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Context: Starspots are important manifestations of stellar magnetic activity. By studying their behaviour in young solar analogues, we can unravel the properties of their magnetic cycles. This gives crucial information of the underlying dynamo process. Comparisons with the solar cycle enable us to infer knowledge about how the solar dynamo has evolved during the Sun's lifetime. Aims: Here we study the correlation between photometric brightness variations, spottedness, and mean temperature in V889 Her, a young solar analogue. Our data covers 18 years of spectroscopic and 25 years of photometric observations. Methods: We use Doppler imaging to derive temperature maps from high-resolution spectra. We use the Continuous Period Search method to retrieve mean V-magnitudes from photometric data. Results: Our Doppler imaging maps show a persistent polar spot structure varying in strength. This structure is centred slightly off the rotational pole. The mean temperature derived from the maps shows an overall decreasing trend, as does the photometric mean brightness, until it reaches its minimum around 2017. The filling factor of cool spots, however, shows only a weak tendency to anti-correlate with the decreasing mean brightness. Conclusions: We interpret V889 Her to have entered into a grand maximum in its activity. The clear relation between the mean temperature of the Doppler imaging surface maps and the mean magnitude supports the reliability of the Doppler images. The lack of correlation between the mean magnitude and the spottedness may indicate that bright features in the Doppler images are real.

Актуальність. Актуальність вивчення проблеми оогенезу обумовлена високою частотою безплідних шлюбів, пов'язаних з проблемами в репродуктивній сфері. Ооцити людини на стадії метафази ІІ мейозу характеризуються вираженим поліморфізмом першого полярного тіла, морфологічні особливості якого можуть бути предиктором хромосомного статусу розвинутих ембріонів. Мета. Визначення хромосомного статусу ембріонів, отриманих із ооцитів з різними характеристиками першого полярного тіла. Методи. Передімплантаційно-генетичний аналіз ембріонів проводили за допомогою молекулярно-цитогенетичних методів; культуральні методи використовували для запліднення ооцитів та розвитку ембріонів передімплантаційних стадій розвитку, оцінку ооцитів та розвитку ембріонів здійснювали з використанням світлової та флуоресцентної мікроскопії, також застосовували кріобіологічні та методи статистичної обробки результатів. Результати. Було показано, що частота запліднення ооцитів не залежить від морфологічних характеристик першого полярного тіла. Проте ооцити із збільшеним та розсіяно-фрагментованим полярним тілом після запліднення не розвиваються до стадії бластоцисти, що унеможливлює проведення їх генетичного аналізу. Запліднення ооцитів з локальною фрагментацією полярного тіла не призводить до збільшення частоти анеуплоїдій у хромосомному наборі ембріонів. Підсумок. Морфологічні характеристики першого полярного тіла можуть опосередковано свідчити про хромосомний статус ембріонів людини. Отримані дані дозволять полегшити відбір яйцеклітин для пацієнтів, які проходять лікування методами ДРТ у випадках, коли слід уникати створення надмірної кількості ембріонів., Background. The relevance of studying problem of oogenesis is due to the high rate of infertile marriages associated with problems in the reproductive sphere. Human oocytes at meiosis metaphase II are characterized by polymorphism of the first polar body, which morphological features can be a predictor of the embryos chromosomal status. Objective. Determination of chromosomal status of embryos derived from oocytes with different morphological characteristics of the first polar body. Methods. Preimplantation-genetic analysis of embryos was performed using molecular cytogenetic methods; culturing method was used to fertilised oocyte and development of preimplantation embryo, assessment of oocyte and embryo development were studied by the light and fluorescence microscopy; cryobiological and statistical methods were also used. Results. It has been shown that the oocyte fertilization rate does not dependent on the first polar body morphology. However, oocytes with an enlarged and scattered-fragmented polar body do not develop after fertilization until blastocyst stage. That is why it impossible to carry out their genetic analysis. Ferltilisation of the oocytes with local fragmentation of the polar body does not increase the incidence of embryo aneuploidy. Conclusion. The morphological characteristics of the first polar body may indirectly indicate the chromosomal status of human embryos. The data obtained will facilitate the selection of eggs for patients undergoing ART treatment in cases where the creation of an excessive number of embryos should be avoided., Актуальность. Актуальность изучения проблемы оогенеза обусловлена высокой частотой бесплодных браков, связанных с проблемами в репродуктивной сфере. Ооциты человека на стадии метафаза ІІ мейоза характеризуются выраженным полиморфизмом первого полярного тела, морфологические особенности которого могут быть предиктором хромосомного статуса полученных эмбрионов. Цель. Определение хромосомного статуса эмбрионов, полученных из ооцитов с различными характеристиками первого полярного тела. Методы. Доимплантационно-генетический анализ эмбрионов проводили с помощью молекулярно-цитогенетических методов; культуральные методы использовали для оплодотворения ооцитов и развития ембрионов доимплантационных стадий развития, оценка ооцитов и развития ембрионов осуществляли с использованием световой и флуоресцентной микроскопией, также применяли криобиологические и методы статистической обработки результатов. Результаты. Было показано, что частота оплодотворения ооцитов не зависит от морфологических характеристик первого полярного тела. Однако ооциты с увеличенным и рассеянно-фрагментированным полярным телом после оплодотворения не развиваются до стадии бластоцисты, что делает невозможным проведение их генетического анализа. Оплодотворения ооцитов с локальной фрагментации полярного тела частота не приводит к увеличению возникновения анеуплоидий в хромосомном наборе эмбрионов. Выводы. Морфологические характеристики первого полярного тела могут косвенно свидетельствовать о хромосомный статус эмбрионов человека. Полученные данные позволят облегчить отбор яйцеклеток для пациентов, проходящих лечение методами ВРТ в случаях, когда следует избегать создания чрезмерного количества эмбрионов.

