An ultrahot Neptune in the Neptune desert

About one out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014; Winn et al. 2018). All of the previously known ultra-short-period planets are either hot Jupiters, with sizes above 10 Earth radii (Re), or apparently rocky planets smaller than 2 Re. Such lack of planets of intermediate size (the "hot Neptune desert") has been interpreted as the inability of low-mass planets to retain any hydrogen/helium (H/He) envelope in the face of strong stellar irradiation. Here, we report the discovery of an ultra-short-period planet with a radius of 4.6 Re and a mass of 29 Me, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite (Ricker et al. 2015) revealed transits of the bright Sun-like star \starname\, every 0.79 days. The planet's mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/He-rich envelope constituting 9.0^(+2.7)_(-2.9)% of the total mass. With an equilibrium temperature around 2000 K, it is unclear how this "ultra-hot Neptune" managed to retain such an envelope. Follow-up observations of the planet's atmosphere to better understand its origin and physical nature will be facilitated by the star's brightness (Vmag=9.8)

PTFO 8-8695: Two Stars, Two Signals, No Planet

© 2020. The American Astronomical Society. All rights reserved.. PTFO 8-8695 (CVSO 30) is a star in the 7-10 million year old Orion OB1a cluster that shows brightness dips that resemble planetary transits. Although strong evidence against the planet hypothesis has been presented, the possibility remains debated in the literature. To obtain further clues, we inspected data from the NASA Transiting Exoplanet Survey Satellite (TESS) and the ESA Gaia mission. The Gaia data suggest that PTFO 8-8695 is a binary: the photometric data show it to be overluminous with respect to members of its kinematic group, and the astrometric data are inconsistent with a single star. The TESS light curve shows two different photometric periods. The variability is dominated by a sinusoidal signal with a period of 11.98 hr, presumably caused by stellar rotation. Also present is a 10.76 hr signal consisting of a not-quite sinusoid interrupted by hour-long dips, the type of signal previously interpreted as planetary transits. The phase of the dips is nearly 180 away from the phase of the originally reported dips. As noted previously, this makes them difficult to explain as planetary transits. Instead, we believe that PTFO 8-8695 is a pair of young and rapidly rotating M dwarfs, one of which shows the same "transient-dipper"behavior that has been seen in at least five other cases. The origin of these transient dips is still unknown but likely involves circumstellar material

Geriatric Oncology

The decrease in muscle mass and strength represents one of the most relevant descriptor of physiological aging. Sarcopenia is the term coined to indicate the pathologic loss of skeletal muscle mass and strength/function during aging. The skeletal muscle decline has a multifactorial origin, involving lifestyle habits, disease triggers, and age-dependent biological changes. This phenomenon is part of the geriatric background and is today starting to disseminate in other specialties dealing with the complexity of frail older persons. In the oncology field, the interest in muscle wasting has mostly been focused on the clinical entity of cancer cachexia, a complex metabolic syndrome characterized by severe muscle loss, systemic inflammation, and malnutrition. The study of body composition in the oncological setting is crucial and may become one of the main characterizations of the oncogeriatric field, where clinical and research actions have to be designed taking into account the consequences of the aging process