Abstract
The microlensing event OGLE-2017-BLG-1434 features a cold super-Earth planet that is 1 of 11 microlensing planets with a planet–host-star mass ratio of
q
< 1 × 10
−4
. We provide an ...additional mass–distance constraint on the lens host using near-infrared adaptive optics photometry from Keck/NIRC2. We are able to determine a flux excess of
K
L
= 16.96 ± 0.11, which most likely comes entirely from the lens star. Combining this with constraints from the large Einstein ring radius,
θ
E
= 1.40 ± 0.09 mas, and OGLE parallax we confirm this event as a super-Earth with a mass of
m
p
= 4.43 ± 0.25
M
⊕
. This system lies at a distance of
D
L
= 0.86 ± 0.05 kpc from Earth and the lens star has a mass of
M
L
= 0.234 ± 0.012
M
⊙
. We confirm that with a star–planet mass ratio of
q
= 0.57 × 10
−4
, OGLE-2017-BLG-1434 lies near the inflexion point of the planet–host mass-ratio power law.
The high-magnification microlensing event MACHO-97-BLG-28 was previously determined to be a binary system composed of either two M dwarfs or an M dwarf and a brown dwarf. We present a revised ...light-curve model using additional data from the Mt. Stromlo 74″ telescope, model estimates of stellar limb darkening, and fitting of the blend separately for each telescope and passband. We find a lensing system with a larger mass ratio, q = 0.28 0.01, and smaller projected separation, s = 0.61 0.01, than those presented in the original study. We revise the estimate of the lens-source relative proper motion to rel = 2.8 0.5 mas yr−1, which indicates that 16.07 yr after the event maximum the lens and source should have separated by 46 8 mas. We revise the radius of the source star using more recent reddening maps and angular diameter-color relations to R* = (10.3 1.9) R . K- and J-band adaptive optics images of the field taken at this epoch using the NIRC2 imager on the Keck telescope show that the source and lens are still blended, consistent with our light-curve model. With no statistically significant excess flux detection we constrain the mass, , and distance, DL = 7.0 1.0 kpc, of the lensing system. This supports the interpretation of this event as a stellar binary in the Galactic bulge. This lens mass gives a companion mass of , close to the boundary between being a star and a brown dwarf.
ABSTRACT
We present K2-2016-BLG-0005Lb, a densely sampled, planetary binary caustic-crossing microlensing event found from a blind search of data gathered from Campaign 9 of the Kepler K2 mission ...(K2C9). K2-2016-BLG-0005Lb is the first bound microlensing exoplanet discovered from space-based data. The event has caustic entry and exit points that are resolved in the K2C9 data, enabling the lens-source relative proper motion to be measured. We have fitted a binary microlens model to the Kepler data and to simultaneous observations from multiple ground-based surveys. Whilst the ground-based data only sparsely sample the binary caustic, they provide a clear detection of parallax that allows us to break completely the microlensing mass-position-velocity degeneracy and measure the planet’s mass directly. We find a host mass of 0.58 ± 0.04 M⊙ and a planetary mass of 1.1 ± 0.1 MJ. The system lies at a distance of 5.2 ± 0.2 kpc from Earth towards the Galactic bulge, more than twice the distance of the previous most distant planet found by Kepler. The sky-projected separation of the planet from its host is found to be 4.2 ± 0.3 au which, for circular orbits, deprojects to a host separation $a = 4.4^{+1.9}_{-0.4}$ au and orbital period $P = 13^{+9}_{-2}$ yr. This makes K2-2016-BLG-0005Lb a close Jupiter analogue orbiting a low-mass host star. According to current planet formation models, this system is very close to the host mass threshold below which Jupiters are not expected to form. Upcoming space-based exoplanet microlensing surveys by NASA’s Nancy Grace Roman Space Telescope and, possibly, ESA’s Euclid mission, will provide demanding tests of current planet formation models.
Objective: The aim of this work was to develop an index that evaluates the degree of adherence to existing dietary and lifestyle guidelines for primary school-aged children (Healthy Lifestyle–Diet ...Index (HLD-Index)) and examine its relationship with selected nutrient intake and insulin resistance (IR). Methods: Ten components were used to develop the HLD-Index. Scores from 0 to 4 were assigned to all components. The HLD-Index total score ranged between 0 and 40. A sample of 729 schoolchildren from Greece aged 10–12 years (The Healthy Growth Study) was used to evaluate the validation of the proposed index. Results: The overall mean±standard deviation of the HLD-Index score was 20±4.4. Higher HLD-Index scores were associated with lower proportion of children having intakes lower than Estimated Average Requirements by Institute of Medicine. On the basis of the cutoff point of 3.16 for homeostasis model assessment of IR, 20.9% of participants were found to be insulin resistant. After adjusting for potential confounders, logistic regression showed that a 1 unit increase in the score is associated with almost 8% lower odds for being insulin resistant. The cutoff point analysis revealed that score equal to or lower than 21 best discriminates children with IR from those without IR. On the basis of this cutoff point, the sensitivity of the HLD-Index was 70% and the corresponding specificity was 47%. Conclusions: The proposed HLD-Index could be used by public health policy makers and other health-care professionals to identify subgroups in the population with poor diet–lifestyle habits who are at increased probability for IR.
