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Astronomy Related Programs

As is usual with computer programs being released, these programs are under copyright by me (James Marshall) and I retain all rights related to the programs, other people can't sell them or claim them as their own, etc., etc., all other relevant legal stuff, etc. You get the idea. I guess you could call it free/open source, so I'm not *requiring* any kind of payment. However, if paying for them will make you feel better or if you just *want* to compensate a former student for his work, e-mail me and I'll give you a postal address you can use to mail me money or stuff. Or just check out the other parts of my web site, look for wish lists, and send something that way. ;)

Oh yeah, there's no guarantee that these programs will always give the correct results. You know how it is with programming, there's almost always things to be fixed. I'm pretty sure that the apsidal motion programs are good since I've used them for a few years and had a few publications based on the results they gave. However, things written for classes may or may not be completely correct, some more correct than others, etc. Basically I'm saying that you use these programs at your own risk. :) If you check any of these programs out and do find errors, I would really appreciate it if you could e-mail me and let me know what the problem is (so that I can fix it if I get time) or how to solve the problem (if you've figured out the correction I need to make). Thanks.

If anyone out there is interested, I have some other programs and stuff I've written for classes and other things I've had to do. I used to have program descriptions up here, but since I've almost never been asked about them, why take up extra space? :) If you might be interested in these other programs e-mail me at dronak@yahoo.com and I'll be happy to tell you what I've got (if I remember and can find the stuff). If you can tell me what you're looking for, that would help me out, too.

BASIC Programs

• apsidal3.bas (21k) -- My revision of a program written by a previous Villanova student (Sean Carroll). It basically calculates apsidal motion rates (classical and relativistic) for a system when given the necessary information. By the way, this is number three because I figure the original program was version 1, the revisions I made in summer 1995 updated the program to version 2, and the new revisions made last summer (1996) make this version number 3. I fixed the v*sin(i) option so that it now works correctly (some bugs slipped past unnoticed last time). If you still have an old copy (version 2), please pick up this new version now.
• astclock.bas (9k) -- An astronomical clock. It shows the time in local mean time (12 and 24 hour formats), Universal time, local sidereal time, or Greenwich sidereal time, as well as a constantly updated geocentric Julian Date and an hour angle (when given a star's RA). A bug was found in the program which I have now corrected. Thanks to Bruce Frederiksen for pointing it out to me.
• astclock.txt (20 bytes) -- A required data file for the astclock program. All it has is the conversion *from* UT *to* local time and the user's longitude in decimal degrees. These values could actually be put inside the code if you don't like having another file around. I just thought changing numbers in a file was easier than changing the code and recompiling. The current values in the file are for Villanova, PA. Rename to astclock.dat.
• apsmot.bas (22k) -- The one program that combines o-c.bas, ephem.bas, and calc-apm.bas into one easier to use program. It also adds a few things that aren't in the separate programs, such as uncertainty calculations. The three separate programs can still be useful on their own, so don't get rid of them if you have them already.
• calc-apm.bas (2k) -- This calculates an apsidal motion rate for a system based on observations rather than theory.
• ephem.bas -- This calculates a new ephemeris (T_min and period) for a system based on the observations and some calculations which can be done with the o-c program.
• o-c.bas (7k) -- This program calculates the O-C values (observed - calculated) for observed times of minima along with other useful values like the epoch/cycle number and a value for how far away secondary eclipse is from 0.5 phase (useful in the work I've been doing for stars with large apsidal motions and thus changing phases for secondary eclipse).
• partecl.bas (9k) -- This program uses a simple method for analyzing the light curves of partial eclipsing binaries and gets a good estimate of the values needed for more detailed analysis methods.

Non-Astronomy BASIC Programs

• einquote.bas -- A simple program that randomly selects and prints a quote by Albert Einstein.
• murphlaw.bas -- A simple program that randomly selects and prints one of Murphy's Laws.

C Programs

• minima.c (18k) -- Determines times of minima for any variable system (given an initial time of minima and a period) for any phase.
• sunmodel.c (24k) -- Makes a simple model of a Sun-like star (i.e., up to about 3 solar masses at which point the approximations used in the program start to break down). If you're interested in knowing more about how this program works, you can look at the description I wrote up about the calculations and theory involved. I am aware that this calculation method is probably not the best way of doing it, but it served my purposes well enough and I haven't had time to play with it to try to make a better version.

TI-BASIC Programs

• date2jd (1k) -- Converts calendar date into Julian Date.
• jd2date (1k) -- Converts Julian Date into calendar date.
• kappa (4k) -- Computes opacities, flux, etc. for a stellar model.

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