As part of the first Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) key-science project, we aim to provide well-exposed (viz. deep) high-resolution spectra of representative stellar targets. These spectra will be made available in form of (electronic) atlases. The first star in this series of papers is our Sun. It also acts as a system-performance cornerstone. The deep spectra in this paper are the results of combining up to 100 consecutive exposures per wavelength setting and are compared with other solar flux atlases. Our software for the optimal data extraction and reduction of PEPSI spectra is described and verified with the solar data. Three deep solar flux spectra with a spectral resolution of up to 270,000, a continuous wavelength coverage from 383 nm to 914 nm, and a photon signal to noise ratio (S/N) of between 2,000-8,000:1 depending on wavelength are presented. Additionally, a time-series of 996 high-cadence spectra in one cross disperser is used to search for intrinsic solar modulations. The wavelength calibration based on Th-Ar exposures and simultaneous Fabry-Perot combs enables an absolute wavelength solution within 10 m/s (rms) with respect to the HARPS laser-comb solar atlas and a relative rms of 1.2 m/s for one day. For science demonstration, we redetermined the disk-average solar Li abundance to 1.09+/-0.04 dex on the basis of 3D NLTE model atmospheres. We detected disk-averaged p-mode RV oscillations with a full amplitude of 47 cm/s at 5.5 min. Comparisons with two solar FTS atlases, as well as with the HARPS solar atlas, validate the PEPSI data product. Now, PEPSI/SDI solar-flux spectra are being taken with a sampling of one deep spectrum per day, and are supposed to continue a full magnetic cycle of the Sun., Comment: in press, 13 pages, 8 figures, data available from pepsi.aip.de

We obtained an LBT/PEPSI spectrum with very high resolution and high signal-to-noise ratio (S/N) of the K0V host Kepler-444, which is known to host 5 sub-Earth size rocky planets. The spectrum has a resolution of R=250,000, a continuous wavelength coverage from 4230 to 9120A, and S/N between 150 and 550:1 (blue to red). We performed a detailed chemical analysis to determine the photospheric abundances of 18 chemical elements, in order to use the abundances to place constraints on the bulk composition of the five rocky planets. Our spectral analysis employs the equivalent width method for most of our spectral lines, but we used spectral synthesis to fit a small number of lines that require special care. In both cases, we derived our abundances using the MOOG spectral analysis package and Kurucz model atmospheres. We find no correlation between elemental abundance and condensation temperature among the refractory elements. In addition, using our spectroscopic stellar parameters and isochrone fitting, we find an age of 10+/-1.5 Gyr, which is consistent with the asteroseismic age of 11+/-1 Gyr. Finally, from the photospheric abundances of Mg, Si, and Fe, we estimate that the typical Fe-core mass fraction for the rocky planets in the Kepler-444 system is approximately 24 per cent. If our estimate of the Fe-core mass fraction is confirmed by more detailed modeling of the disk chemistry and simulations of planet formation and evolution in the Kepler-444 system, then this would suggest that rocky planets in more metal-poor and alpha-enhanced systems may tend to be less dense than their counterparts of comparable size in more metal-rich systems., Comment: in press, 11 pages, 3 figures, data available from pepsi.aip.de

