rebound

For something more rigorous, I would like to take this opportunity to share rebound[1], something we use for n-body simulations in our field (planet formation). Perhaps few people here are already familiar with it. It has a Python interface but the C interface is very easy to use as well and has plethora of pre-set examples which can be visualized using GLFW. It's very very cool! [1]https://github.com/hannorein/rebound

If anyone is interested in playing around with gravitational dynamics I highly recommend the REBOUND library [1]. It has a simple Python interface but under the hood it has a collection of research grade integrators. It came out around the time I was finishing up my PhD in gravitational dynamics, but if I were still in the field it's what I'd be using. If you're curious what would happen to the Solar System if you made Jupiter 10 times more massive you can pip import the library and find out for yourself in about five minutes. [1]: https://github.com/hannorein/rebound

This is some neat research (and related to some of the work I did in my PhD). For those who are just reading the comments, the authors are exploring the impact of general relativity on the stability of the Solar System. It's been known now for a few decades that the Solar System is only marginally stable [1]. The gravitational perturbations of all the planets on each other (though mostly coming from Jupiter) cause the orbits of the planets to change slowly over time. It turns out, though, that Mercury is the closest to unstable, and has a ~1% chance of being ejected from the Solar System in the next billion years. One of the interesting things about Mercury, is that general relativity has a non-negligible effect on its dynamics (the famous "perihelion precession" that Einstein explained). What the authors did in this paper is run a n

Hanno Rein and Daniel Tamayo are pretty legit dynamicists. For anyone interested in doing calculations like these themselves, they've been working on this amazing N-body library called Rebound: https://github.com/hannorein/rebound One of my all-time favorite figures is Fig. 1 of this paper of theirs describing one of the integrators used in Rebound: https://arxiv.org/abs/1704.07715

> But honestly I am certain that it is something in particular and not something mysterious about conservation of energy/momentum which i have not come across yet, because there is no formula in that gravity simulation which should be able to destroy momentum It's a well established fact that numerical integration methods either gain or lose energy (in particular, the Runge-Kutta family is known to lose energy over time). For celestial mechanics simulations, a special class of numerical integration methods called "symplectic integrators" are used and their purpose is to conserve energy and angular momentum. > but if you do any adjustments to correct it, that is a kind of fudge not based in true physics. When you are numerically integrating differential equations that model physical phenomena, you're not doing "true physics" but an approxi

Hey there! I'm a grad student in my last year and my research is in orbital dynamics. I've recently started getting into the rebound package written by Hanno Rein: https://github.com/hannorein/rebound There's some tutorials that come with it. It can also read data from JPL's ephemerides to calculate orbits of various planets and minor bodies in the Solar System. It has a couple of different integrators (some symplectic, some not), but one of them (IAS15) is new and (as far as I know) the best for long-term integrations of Solar-System-like systems. Also if you're interested in studying the long-term evolution of hierarchical triples, I wrote a Python package to study that: https://github.com/joe-antognini/kozai As far as star charts, you can do things like that with AstroPy. If you want the coordinates of stars, look into astropy.vo,

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