Four new HgMn stars: HD 18104, HD 30085, HD 32867, HD 53588

We have detected four new HgMn stars, while monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere. Important classification lines of Hg II and Mn II are found as conspicuous features in the high resolution SOPHIE spectra of these stars (R = 75000). Several lines of Hg II, Mn II and Fe II have been synthesized using model atmospheres and the spectrum synthesis code SYNSPEC48 including hyperfine structure of various isotopes when relevant. These synthetic spectra have been compared to high resolution high signal-to-noise observations of these stars in order to derive abundances of these key elements. The four stars are found to have distinct enhancements of Hg and Mn which show that these stars are not superficially normal B and A stars, but actually are new HgMn stars and should reclassified as such.Comment: 4 pages, 3 figures, accepted in A&

Generating stellar spectra using Neural Networks

A new generative technique is presented in this paper that uses Deep Learning to reconstruct stellar spectra based on a set of stellar parameters. Two different Neural Networks were trained allowing the generation of new spectra. First, an autoencoder is trained on a set of BAFGK synthetic data calculated using ATLAS9 model atmospheres and SYNSPEC radiative transfer code. These spectra are calculated in the wavelength range of Gaia RVS between 8 400 and 8 800 {\AA}. Second, we trained a Fully Dense Neural Network to relate the stellar parameters to the Latent Space of the autoencoder. Finally, we linked the Fully Dense Neural Network to the decoder part of the autoencoder and we built a model that uses as input any combination of $T_{eff}$, $\log g$, $v_e \sin i$, [M/H], and $\xi_t$ and output a normalized spectrum. The generated spectra are shown to represent all the line profiles and flux values as the ones calculated using the classical radiative transfer code. The accuracy of our technique is tested using a stellar parameter determination procedure and the results show that the generated spectra have the same characteristics as the synthetic ones.Comment: 13 pages, 9 figures, accepted in Astronomy (MDPI

Principal component analysis-based inversion of effective temperatures for late-type stars

We show how the range of application of the principal component analysis-based inversion method of Paletou et al. (2015) can be extended to late-type stars data. Besides being an extension of its original application domain, for FGK stars, we also used synthetic spectra for our learning database. We discuss our results on effective temperatures against previous evaluations made available from Vizier and Simbad services at CDS.Comment: Accepted for publication in A&

Marriage Responsibilities

"Orthodox Christianity is a way of life that is a whole coming together of habits and attitudes, ideas and actions : a lifestyle. Many Orthodox Christians do not live in monasteries: they are married; they have homes, children, and jobs. But all Christians, whether monastic or not, are equally called by Christ to repentance and eternal salvation. There are no classes of Orthodox Christians; all are equal and all are expected to be followers of Christ, regardless of their position in the church. However, it is very difficult for Christians to live an Orthodox lifestyle. ‘Behold, I send you out as sheep in the midst of wolves; be wise as serpents and innocent as doves.’ (Matt 10:16) Marriage and family life are a tremendous bastion of strength for Orthodox lay people, a state that has been blessed by God for the salvation of each individual member of the family. In order to fully understand this, we must look at the doctrinal foundations of marriage found in the Scripture (God’s Holy Word) and the Sacred Tradition (the wisdom of the church through the ages).", pp. 71-72 (Introduction