We provide a homogeneous library of high-resolution, high-S/N spectra for 48 bright AFGKM stars, some of them approaching the quality of solar-flux spectra. Our sample includes the northern Gaia benchmark stars, some solar analogs, and some other bright Morgan-Keenan (M-K) spectral standards. Well-exposed deep spectra were created by average-combining individual exposures. The data-reduction process relies on adaptive selection of parameters by using statistical inference and robust estimators.We employed spectrum synthesis techniques and statistics tools in order to characterize the spectra and give a first quick look at some of the science cases possible. With an average spectral resolution of R=220,000 (1.36 km/s), a continuous wavelength coverage from 383 nm to 912 nm, and S/N of between 70:1 for the faintest star in the extreme blue and 6,000:1 for the brightest star in the red, these spectra are now made public for further data mining and analysis. Preliminary results include new stellar parameters for 70 Vir and alpha Tau, the detection of the rare-earth element dysprosium and the heavy elements uranium, thorium and neodymium in several RGB stars, and the use of the 12C to 13C isotope ratio for age-related determinations. We also found Arcturus to exhibit few-percent CaII H&K and H-alpha residual profile changes with respect to the KPNO atlas taken in 1999., Comment: in press, 15 pages, 7 figures, data available from pepsi.aip.de

The magnetic field of CPD -57 3509 was recently detected in the framework of the BOB (B fields in OB stars) collaboration. We acquired low-resolution spectropolarimetric observations of CPD -57 3509 with FORS2 and high-resolution UVES observations randomly distributed over a few months to search for periodicity, to study the magnetic field geometry, and to determine the surface distribution of silicon and helium. We also obtained supplementary photometric observations at a timeline similar to the spectroscopic and spectropolarimetric observations. A period of 6.36d was detected in the measurements of the mean longitudinal magnetic field. A sinusoidal fit to our measurements allowed us to constrain the magnetic field geometry and estimate the dipole strength in the range of 3.9-4.5kG. Our application of the Doppler imaging technique revealed the presence of He I spots located around the magnetic poles, with a strong concentration at the positive pole and a weaker one around the negative pole. In contrast, high concentration Si III spots are located close to the magnetic equator. Further, our analysis of the spectral variability of CPD -57 3509 on short time scales indicates distinct changes in shape and position of line profiles possibly caused by the presence of beta Cep-like pulsations. A small periodic variability in line with the changes of the magnetic field strength is clearly seen in the photometric data., Comment: 11 pages, 5 tables, 7 figures, accepted for publication in MNRAS

Context: HD 54879 (O9.7 V) is one of a dozen O-stars for which an organized atmospheric magnetic field has been detected. To gain insights into the interplay between atmospheres, winds, and magnetic fields of massive stars, we acquired UV and X-ray data of HD 54879 using the Hubble Space Telescope and the XMM-Newton satellite. In addition, 35 optical amateur spectra were secured to study the variability of HD 54879. A multiwavelength (X-ray to optical) spectral analysis is performed using the Potsdam Wolf-Rayet (PoWR) model atmosphere code and the xspec software. Results: The photospheric parameters are typical for an O9.7 V star. The microturbulent, macroturbulent, and projected rotational velocities are lower than previously suggested (<4 km/s). An initial mass of 16$\,M_\odot$ and an age of 5 Myr are inferred from evolutionary tracks. We derive a mean X-ray emitting temperature of $\log T_{\rm X} = 6.7\,$[K] and an X-ray luminosity of $\log L_\text{X} = 32\,$[erg/s]. Short- and long-scale variability is seen in the H-alpha line, but only a very long period of $P \approx 5\,$yr could be estimated. Assessing the circumstellar density of HD 54879 using UV spectra, we can roughly estimate the mass-loss rate HD 54879 would have in the absence of a magnetic field as $\log \dot{M}_{B=0}\approx -9.0\,[{M_\odot}/{\rm yr}]$. The magnetic field traps the stellar wind up to the Alfv\'en radius > $12\,R_\odot$, implying that its true mass-loss rate is $\log \dot{M}< -10.2\,[{M_\odot}/{\rm yr}]$. Hence, density enhancements around magnetic stars can be exploited to estimate mass-loss rates of non-magnetic stars of similar spectral types, essential for resolving the weak wind problem. Conclusions: Our study confirms that strongly magnetized stars lose little or no mass, and supplies important constraints on the weak-wind problem of massive main sequence stars., Comment: Accepted for publication in A&A on Aug. 9, 2017, 12 + 1 pages, 15 figures. Paper replaced due to typos and missing acknowledgments

Although pulsations of $\delta$ Scuti type are not expected among Ap stars from a theoretical point of view, previous observations of the known $\delta$ Scuti star HD21190 indicated a spectral classification F2 III SrEuSi:, making it the most evolved Ap star known. Our atmospheric chemical analysis based on recent HARPS observations confirms the presence of chemical peculiarities in HD21190. This star is also the only target known to host a magnetic field along with its $\delta$ Scuti pulsation properties. Using an astrometric analysis, we show that HD21190 forms a physical binary system with the companion CPD -83$^{\circ}$ 64B. The presented astrometric and spectroscopic study of the binary components is important to understand the complex interplay between stellar pulsations, magnetic fields, and chemical composition., Comment: 16 pages, 9 figures, 4 tables

