We report the discovery by the TESS mission of a super-Earth on a 4.8-d orbit around an inactive M4.5 dwarf (TOI-1680) validated by ground-based facilities. The host star is located 37.14 pc away, ...with a radius of 0.2100+/-0.0064 R_sun, mass of 0.1800+/-0.0044 M_sun and an effective temperature of 3211+/-100 K. We validated and characterized the planet using TESS data, ground-based multi-wavelength photometry from TRAPPIST, SPECULOOS, and LCO, as well as high-resolution AO observations from Keck/NIRC2 and Shane. Our analyses have determined the following parameters for the planet: a radius of 1.466+0.063/-0.049 R_earth and an equilibrium temperature of 404+/-14 K, assuming no albedo and perfect heat redistribution. Assuming a mass based on mass-radius relations, this planet is a promising target for atmospheric characterization with the James Webb Space Telescope (JWST).
We present the discovery from the TESS mission of two giant planets transiting M dwarf stars: TOI 4201 b and TOI 5344 b. We also provide precise radial velocity measurements and updated system ...parameters for three other M dwarfs with transiting giant planets: TOI 519, TOI 3629 and TOI 3714. We measure planetary masses of 0.525 +- 0.064 M_J, 0.243 +- 0.020 M_J, 0.689 +- 0.030 M_J, 2.57 +- 0.15 M_J, and 0.412 +- 0.040 M_J for TOI 519 b, TOI 3629 b, TOI 3714 b, TOI 4201 b, and TOI 5344 b, respectively. The corresponding stellar masses are 0.372 +- 0.018 M_s, 0.635 +- 0.032 M_s, 0.522 +- 0.028 M_s, 0.625 +- 0.033 M_s and 0.612 +- 0.034 M_s. All five hosts have super-solar metallicities, providing further support for recent findings that, like for solar-type stars, close-in giant planets are preferentially found around metal-rich M dwarf host stars. Finally, we describe a procedure for accounting for systematic errors in stellar evolution models when those models are included directly in fitting a transiting planet system.
We report the discovery and validation of two TESS exoplanets orbiting faint M dwarfs: TOI-4479b and TOI-2081b. We have jointly analyzed space (TESS mission) and ground based (MuSCAT2, MuSCAT3 and ...SINISTRO instruments) lightcurves using our multi-color photometry transit analysis pipeline. This allowed us to compute contamination limits for both candidates and validate them as planet-sized companions. We found TOI-4479b to be a sub-Neptune-sized planet (\(R_{p}=2.82^{+0.65}_{-0.63}~\rm R_{\oplus}\)) and TOI-2081b to be a super-Earth-sized planet (\(R_{p}=2.04^{+0.50}_{-0.54}~\rm R_{\oplus}\)). Furthermore, we obtained that TOI-4479b, with a short orbital period of \(1.15890^{+0.00002}_{-0.00001}~\rm days\), lies within the Neptune desert and is in fact the largest nearly ultra-short period planet around an M dwarf known to date. These results make TOI-4479b rare among the currently known exoplanet population around M dwarf stars, and an especially interesting target for spectroscopic follow-up and future studies of planet formation and evolution.
We report the discovery and confirmation of the planetary system TOI-1288. This late G dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne and ground-based transit ...photometry with HARPS-N and HIRES high-precision Doppler measurements, which we use to constrain the masses of both planets in the system and the radius of planet b. TOI-1288~b has a period of \(2.699835^{+0.000004}_{-0.000003}\) d, a radius of \(5.24 \pm 0.09\) R\(_\oplus\), and a mass of \(42 \pm 3\) M\(_\oplus\), making this planet a hot transiting super-Neptune situated right in the Neptunian desert. This desert refers to a paucity of Neptune-sized planets on short period orbits. Our 2.4-year-long Doppler monitoring of TOI-1288 revealed the presence of a Saturn-mass planet on a moderately eccentric orbit (\(0.13^{+0.07}_{-0.09}\)) with a minimum mass of \(84 \pm 7\) M\(_\oplus\) and a period of \(443^{+11}_{-13}\) d. The 5 sectors worth of TESS data do not cover our expected mid-transit time for TOI-1288 c, and we do not detect a transit for this planet in these sectors.
The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their ...picture. In this paper we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. We use a set of precise radial velocity observations from HARPS, PFS and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. We find that TOI-969 b is a transiting close-in (\(P_b\sim 1.82\) days) mini-Neptune planet (\(m_b=9.1^{+1.1}_{-1.0}\) M\(_{\oplus}\), \(R_b=2.765^{+0.088}_{-0.097}\) R\(_{\oplus}\)), thus placing it on the {lower boundary} of the hot-Neptune desert (\(T_{\rm eq,b}=941\pm31\) K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of \(P_c=1700^{+290}_{-280}\) days and a minimum mass of \(m_{c}\sin{i_c}=11.3^{+1.1}_{-0.9}\) M\(_{\rm Jup}\), and with a highly-eccentric orbit of \(e_c=0.628^{+0.043}_{-0.036}\). The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93, and it orbits a moderately bright (\(G=11.3\) mag) star, thus becoming an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems.
