Hello to all Please Register or Log in to view the hidden image! I was designing a star system, that features an inhabited planet, as part of a personal "fictional universe" project. I was looking for a random sun-like star as the home of the planet, and the point of origin of the life forms the planet featured. I had picked it up some time ago when the biosphere was just a concept of a few sentences inside my head. As I have added a lot more details and complexity to it, i was thinking of researching the star system, to see how plausible is it to host a planet like the one I imagined. The star system in question is HD 45184 (referred to as 'Corum' in my fictional universe). What I was initially looking for was: * Possibility of hosting rocky bodies; * Corum being slightly larger than the Sun, and shining more brightly since the planet (called Arcadius) is receiving a bit more heat and light than the Earth does; * Arcadius having violent megaquakes and meteor showers creating an extinction level event at some point in its history, as a result of external factors; * Arcadius having large oceans as well as oxygen and ozone-producing life forms. Information about the star was poor (to say the least), until recently, when more information and data was released about it together with the discovery of a large planetary body, almost the size of Neptune, orbiting in a very close orbit around the star (0.0638 AU), earning it hot Super-earth candidate status. The star is similar to the Sun (G1.5V), a bit larger mass and radius, slightly more luminous, temp. slightly higher than Earth (5869 K), and metallicity higher than the Sun, ranging from 110% to 140%, and its age is 4.1 billion years. Most of the data above seem to fit with the characteristics I have prescribed to the system without even knowing anything about it other than its spectral class (at the time thought to be G2V). I guess I was lucky. Now, I have a few questions, and would very much appreciate the answers: 1) Does anyone know more about planet migration? Especially migration of giant planets? I was thinking of using the giant planet that's discovered as the reason behind the megaquakes and meteor showers that gradually cause an extinction level event on the planet in its distant past. - Is a body the size of Neptune large enough to cause such effects on smaller worlds such as Arcadius, like the quakes and also large enough to hurl comets and asteroids towards the planet? Without having to be too close for the two planets to crash into each other? 2) This star system has an unusually high abundance of yttrium and barium compared to our Sun (barium reaching 44% more than the barium presence in our solar system) - Would this mean that I could incorporate it somehow in some quantity in the biosphere or the atmosphere? - Is there any organic molecules that can chain yttrium and especially barium? I'm just curious as to the possibility, I can surely go without them. 3) The oxygen-to-hydrogen ratio is 23% higher than the oxygen-to-hydrogen ratio in the sun. What does that exactly mean? Sorry if its a stupid question, but I'm not sure what to take from it. - Does this mean hydrogen and oxygen are 23% more present in the chemical soup the star system was made of, than the sun? Would that mean 23% more water? It would surely fit with Arcadius having more water, and life forms that produce a lot of oxygen. I appreciate any well-intentioned input. Thank you Please Register or Log in to view the hidden image!