UROS 2018 Projects: Numerical Constraints on a Potential Embedded Exomoon in the J1407b Exoring

by Felicity Levett

Warning. The following is brutally honest.

Firstly, how do I think my UROS went? Pretty bad. However, I learned a lot! A lot about my own skills and attributes. A lot about planet J1407b. And a lot about the horrors of using C++.

Let me start with what I actually had to do. The project was called ‘Numerical Modelling of the Exoring System Around the Exoplanet J1407b.’ Planet J1407b can be found near the Centaurus constellation, approximately 433 light years away. That is 4.10×1018 metres, which is an unfathomable number. The planet’s “funky name” is an exoplanet, meaning it orbits another star other than our own. Like our planet, it is theorized that J1407b has a moon. Only this moon carves its way through a ring system, 200 times larger than Saturn’s!

As this moon whips around the planet, it creates a gap width. Using this gap width, I was then able to create a program on C++ which determined the mass of the moon needed to create this. Out of my three tasks, this was the one that cause the least tears…

Following this, I created a plot of gap width against the mass of the moon. To summarise, as expected, the larger the moon, the larger the gap in the exoring it creates. One of the problems with creating a graph on C++ is that the scaling can be a bit too large. This means that when looking at the graph, you can see a general trend, but not individual values accurately. So, although C++ is great for quickly doing repetitive calculations, graphs are not its strong point… Although, it could be my skills still needing improvement!

The final task was to create another graph of the orbital period of the moon at 0.4AU away from the planet, with respect to the mass of the J1407b. This ensures that the approximation for the size of the planet is correct. The graph created was as to be expected, however rather than being linear, it appeared as a more inversely proportional logarithmic curve.  On the other hand, this shaped curve could be a result of a scale, not suitable for the data.

Though the graphs were not as colourful and snazzy in comparison to if they had been created on Maple or Matlab, I was still immensely proud when I successfully received an output from programs. C++ is an important language to learn in relation to coding. Computational work is a key skill to learn and improve on if considering working within any industry, after completing a degree in Physics. Moreover, in my course, a lot of the work is computationally based. This project allowed me to exercise the skills I learnt from the course of my second year and strengthen them ready for my final year.

So, did I find UROS helpful? Yes. Yes I did.


*To view Felicity’s project poster, please click on the thumbnail below: