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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 $��600��m��s^{�-�1�}�$) 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 $��\lambda �/�4�$ 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 $��1�\times �{10}^{�-�4�}�$ 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.

In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal-poor and high proper-motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters: T_{eff =} 4700 ± 115 K, log g = 1.65 ± 0.32 cgs, [Fe/H] = −1.59 ± 0.04 dex, and a microturbulent velocity $��\xi �=�$ 1.58 ± 0.50 km s⁻¹ for HD 8724 and T_eff = 6100 ± 205 K, log g = 3.95 ± 0.35 cgs, [Fe/H] = −0.52 ± 0.05 dex, and $��\xi �=�$1.26 ± 0.50 km s⁻¹ for HD 195633. The ages were estimated using a Bayesian approach (12.25 Gyr for HD 8724 and 8.15 Gyr for HD 195633). The escape scenarios of these stars from 170 candidate globular clusters (GCs) in the Galaxy were also investigated because of their chemical and physical differences (HPM and metal-poor nature). Accordingly, the calculated probability of encounter (59%) for HD 8724 at a distance of five tidal radius suggests that star HD 8724 may have escaped from NGC 5139 ($��\omega �$ Cen), supported by its highly flattened orbit and may belong to a subpopulation of this GC. Conversely, HD 195633's kinematics, age, and metal abundances point toward an escape from the bulge GC NGC 6356.

The pulsating variable star Mira (o Ceti) was observed by David Fabricius (Frisia) in 1596 and 1609. We review suggested previous detections (e.g., China, Hipparchos). We analyze all Mira records from Fabricius in their historical context. Fabricius measured the separation of Mira to other stars to ±1.6−1.7′. From his texts, we derive a brightness (slightly brighter than Hamal) of ca. 1.9±0.1 mag and a color index B-V$��\simeq �$1.3−1.4 mag (‘like Mars’) for 1596 Aug 3 (Jul.). Mira started to fainten 19 days later and was observed until mid/late Oct. We show why such a red star cannot be followed by the naked eye until ca. 6 mag: For Mira's color at disappearance and altitude from Frisia, the limit is reduced by ca. 1.0 mag. Since Fabricius connected the Mira brightening with the close-by prograde Jupiter, he re-detected it only 12 years later, probably shortly before a relatively bright maximum—discoveries are strongly affected by biases. A Mira period of 330.2 days is consistent with both the oldest data (from Fabricius 1596 to Hevelius 1660) and the most current data (VSX 2004–2023), so that we see no evidence for secular period or phase shifts. (We also present Fabricius' observations of P Cygni in 1602.)

Type II supernovae (SNe II) have emerged as valuable cosmological probes, serving as alternative and independent tools to Type Ia supernova (SN Ia) cosmology. However, the Hubble diagram dispersion for SNe II is significantly larger than for SNe Ia. In this study, we investigate the SN II luminosity and the host galaxy velocity dispersion with the purpose of improving the scatter in the SN II Hubble diagram. We selected a sample of SNe II discovered by the Dark Energy Survey (DES), and we measured the spectra of their host galaxies using the VLT/FORS2 and Magellan-Baade/MagE spectrographs. From those galaxy spectra, we calculated the stellar velocity dispersion in the central region. Using the effective Sérsic radius from the DES imaging, we standardized the velocity dispersion values to a common aperture. From their i-band light curves, we determined a characteristic plateau brightness for our SNe. For this purpose, we developed an algorithm designed to parameterize the plateau phase. After computing the SN absolute magnitudes using the standard cosmology, we found a modest correlation with the host galaxy velocity dispersion ($��R^2�=�0.57�$). These findings could significantly contribute to SN II cosmology, paving the way for SNe II as more robust cosmological probes.

Color-magnitude diagram of the lower mass end of the Main Sequence of globular cluster NGC 6752, as derived from NIR images of a deep field observed under a HST Large Programme led by L.R.Bedin. Three main stellar populations can be reliably distinguished within this cluster. The three isochrones (blue, green, and red lines) were computed with different chemical compositions, adjusted to match the observed colors of the different generations of stars at an age of 12.63 Gy. In the lower left part of the plot, the corresponding isochrone for the White Dwarfs (at an age of 12.5 Gy) is shown in purple, together with the three WD candidates shown as orange crosses. For each isochrone, specific mass values are marked by labeled filled dots. A detailed analysis of the HST data and a discussion of possible scenarios for the formation of multiple stellar populations within NGC 6752 is presented in the article by Scalco et al., this issue e240018.

We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against) the existence of ancient planetary systems. The existing archival Hubble Space Telescope imaging data obtained $��\sim �18�$ years ago reach ultra-deep optical magnitudes ($��V�\sim �31�$) and allow us to derive a near-perfect separation between field and cluster members. We detect an apparent split in the lower part of the WD CS of NGC 6397. The red part of the WD CS, containing about 25% of the total, exhibits significant IR-excess of up to $��\Delta �m_{�F�322�W�2�}�\sim �0.5�$ mag. These infrared excesses require both theoretical and observational follow-ups to confirm their veracity and to ascertain their true nature.