HD 164492C is a spectroscopic triple stellar system that has been recently detected to possess a strong magnetic field. We have obtained high-resolution spectroscopic and spectropolarimetric observations over a timespan of two years and derived physical, chemical, and magnetic properties for this object. The system is formed by an eccentric close spectroscopic binary (Ca1-Ca2) with a period of 12.5 days, and a massive tertiary Cb. We calculated the orbital parameters of the close pair, reconstructed the spectra of the three components, and determined atmospheric parameters and chemical abundances by spectral synthesis. From spectropolarimetric observations, multi-epoch measurements of the longitudinal magnetic fields were obtained. The magnetic field is strongly variable on timescales of a few days, with a most probable period in the range of 1.4-1.6 days. Star Cb with Teff~25000 K is the apparently fastest rotator and the most massive star of this triple system and has anomalous chemical abundances with a marked overabundance of helium, 0.35+/-0.04 by number. We identified this star as being responsible for the observed magnetic field, although the presence of magnetic fields in the components of the Ca pair cannot be excluded. Star Ca1 with a temperature of about 24000 K presents a normal chemical pattern, while the least massive star Ca2 is a mid-B type star (Teff~15000 K) with an overabundance of silicon. The obtained stellar parameters of the system components suggest a distance of 1.5 kpc and an age of 10-15 Myr., Comment: 15 pages, 5 tables, 12 figures, accepted for publication in MNRAS

RZ Psc is an isolated high-latitude post-T Tauri star that demonstrates a UX Ori-type photometric activity. The star shows very weak spectroscopic signatures of accretion, but at the same time possesses the unusual footprints of the wind in Na I D lines. In the present work we investigate new spectroscopic observations of RZ Psc obtained in 2014 during two observation runs. We found variable blueshifted absorption components (BACs) in lines of the other alcali metals, K I 7699 \AA\ and Ca II IR triplet. We also confirmed the presence of a weak emission component in the H$\alpha$ line, which allowed us to estimate the mass accretion rate on the star as $\dot{M}\leq$ $7 \cdot 10^{-12}$Msun yr$^{-1}$. We could not reveal any clear periodicity in the appearance of BACs in sodium lines. Nevertheless, the exact coincidence of the structure and velocities of the Na I D absorptions observed with the interval of about one year suggests that such a periodicity should exist.

A longitudinal magnetic field with a strength of 5.2kG was recently detected in CPD -62 2124, which has a fractional main-sequence lifetime of about 60%. Strongly magnetic early-B type chemically peculiar stars in an advanced evolutionary state are of special interest to understand the evolution of the angular momentum and spin-down timescales in the presence of a global magnetic field. We exploited 17 FORS2 low-resolution spectropolarimetric observations and 844 ASAS3 photometric measurements for the determination of the rotation period, pulsations, and the magnetic field geometry of the star. We calculated periodograms and applied phenomenological models of photometric, spectral and spectropolarimetric variability. We found that all quantities studied, specifically equivalent widths, the mean longitudinal magnetic field , and the flux in the V filter, vary with the same period P = 2.628d, which was identified as the rotation period. The observed variations can be fully explained by a rigidly rotating main-sequence star with an uneven distribution of chemical elements, photometric spots, and a stable, nearly dipolar magnetic field with a polar field strength of about 21kG, frozen into the body of the star. The magnetic field of CPD -62 2124 is tilted to the rotation axis by beta=28+-7deg, while the inclination of the rotation axis towards the line of sight is only i=20+-5deg. In the acquired FORS2 spectra, we detect short-term line profile variations indicating the presence of beta Cephei type pulsations. As of today, no other pulsating star of this type is known to possess such a strong magnetic field., Comment: 9 pages, 3 tables, 9 figures, accepted for publication in MNRAS

A team involved in APOGEE, one of the Sloan Digital Sky Survey III programs, recently announced the discovery of two rare rigidly rotating magnetosphere stars, HD345439 and HD23478. Near-infrared spectra of these objects revealed emission-line behavior identical to that previously discovered in the helium-strong star sigma Ori E, which has a strong magnetic field and rotates fast. A single spectropolarimetric observation of HD345439 with FORS2 at the VLT in 2014 over 88min indicated that HD345439 may host a strong, rapidly varying magnetic field. In this work, we present the results of our spectropolarimetric monitoring of this star with FORS2, which revealed the presence of a strong longitudinal magnetic field dominated by a dipolar component. The analysis of spectral variability indicates an opposite behaviour of He and Si lines, which is usually attributed to differences in the distribution of surface He and Si abundance spots., Comment: 5 pages, 1 table, 6 figures, accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1702.01063