TOI-1227 b


TOI-1227 b is one of the youngest transiting exoplanets discovered, alongside K2-33b and HIP 67522 b. The exoplanet TOI-1227 b is million years old and currently large. It will become a planet in about 1 billion years, because the planet is still contracting. TOI-1227 b orbits its host star every 27.36 days.

Characteristics

TOI-1227 b has a size that is 85% that of Jupiter, or 9.6 times that of Earth. No other Jupiter-sized planet was detected around mid- to late M-dwarfs, despite the deep transits such a planet would create. The researchers find that the planet is still hot from its formation and this heat, combined with a hydrogen-dominated primary atmosphere makes the atmosphere of TOI-1227 b inflated. Evolutionary models suggest that TOI-1227 b will eventually evolve into a sub-Neptune within the next billion years.

Future research

follow-up to determine the mass of TOI-1227 b is not possible in the optical, but might be possible in the near-infrared. A less challenging follow-up would be the measurement of the Spin-Orbit-Alignment via the Rossiter–McLaughlin effect.

Host star

TOI-1227 was first identified as a pre-main-sequence star with the Gaia satellite. Without this prior identification as a PMS star the exoplanet signal of TOI-1227 b would have been disregarded as an eclipsing binary due to the V-shape of the transit signal.
The star is located north of the globular cluster NGC 4372, but it is much closer to earth than this cluster of stars, at a distance of about. NGC 4372 is away.
The host star TOI-1227 is part of a subgroup of the Lower Centaurus Crux OB association, sometimes called B, A0 and called Musca group by the scientists that discovered TOI-1227 b. This group was called Musca after the constellation Musca in which most of its members are located.
TOI-1227 has a spectral type of M4.5V to M5V, a mass 17% of the Sun and a radius 56% of the Sun. The host star is relative faint for a TOI with a visual magnitude of about 17. The right ascension of and the declination implies that it is located in the Musca constellation. The host star shows Lithium in its atmosphere, which should be depleted within 10-200 million years for M-dwarfs.