Context.
Brown dwarfs are transition objects between stars and planets that are still poorly understood, for which several competing mechanisms have been proposed to describe their formation. Mass ...measurements are generally difficult to carry out for isolated objects as well as for brown dwarfs orbiting low-mass stars, which are often too faint for a spectroscopic follow-up.
Aims.
Microlensing provides an alternative tool for the discovery and investigation of such faint systems. Here, we present an analysis of the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035, which is caused by a binary system composed of a brown dwarf orbiting a red dwarf.
Methods.
Thanks to extensive ground observations and the availability of space observations from
Spitzer,
it has been possible to obtain accurate estimates of all microlensing parameters, including the parallax, source radius, and orbital motion of the binary lens.
Results.
Following an accurate modeling process, we found that the lens is composed of a red dwarf with a mass of
M
1
= 0.149 ± 0.010
M
⊙
and a brown dwarf with a mass of
M
2
= 0.0463 ± 0.0031
M
⊙
at a projected separation of
a
⊥
= 0.585 au. The system has a peculiar velocity that is typical of old metal-poor populations in the thick disk. A percent-level precision in the mass measurement of brown dwarfs has been achieved only in a few microlensing events up to now, but will likely become more common in the future thanks to the
Roman
space telescope.
Abstract Background Second to fourth digit ratio (2D:4D) is associated with cardiometabolic risk in adults. Aim To examine the association of right 2D:4D with cardiovascular disease risk factors in ...children. Study design Cross-sectional study. Subjects A sample of 301 children (53.5% girls) aged 9–13 in Greece and their parents. Children who were sick during the previous week of examination (n = 44) were excluded from the analyses. Outcome measures Socio-demographic (gestational age, birth weight, age, gender, maternal education level), anthropometric (body weight and height, finger length), clinical (pubertal stage, sickness during the previous week of the examination), blood serum high sensitivity C-reactive protein (CRP), serum high sensitivity interleukin-6 (IL-6), serum leptin, lifestyle (dietary intake, maternal smoking during pregnancy) and physical fitness (handgrip strength) data were collected. CRP, IL-6 and leptin were measured with ELISA, using standard equipment and procedures, in accordance with manufacturers' instructions. Results Full data were available for 257 children (52.1% girls). The rank values of right 2D:4D and IL-6 were included in the analyses. Right 2D:4D was correlated only with IL-6 at a bivariate level (r = 0.216, p = 0.012) in girls. At a linear multivariate level, this association remained significant, even after adjusting for several potential confounders such as age, Tanner stage, maternal education level, body mass index, maternal smoking during pregnancy, duration of pregnancy, protein-, carbohydrate-, fat-intake and physical fitness (β ± SE = 0.220 ± 0.066, p = 0.001). Conclusions Right 2D:4D was found to be associated with IL-6 in girls. Right 2D:4D may be a valuable, simple screening tool of low-grade inflammation in children.
The microlensing event OGLE-2017-BLG-1434 features a cold super-Earth planet which is one of eleven microlensing planets with a planet-host star mass ratio \(q < 1 \times 10^{-4}\). We provide an ...additional mass-distance constraint on the lens host using near-infrared adaptive optics photometry from Keck/NIRC2. We are able to determine a flux excess of \(K_L = 16.96 \pm 0.11\) which most likely comes entirely from the lens star. Combining this with constraints from the large Einstein ring radius, \(\theta_E=1.40 \pm 0.09\;mas\) and OGLE parallax we confirm this event as a super-Earth with mass \(m_p = 4.43 \pm 0.25M_\odot\). This system lies at a distance of \(D_L = 0.86 \pm 0.05\,kpc\) from Earth and the lens star has a mass of \(M_L=0.234\pm0.012M_\odot\). We confirm that with a star-planet mass ratio of \(q=0.57 \times 10^{-4}\), OGLE-2017-BLG-1434 lies near the inflexion point of the planet-host mass-ratio power law.
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