TOI-1227 b

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.

Radial velocity 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.

{{Starbox begin|name=TOI-1227}}

{{Starbox observe

|epoch=J2000

|constell=Musca{{Efn|Obtained with a right ascension of {{RA|12|27|4.31}} and a declination of {{DEC|-72|27|6.5}} on this [https://djm.cc/constellation.html website].|name=Constellation|group=note}}

|equinox=J2000

|ra={{RA|12|27|4.31}}

|dec={{DEC|-72|27|6.5}}

|appmag_v=17{{±|1.133}}{{Cite web |title=TOI-1227 {{!}} NASA Exoplanet Archive |url=https://exoplanetarchive.ipac.caltech.edu/overview/TOI-1227 |access-date=2024-02-14 |website=exoplanetarchive.ipac.caltech.edu}}

}}

{{Starbox character

|type=Pre-main sequence star

|class=M4.5V-M5V

}}

{{Starbox astrometry

|radial_v={{Val|13.3|0.3}}

|prop_mo_ra={{Val|-40.2658|0.0972}}

|pm_footnote=

|prop_mo_dec={{Val|-10.6417|0.0807}}

|parallax=9.9079

|p_error=0.0558

|parallax_footnote=

|dist_ly={{Val|328.089|1.87|1.845}}

|dist_footnote=

|dist_pc={{Val|100.641|0.573|0.566}}

|absmag_v=11.986{{Efn|1=Calculated using an apparent magnitude of 17 and a distance of 100.641 parsecs in the equation M{{sub|app}} = M{{sub|abs}} - 5 + 5 * log(distance (parsecs))}}

}}

{{Starbox detail

|mass={{Val|0.17|0.015}}

|radius={{Val|0.56|0.03}}

|luminosity=0.0251

|gravity={{Val|4.7893|0.0058}}

|temperature={{Val|3072|74}}

|rotation={{Val|1.65|0.04|ul=day}}

|rotational_velocity={{Val|16.65|0.24}}

|age_myr={{Val|11|2}}

|source=

}}

{{Starbox catalog

|names=2MASS J12270432-7227064, Gaia DR2, 5842480953772012928, Gaia DR3 5842480953772012928, TIC 360156606, TOI-1227, UCAC4 088-032065, WISE J122704.24-722706.5, WISEA J122704.22-722706.5}}

{{Starbox reference

|Simbad=TOI-1227

}}

{{Starbox end}}

TOI-1227 was first identified as a pre-main-sequence star (PMS star) with the Gaia satellite.{{Cite journal |last1=Goldman |first1=Bertrand |last2=Röser |first2=Siegfried |last3=Schilbach |first3=Elena |last4=Moór |first4=Attila C. |last5=Henning |first5=Thomas |date=2018-11-01 |title=A Large Moving Group within the Lower Centaurus Crux Association |journal=The Astrophysical Journal |volume=868 |issue=1 |pages=32 |doi=10.3847/1538-4357/aae64c |arxiv=1807.02076 |bibcode=2018ApJ...868...32G |s2cid=119343278 |issn=0004-637X |doi-access=free }}{{Cite journal |last1=Zari |first1=E. |last2=Hashemi |first2=H. |last3=Brown |first3=A. G. A. |last4=Jardine |first4=K. |last5=de Zeeuw |first5=P. T. |date=2018-12-01 |title=3D mapping of young stars in the solar neighbourhood with Gaia DR2 |url=https://ui.adsabs.harvard.edu/abs/2018A&A...620A.172Z |journal=Astronomy and Astrophysics |volume=620 |pages=A172 |doi=10.1051/0004-6361/201834150 |arxiv=1810.09819 |bibcode=2018A&A...620A.172Z |s2cid=119078481 |issn=0004-6361}}{{Cite journal |last1=Kerr |first1=Ronan M. P. |last2=Rizzuto |first2=Aaron C. |last3=Kraus |first3=Adam L. |last4=Offner |first4=Stella S. R. |date=2021-08-01 |title=Stars with Photometrically Young Gaia Luminosities Around the Solar System (SPYGLASS). I. Mapping Young Stellar Structures and Their Star Formation Histories |journal=The Astrophysical Journal |volume=917 |issue=1 |pages=23 |doi=10.3847/1538-4357/ac0251 |arxiv=2105.09338 |bibcode=2021ApJ...917...23K |s2cid=234790391 |issn=0004-637X |doi-access=free }} 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 {{convert|101|pc|ly|lk=on|abbr=off}}. NGC 4372 is {{convert|5800|pc|ly}} away.{{Cite journal |last=Boyles |first=Jason |last2=Lorimer |first2=Duncan R. |last3=Turk |first3=Phil J. |last4=Mnatsakanov |first4=Robert |last5=Lynch |first5=Ryan S. |last6=Ransom |first6=Scott M. |last7=Freire |first7=Paulo C. |last8=Belczynski |first8=Khris |date=2011-11-20 |title=Young Radio Pulsars in Galactic Globular Clusters |url=http://arxiv.org/abs/1108.4402 |journal=The Astrophysical Journal |volume=742 |issue=1 |pages=51 |doi=10.1088/0004-637X/742/1/51 |issn=0004-637X|arxiv=1108.4402 }}

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 {{RA|12|27|4.31}} and the declination {{DEC|-72|27|6.5}} implies that it is located in the Musca constellation.{{Cite web |title=TOI-1227|url=https://simbad.cds.unistra.fr/mobile/object.html?object_name=TOI-1227 |access-date=2024-02-14 |website=simbad.cds.unistra.fr}}{{Efn|The constellation can be obtained by the right ascension and declination in this [https://djm.cc/constellation.html website].}} The host star shows Lithium in its atmosphere, which should be depleted within 10-200 million years for M-dwarfs.

{{reflist}}

{{2022 in space}}

1227

Category:Transiting exoplanets

Category:Exoplanets discovered in 2022

Category:Protoplanets