The Orion's Arm Universe Project Forums





Exoplanet Discoveries and Updates
#56
There is a possible detection of Proxima c through direct imaging. Doesn't appear to be consistent with the astrometric solution to the planet's orbit, but does seem to line up well with the previous paper and ALMA observations. The object's semi-major axis is slightly closer to the star than Proxima c from previous work, at 1.4 or 1.33 AU depending on eccentricity, the latter yielding a lower value for Proxima Centauri's mass, at 0.091+-0.012 solar masses, than the current 0.12 solar masses. Finally, the object appears to be too bright, meaning there is a possibility of circumplanetary material such as a ring system or a dust cloud produced by collisions.

====================

Further out, 130 light-years from Sol, we have TOI-1235 b (paper 1, paper 2), a hot rocky planet orbiting around an early M-type star whose radius puts it in the middle of the Fulton gap - the zone spanning from 1.5 to 2 Earth masses where planets usually become larger through the accumulation of hydrogen and helium or smaller through the loss of aforementioned elements. The paper also mentions another candidate planet, more massive with a minimum mass of 13 Earths and further out at 0.1319 AU.

TOI-1235 b
Semi-major axis: 0.038 AU (calculated by myself, using star's mass cited in the second paper at 0.640 solar masses)
Orbital period: 3.44 days
Mass: 6.91 Earths
Radius: 1.738 Earths

====================

Finally, reanalyzed data from Kepler revealed Kepler-1649c, an Earth-sized planet in the habitable zone of a red dwarf star, very similar to TRAPPIST-1e, although a year on this planet lasts 19.5 days rather than 6.1 days, as its star is more massive, at 0.1977 solar masses. Kepler's previous closest match was Kepler-186f, an Earth-sized planet lingering at the outer edge of the star's habitable zone. The system has another, previously known planet of similar size in closer orbit that gives it Venus-like irradiance. The two planets in this system are linked in a 4:9 mean-motion resonance. The system is roughly 300 light-years away from Sol.

Kepler-1649c
Semi-major axis: 0.083 AU (calculated by myself, using star's mass cited in the paper at 0.1977 solar masses)
Orbital period: 19.5 days
Radius: 1.06 Earths
Irradiance: 0.74 Earths
Reply


Messages In This Thread
RE: Exoplanet Discoveries and Updates - by The Astronomer - 04-16-2020, 09:40 AM

Forum Jump:


Users browsing this thread: 3 Guest(s)