Effective temperatures of detached eclipsing binaries computed through Hipparcos trigonometric parallaxes are compared with the photometric determinations. The former are based on the values of the radius, the apparent visual magnitude and the bolometric correction of the star, whereas the latter are obtained from standard calibrations using Strömgren or Johnson colour indices. The working samp...

Although Ethiopia is endowed with diverse agro-ecologies suitable for cereal production, the success of production relies more on climate condition. Therefore, this study initiated to analyze trends of; crops area and productivity in Ethiopia. Data meher season (qt/ha) (ha) were collected from Central statistical Agency (CSA) Trend test was carried out using non-parametric Mann-Kendall’s ...

ABSTRACT We present the results of a study aiming at retrieving fundamental parameters M dwarfs from spectra secured with SPIRou, near-infrared high-resolution spectropolarimeter installed Canada–France–Hawaii Telescope (CFHT), in framework SPIRou Legacy Survey (SLS). Our relies on comparing observed two grids synthetic spectra, respectively, computed PHOENIX and MARCS model atmospheres, ultima...

Ethiopia is one of the major producers maize and wheat only producer teff at a larger scale for grain in sub-Saharan Africa (SSA). Various efforts have been made by government to increase productivity over past 15 years. Here we analyze dataset with more than 1,260 yield observations from 2004/05 2018/19 three crops (teff, maize, wheat) 28 zones two cereal-growing regions country. These regions...

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are “cool” (Teff < 6000 K) rather than “warm” (Teff > 6000 K) suggests that the prepon...

Localization of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells to lymphoid and non-lymphoid tissue is instrumental for the effective control of immune responses. Compared with conventional T cells, Treg cells constitute a minute fraction of the T-cell repertoire. Despite this numeric disadvantage, Tregs efficiently migrate to sites of immune responses reaching an optimal number for the regulat...

We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS 1039+4112 (B = 15.9) and HE 1429−0343 (B = 15.8) from time-series photometry made at the Loiano 1.5 m telescope. The two stars were previously selected as probable pulsators based on two-color photometry and spectral analysis respectively. Following our temperature and surface gravity determinations, HS 1039+4112...

Spectral analysis needs the observation of lines of successive ionization stages in order to evaluate the ionization equilibrium (of a particular species) which is a sensitive indicator for the effective temperature (Teff). Since stars with Teff as high as 100 000K have their flux maximum in the extreme ultraviolet (EUV) wavelength range and due to the high degree of ionization, most of the met...

The results of a search for cool subdwarfs are presented. Kinematic (U, V, and W) and stellar parameters (Teff , log g, [Fe/H], and ξt) are derived for 134 candidate subdwarfs based on high resolution spectra. The observed stars span 4200K < Teff < 6400K and −2.70 < [Fe/H] < 0.25 including only 8 giants (log g < 4.0). Of the sample, 100 stars have MgH bands present in their spectra. The targets...

In this work we present the results of our analysis 16,300 medium-resolution LAMOST spectra late-type stars in Kepler field with aim determining stellar parameters, activity level, lithium atmospheric content, and binarity. We have used a version code ROTFIT specifically developed for these spectra. provide catalog parameters (Teff, log(g), [Fe/H]), radial velocity (RV), projected rotation (vsi...