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We introduce a new solar feed for the PEPSI nighttime spectrograph of the LBT. It enables spectroscopy of the Sun‐as‐a‐star in circular polarization (CP) and linear polarization (LP) with a spectral resolution of 250,000 (≈0.025Å or 600ms−1$$ 600\kern0.1em \mathrm{m}\kern0.1em {\mathrm{s}}^{-1} $$) for the wavelength range 383–907 nm. The polarimeter is a dual‐beam design with a modified Wollaston prism as beam splitter and linear polarizer combined with a retractable super‐achromatic λ/4$$ \lambda /4 $$ retarder. The Wollaston beam diameter is 14 mm and large enough that it does not require a classical telescopic feed anymore. Both polarimetric beams are re‐imaged into respective integration spheres from which two fibers feed the scrambled light to the spectrograph. The system is fully automated in the sense that it finds the Sun in the morning, closes the guider loop, observes a predefined number of individual spectra, and moves to a home position at the end of the day. Among the scientific aims is Zeeman–Doppler imaging of the Sun as a star over the next activity cycle. Our first‐light application detects a clear Stokes‐V/I profile with a full amplitude of 1×10−4$$ 1\times {10}^{-4} $$ on, for example, October 13, 2023, suggesting a solar disk‐averaged line‐of‐sight net magnetic field of +0.37±0.02 G. Comparison of this value with a contemporary full‐disk line‐of‐sight magnetogram suggests an unsigned mean field of about ≈13 G. [ABSTRACT FROM AUTHOR]

Grazing transiting systems are rare and difficult to parameterize due to their partial transit geometry. We investigated a sample of 43 nearly‐grazing to fully‐grazing transiting exoplanetary systems, using datasets provided by the Transiting Exoplanet Satellite Survey (TESS), aiming first to refine major system parameters. We focus on the two parameters, impact parameter b$$ b $$ and planetary radius Rp$$ {R}_{\mathrm{p}} $$, through a comparison of TESS light curves with ground‐based light curves. We investigate if there is a potential systematic trend between ground‐based and space‐based investigations that would possibly lead to a redefinition of the grazing nature of those exoplanetary systems. Our results have shown that the b$$ b $$ value is confirmed for most of the systems within 2σ$$ 2\sigma $$, and refined significantly for Kilodegree Extremely Little Telescope (KELT)‐8 b, while the uncertainty on b$$ b $$ was improved for five systems with b>0.8$$ b>0.8 $$. The Rp$$ {R}_{\mathrm{p}} $$ measurements of four systems were successfully refined, while the uncertainty of Rp$$ {R}_{\mathrm{p}} $$ was improved for the majority of exoplanets with b>0.9$$ b>0.9 $$. Furthermore, a systematic trend is more pronounced for systems with b>0.9$$ b>0.9 $$, where there is a mean overestimation on the ground‐based derived Rp$$ {R}_{\mathrm{p}} $$ by 0.15RJ$$ 0.15{R}_{\mathrm{J}} $$. We concluded eventually that from our sample only five systems are truly grazing, while four systems that were considered as grazing are not. [ABSTRACT FROM AUTHOR]

A spectroscopic investigation of the lithium resonance doublet in ξ Boo A and ξ Boo B in terms of both abundance and isotopic ratio is presented. We obtained new R = 130,000 spectra with a signal‐to‐noise ratio (S/N) per pixel of up to 3200 using the 11.8 m LBT and PEPSI. From fits with synthetic line profiles based on 1D‐LTE MARCS model atmospheres and 3D‐NLTE corrections, we determine the abundances of both isotopes. For ξ Boo A, we find A(Li) = 2.40 ± 0.03 dex and 6Li/7Li <1.5 ± 1.0% in 1D‐LTE, which increases to ≈2.45 for the 3D‐NLTE case. For ξ Boo B we obtain A(Li) = 0.37 ± 0.09 dex in 1D‐LTE with an unspecified 6Li/7Li level. Therefore, no 6Li is seen on any of the two stars. We consider a spot model for the Li fit for ξ Boo B and find A(Li) = 0.45 ± 0.09 dex. The 7Li abundance is 23 times higher for ξ Boo A than the Sun's, but three times lower than the Sun's for ξ Boo B while both fit the trend of single stars in the similar‐aged M35 open cluster. Effective temperatures are redetermined from the TiO band head strength. We note that the best‐fit global metallicities are −0.13 ± 0.01 dex for ξ Boo A but +0.13 ± 0.02 dex for ξ Boo B. Lithium abundance for the K5V benchmark star 61 Cyg A was obtained to A(Li) ≈ 0.53 dex when including a spot model but to ≈0.15 dex without a spot model. [ABSTRACT FROM AUTHOR]

First‐light spectra of the Sun as a star taken by SDI‐POL, the Solar Disk Integration POLarimeter feeding the PEPSI night‐time spectrograph at the LBT. The top panel shows the full wavelength range (383 ‐ 907 nm) covered by SDI‐POL. The color of the Stokes I spectra indicates the individual cross dispersers; dark blue (=CD 1) to dark red (=CD 6). The line at the bottom represents the normalized Stokes V Q & U signal on the same intensity scale as Stokes I. The bottom panel is a zoom into the spectral region around the sodium D lines. The top spectrum is again Stokes I (plotted are dots per CCD pixel connected by a line), the bottom spectra are Stokes V Q U shifted by ‐0.10 in intensity and expanded by a factor 200 in scale with respect to Stokes I. The I Q U spectrum was taken on UT May 20, 2022, the V‐spectrum on UT June 22, 2023. The first‐light application detects a clear Stokes V/I profile indicative of a tiny but significant solar disk‐averaged line‐of‐sight net magnetic field of +0.37±0.02 Gauß on Oct. 13, 2023, as reported in the article by Strassmeier et al., this issue, e240033. [ABSTRACT FROM AUTHOR]