We analysed 68 candidate planetary systems first identified during Campaigns 5 and 6 (C5 and C6) of the NASA \textit{K2} mission. We set out to validate these systems by using a suite of follow-up ...observations, including adaptive optics, speckle imaging, and reconnaissance spectroscopy. The overlap between C5 with C16 and C18, and C6 with C17, yields lightcurves with long baselines that allow us to measure the transit ephemeris very precisely, revisit single transit candidates identified in earlier campaigns, and search for additional transiting planets with longer periods not detectable in previous works. Using \texttt{vespa}, we compute false positive probabilities of less than 1\% for 37 candidates orbiting 29 unique host stars and hence statistically validate them as planets. These planets have a typical size of \(2.2R_{\oplus}\) and orbital periods between 1.99 and 52.71 days. We highlight interesting systems including a sub-Neptune with the longest period detected by \textit{K2}, sub-Saturns around F stars, several multi-planetary systems in a variety of architectures. These results show that a wealth of planetary systems still remains in the \textit{K2} data, some of which can be validated using minimal follow-up observations and taking advantage of analyses presented in previous catalogs.
El objetivo del trabajo ha sido comparar las expresiónes del gen stearoyl-CoA desaturase (SCD), una enzima relacionada con la síntesis muscular en el ganado vacuno. La Marchigiana actual es una raza ...de vacuno que tiene un desarrollo somático elevado, con un alto nivel de crecimiento y de precocidad. Esta raza está difundida por las regiones de Marche, Lazio, Abruzzo y Campania con un total de 50000 cabezas inscritas en el libro genealógico. El gen myostatina es un factor de control negativo del crecimiento muscular. Si el gen está afectado por una mutación, produce una proteína no funcional y el consecuente crecimiento anormal del músculo en los animales criados. La mutación es una transversión de G a T en la posición 874 del tercer exón, llamada E291X. Se analizaron 3 animales normales y 6 con la mutación (3 heterozigotos y 3 homozigotos). Se le extrajo el ARN total de diferentes músculos (Semitendinosus, Psoas major and Longissimus thoracis lumborum) escogidos en diferentes zonas metabólicas (oxidativa, glicolítica e intermedia). El nivel de expresión del gen SCD se ha medido con el PCR en tiempo real, usando como patrón el gen 18S rARN. En los animales con la mutación, los resultados muestran que en todos los músculos estudiados la expresión es más baja (1,00 vs 1,76).
LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 parsecs. The primary star LTT 1445A (0.257 M_Sun) is known to host the transiting planet LTT 1445Ab with an orbital ...period of 5.4 days, making it the second closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using TESS data, we present the discovery of a second planet in the LTT 1445 system, with an orbital period of 3.1 days. We combine radial velocity measurements obtained from the five spectrographs ESPRESSO, HARPS, HIRES, MAROON-X, and PFS to establish that the new world also orbits LTT 1445A. We determine the mass and radius of LTT 1445Ab to be 2.87+/-0.25 M_Earth and 1.304^{+0.067}_{-0.060} R_Earth, consistent with an Earth-like composition. For the newly discovered LTT 1445Ac, we measure a mass of 1.54^{+0.20}_{-0.19} M_Earth and a minimum radius of 1.15 R_Earth, but we cannot determine the radius directly as the signal-to-noise of our light curve permits both grazing and non-grazing configurations. Using MEarth photometry and ground-based spectroscopy, we establish that star C (0.161 M_Sun) is likely the source of the 1.4-day rotation period, and star B (0.215 M_Sun) has a likely rotation period of 6.7 days. We estimate a probable rotation period of 85 days for LTT 1445A. Thus, this triple M-dwarf system appears to be in a special evolutionary stage where the most massive M dwarf has spun down, the intermediate mass M dwarf is in the process of spinning down, while the least massive stellar component has not yet begun to spin down.
We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611). This discovery is ...based on photometric measurements from the Transiting Exoplanet Survey Satellite(TESS) mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder (APF) and HIRES high precision spectrographs. We used EXOFASTv2 for simultaneously modeling the parameters of the planet and its host star, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50+/-0.08 RE and a mass of either 14.4+/-1.6 ME or 15.9+/-1.6 ME with nearly equal probability; the two solutions correspond to two possibilities for the stellar activity period. Hence, the density is either 5.1+/-0.7 g cm^-3 or 5.5^{+0.8}_{-0.7} g cm^-3, making it one of the relatively rare dense sub-Neptunes. The existence of such a dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2<RE<4) population. The most likely scenario is that this planet has migrated to its current position.
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