it to work. It first says I need cygwin1.dll and once I have that it gives me another error code...
The procedure entry point_ctype_ptr__could not be located in the dynamic link library cygwin1.dll.

I added the dlls that was in selden's mcl2stc zip file. Try it again.

After what you've just told us about your father, I'm not going to touch anything that's come from his computer!

Don't worry, if there was a virus in the zip file, I seriously doubt the zip file would still be on my webserver after last night's virus scan.

[selden]

FYI: My understanding is that Cygwin's license requires that if you include their DLLs, your product must be released under the GNU license, which, among other things, requires you to provide full source code. See http://cygwin.com/licensing.html

[Reiko]

YAY it works now, thank you.
Unfortunately I don't know how to use it since it's command line.

[omega13a]

The information is in the help folder that comes in the zip package.

[John Van Vliet]

--- edit ---

[omega13a]

I'm slowly getting a new version ready. This next version has three new types of planets: iron, carbon, and oil (basically the same as carbon but has liquids on its surface). I need to run a few more tests due to a bug that causes rocky planets to be way more dense than iron planets...

MinGW? I just looked that up and apperently I can use it build windows binaries under linux. I'll try that. Hopefully it will work.

[Tegmine]

Will I be able to set AU limits in the modified version? I would like make some systems for binary systems.

Thanks

-M-

[omega13a]

hmmm... It might be possible for me to add that though I'm going to need to make a list of letters and numbers that aren't used as arguments since most of them are currently used... I'm also thinking of added support for spectral types since the a star's spectral type appears to affect the albedo of gas giants though that would be easier if this was in C++ because I find working with strings a lot easier in C++ than in C.

[PlutonianEmpire]

Will I be able to set AU limits in the modified version? I would like make some systems for binary systems.

Thanks

-M-

Hey, I've been fiddling around with the 2013 version from the OP, and while I'm sure you and others may have noticed, I think it might be interesting to note that it already does a good job for circumbinary systems with tight-knit binaries such as the latter Kepler circumbinaries, when entering the system parameters for the custom mass and luminosity. The "p1" planets are almost always given a Mercury-like orbit, with a huge gap between it and the central star or barycentre.

Case in point, I ran ten iterations for DEL Tri, and with the custom .stc file I've had for that system, the closest planet has a SMA of 0.3728 au, and the AB separation is just over 0.11146 AU, meaning p1 is over 3.34 times the AB separation from the center of the system. And as Kepler data seems to imply, a "rule of three" seems to be in play in terms of orbital stability versus p_a:AB_a ratio, and ejecting (or consuming) planets with SMA less than 3x the AB separation.

Anyways, question: I've noticed that the program can generate planets en masse around a number of fictitious star sets, such as Cham's Ring Universe. Were the source files (.c and .h files for use in stargen) generated with an utility; or were they written manually (the stars entered one by one, line by line, by hand)?

[omega13a]

I made them using a utility I have laying around somewhere... As for when the next version is going to be released, I'm trying to incorporate some calculations from another research paper I found.

[PlutonianEmpire]

Question: I've noticed that when I include gases when generating systems, they are measured in percentage and "ipp". Is the latter a typo? If not, what does it mean and/or stand for, and is it similar to PPM, parts per million?

And how do I calculate both PPM and IPP?

[omega13a]

IPP is short for inspired partial pressure. I don't know much about what it is other than it is used to determine the breathablity of the atmospheres.

[omega13a]

I got a new version working at least for me. Its takes into account the spectral type and temperature of stars when generating systems so the habitable zones and albedo of the gas giants will be more in line with current theories. I also managed to more or less translate selden's moon generator code from fortran into a language I'm more familiar with which allowed me to splice it into stargen so you don't have to run it separately.

I don't have any binaries for windows so you will have to compile the code for one. Anyways, here's the link to the new version:

http://www.fedtrek.com/staff/omega13a/c ... n_2014.zip

[omega13a]

More changes made to the program. It now takes into account the albedo of vegetation on habitable worlds. I also made the filter for habitable worlds a little more stricter by excluding any planets around type O, B, and A type stars since they don't live long enough in the real world for life to form on any of their planets based on our current understanding of things. You can still download it from http://www.fedtrek.com/staff/omega13a/c ... n_2014.zip .

As usual, please tell me of any bugs or problems you have with it and I'll see what I can do.

[PlutonianEmpire]

I dunno if it was changed in the new 2014 version, but my biggest issue was with the -J option, which forced jovians to be in the habitable zone. My issue with that was, the "jovians" weren't jovians at all -- they ALL were ONLY upper-level super-earths and mini-neptunes. I NEVER got anything that was truly jovian -- aka, Saturn- or Jupiter-mass or larger. The only way I could figure out to get true jovians in the habitable region was to not use any of the habitable-zone-related options, which meant simply not using -E, -H, and -2 and -3, and just crank out thousands of systems at a time into ssc files and hope to find one by pure chance.

And my other issue was, lack of support for circumbinaries, for Earthlikes and Habitables/Breathables. Best way I can think of off the top of my head, since Binaries tend to have inflated masses over the luminosities, when treating both components as a single star, would be an option that allows an exception rule for the Earthlikes and Breathables filters, so the filter doesn't mistake a 1.8 mass "sun" with a luminosity of 1.2 as being too short-lived for habitables. (Entering 1.8 Msun onto the "main sequence star" page at archive.org gives me a luminosity of over 8.6).