The strong chromospheric absorption lines Ca ii H & K are tightly connected to stellar surface magnetic fields. Only for the Sun, spectral activity indices can be related to evolving magnetic features on the solar disk. The Solar Disk‐Integrated (SDI) telescope feeds the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) of the Large Binocular Telescope (LBT) at Mt. Graham International Observatory, Arizona, U.S.A. We present high‐resolution, high‐fidelity spectra that were recorded on 184 & 82 days in 2018 & 2019 and derive the Ca ii H & K emission ratio, that is, the S‐index. In addition, we compile excess brightness and area indices based on full‐disk Ca ii K‐line‐core filtergrams of the Chromospheric Telescope (ChroTel) at Observatorio del Teide, Tenerife, Spain and full‐disk ultraviolet (UV) 1600 Å images of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). Thus, Sun‐as‐a‐star spectral indices are related to their counterparts derived from resolved images of the solar chromosphere. All indices display signatures of rotational modulation, even during the very low magnetic activity in the minimum of Solar Cycle 24. Bringing together different types of activity indices has the potential to join disparate chromospheric datasets yielding a comprehensive description of chromospheric activity across many solar cycles. [ABSTRACT FROM AUTHOR]

The article is a letter from the editor of Astronomische Nachrichten (AN), a scientific journal in the field of astronomy. The editor reflects on the journal's long history and the changes in scientific publishing. They express their appreciation for concise and freely accessible research papers that have been peer-reviewed. The editor highlights the recent editorial changes, including the use of a submission platform and open access as part of the European DEAL treaty. The journal welcomes submissions in various fields of astronomy and related studies. The letter concludes with contact information for the editorial team. [Extracted from the article]

We present our final orbit for the late‐type spectroscopic binary Henry Draper one (HD 1). area total of 553 spectra from 13 years of observations are used with our robotic STELLA facility and its high‐resolution echelle spectrograph SES. Its long‐term radial velocity stability is ≈50 m s−1. A single radial velocity of HD 1 reached an rms residual of 63 m s−1, close to the expected precision. Spectral lines of HD 1 are rotationally broadened with a v sin i of 9.1 ± 0.1 km s−1. The overall spectrum appears single‐lined and yielded an orbit with an eccentricity of 0.5056 ± 0.0005 and a semiamplitude of 4.44 km s−1. We constrain and refine the orbital period based on the SES data alone to 2, 318.70 ± 0.32 days, compared to 2, 317.8 ± 1.1 days when including the older dataset published by DAO and Cambridge/Coravel. Owing to the higher precision of the SES data, we base the orbit calculation only on the STELLA/SES velocities so as to not degrade its solution. We redetermine astrophysical parameters for HD 1 from spectrum synthesis and, together with the new Gaia DR‐2 parallax, suggest a higher luminosity than published previously. We conclude that HD 1 is a slightly metal‐deficient K0 III‐II giant 217 times more luminous than the Sun. The secondary remains invisible at optical wavelengths. We present evidence for the existence of a third component. [ABSTRACT FROM AUTHOR]

Ballistische Messkammer with 10k CCD's (BMK10k) central goal is supporting the upcoming PLAnetary Transits and Oscillation of stars (PLATO) mission by reducing its number of false positives (planet‐compatible transit candidates but not planets at the end). For Kepler, the number of false positives had been estimated to still be about 10%. Understanding the PLATO false alarm rate is not as straightforward, and preparatory data from the ground will dramatically improve the target selection and minimize the number of false positives. We aim to identify the target contamination for every PLATO target and initially provide well‐sampled light curves of all detectable contaminants in the long‐duration southern PLATO field. Thereby, it will be possible to identify background eclipsing binaries and rotating spotted stars with periods between 1 hr and 100 days down to 17–18th mag. This will be achieved with a dedicated robotic telescope with one of the world's largest CCDs with the smallest pixels, enabling a field of view of 52.5 square degrees with a sampling of 2.5″/pix. Auxiliary science is also foreseen and will focus on the period–mass relation of Ptolemy's cluster (M7). In this paper, we describe the entire telescope system and show initial commissioning data. [ABSTRACT FROM AUTHOR]

The effect of these open access initiatives becomes evident in an increased number of open access articles in AN as well as increased usage numbers. Finally, AN entered the article open access era as it benefits from a number of agreements Wiley has in place with institutions and funders to help authors publish open access and ensure compliance with open access policies. Authors from an institution affiliated with an open access deal may publish primary research and review articles open access at no charge to the author. [Extracted from the article]

Last year's volume of I AN i featured 114 peer-reviewed research articles with a total of over 800 pages. The last issue of the year saw the combined proceedings of STARS2019 and SMFNS2019 in Havana, Cuba. In addition, all articles of the first issue of each year can be downloaded free of charge, as can all articles labelled "Editor's Choice", which are often additionally featured with a color image on the front cover. [Extracted from the article]

An introduction is presented in which the editor discusses various reports within the issue on topics including energy neutrinos, mean-field dynamos, and star formation.

An introduction is presented in which the editor discusses the publication of the three interdisciplinary meetings on astronomy and astrophysics in a single issue, the quick turn-around of an article from submission to publication, and submission of articles.