TOI-560c
Mini-Neptune Exoplanet
In a solar system far, far away… 103 light years to be exact, we find our desired exoplanet. As the name suggests, our TOI-560c is not the only exoplanet in its solar system. Although small, the system contains a second planet at aproximately twice the size, named TOI-560b. Both of these orbit around a K-Type star TOI-560, outside the habitable zone of the solar system.
Appearance
According to exoplanet catalogs www.exoplanet.eu and www.exoplanets.nasa.gov TOI-560c is portrayed as orange. However, with TOI-560 being a K4V type star and TOI-560c probably having a thin atmosphere, we rather think that the color may be caused from the color of the star and the light it emits. Because the TOI-560 has a vibrant orange color and therefore this color would be reflected on TOI-560c.
Planet Size
We first calculated the planet diameter to be 30550,62 metres. with a transit depth of 0,01372% Now, when it comes to the radius calculation, we first took the Allesfitter multiplier of 2,395. That gave us a radius of 15 275,3 kilometres. Now with a formula of
with H being the light curve difference we took from Cheops light curve measurement graph, which was 99,862, meaning the difference added up to 0,137. From that we got the multiplier of 2,646, which gave us a radius of 16 752,7km, about a 10% difference from the primary Allesfitter output.
Orbit lenght
We know TOI-560c has a day period of 18,87 Earth days, therefore there is not 365 days in a year, but only 19,35.
In the solar system, both planets orbit very close to their star. So close in fact, that the highest orbit is much lower than the orbit of Mercury in our Solar system. Since we know the distance of TOI-560c from its star, we can calculate the orbit length to be 117 106 752,8km. And from the length, we can determine the orbital velocity as 720958,63 m/s.
The orbit of both planets is similar in terms of inclination, which reaches only a 0,4 irregularity from 90°. Both planets B and C have a very similar orbit inclination, therefore we can say they arent traveling planets which would find their way into this solar system and stay there because of the gravitational pull, but that they were rather created at a very similar time.
TOI-560 Solar System
TOI-560c is not the only planet from its solar system. A second planet orbits around TOI-560. Both were discovered by the transition method. Furthermore, TOI-560b and TOI-560c share nearly indentical inclinations at almost 90 degrees from our viewing angle, further proving that they were created at a similar time in the past. However, there are some differences. Mainly in size and orbital courses. TOI-560b orbital period is at half of TOI-560c with 6,39 according to exoplanet.eu. TOI-560b is measured at 0,249 Jupiter size, while TOI-560c is only 0,23. In terms of colors, there are some differences as well, we made a few hypotheses about the chemical composition of TOI-560c which directly lead into the color scheme, all is mentioned in the „atmospheric hypotheses“ tab. Both planes are also far outside the the habitable zone.
Atmospheric Hypotheses
The difference between a Mini-neptune and a Superearth definition are at a thin border here. We made three hypotheses about how could the composition of TOI-560c look like depending on elements it is composed of and also depending on the thickness of each layer.
In this hypothesis, we thought of the planets core as hydrogen that acts as a solid material. The core would have a diameter of 8000 kilometers. Could there be water? Yes. At the exact pressure of 246MPa, which would allow for water to be in a liquid state. Now, when we would think of the upper atmosphere as indentical to Neptune, that would be a viable option, but the density of TOI-560c would exceed our measured density. Therefore we thought about a new element or compound that would be contained within the atmosphere. This chemical would be a little bit dense than the hydrogen, helium, methane and ammoniac that together create the atmosphere of Neptune.
In this hypothesis we thought of the core as of being made out of aluminum. The atmosphere would be consisting of helium and hydrogen. With a pressure of 26MPa we could see water there with an advantage over hypothesis 1 in this case, because the pressure would be significatly lower, therefore creating much more suitable conditions for any potential probe to be sent there. We also assumed the diameter of the radius as 5200km to match up with all the compounds and the density. In this case the atmosphere could be thicker than in hypothesis 1, as the core does not take up so much space.
In this last case, the atmosphere would consist of helium and hydrogen. The main difference is in the core, which would contain lithium a phosphorus coating. This would make for a great source of lithium batteries. However, we wanted to lower the pressure, so we thought about leaving water out of this hypothesis. Without any water, the pressure could be at 13,6 kPa, the lowest of all the options. After many calculations, we estimated the diameter of the core at 6202,7km.
Our video
TOI-560c Age
According to http://exoplanet.eu/ our exoplanet is rather young at 750 000 000 years of age. At this age Earth was still in the Precambrian era, meaning only organic clusters were forming into prokaryotic cells, from which eukaryotic cells evolved. Although during the Precambrian era the surface temperatures reached only a few degrees above 0°C.
But what about TOI-560c? The surface temperature was measured at around 225 , therefore not a very habitable environment in comparison to Earth. Although we could speculate about thermophilic cells with extra thick cell walls that have adapted to these temperatures. For example near Kavachi volcano on Earth, the water temperatures reach around 68°C and there still are shark species living there. But for TOI-560C we limited our suggestions to only small organisms, which are still very inprobable, depending on the atmospheric contents and pressure.
But what about TOI-560c? The surface temperature was measured at around 225 , therefore not a very habitable environment in comparison to Earth. Although we could speculate about thermophilic cells with extra thick cell walls that have adapted to these temperatures. For example near Kavachi volcano on Earth, the water temperatures reach around 68°C and there still are shark species living there. But for TOI-560C we limited our suggestions to only small organisms, which are still very inprobable, depending on the atmospheric contents and pressure.
Star Comparison
We compared TOI-560 and our Sun. In the compared statistics, Sun came on top in every single one.
| TOI-560 | Sun | |
| Age | 750 milion | +3 853 milion |
| Mass | 1,4515 ×10^30 |
+27% |
| Radius | 452 200km | +35% |
| Star type | K4V | G2V |
| Temperature | 4 240 | +30% |
| Magnitude | 9,67 | -4,84 (more luminosity) |
Star Comparison
Team Planeterra
Simon
klinga.simon@gyby.cz
Karel
photo.horak@email.cz
Tomáš
dvorak.tomas@gyby.cz
Sources
Exoplanet Catalog | Discovery – Exoplanet Exploration: Planets Beyond our Solar System, [no date]. Exoplanet Exploration: Planets Beyond Our Solar System. Online. Available from: https://exoplanets.nasa.gov/discovery/exoplanet-catalog/
The Extrasolar Planets Encyclopaedia — Diagrams. (n.d.). http://exoplanet.eu/diagrams/
The Extrasolar Planet Encyclopaedia — HD 73583 c. (n.d.). http://exoplanet.eu/catalog/hd_73583_c/
The Extrasolar Planets Encyclopaedia — Diagrams. (n.d.). http://exoplanet.eu/diagrams/
The Extrasolar Planet Encyclopaedia — HD 73583 c. (n.d.). http://exoplanet.eu/catalog/hd_73583_c/