To identify long-period variable (LPV) stars in IC 10—the nearest starburst galaxy of the Local Group—we conducted an optical monitoring survey using the 2.5 m Isaac Newton Telescope with the wide-field camera (WFC) in the i band and V band from 2015 to 2017. We created a photometric catalog for 53,579 stars within the area of CCD4 of WFC (∼0.07

Context. The measurement of the tiny temporal evolution in the redshift of distant objects, the redshift drift, is a powerful probe of universal expansion and cosmology. Aims. We performed the first steps towards the measurement of such an effect using the Lyman-α forest in the spectra of bright quasars as a tracer of cosmological expansion. Our

We compare the internal stellar structures of central galaxies in the TNG50 and TNG100 simulations and field galaxies in the CALIFA survey. The luminosity fractions of the dynamically cold, warm, and hot components in both TNG50 and TNG100 galaxies exhibit general consistency with those observed in CALIFA galaxies. For example, they all exhibit a

We present the polarization spectra of the nucleus of 3C 270. We confirm that the polarization angles of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux spectrum resembles the total flux spectrum, with

We survey 223 916 auroral records from the Northern hemisphere observed between 1650 January and 2024 July, making full allowance for the secular change in the geomagnetic field. We generate criteria for defining extreme auroral events that are met on 0.015 per cent and 0.023 per cent of nights since 1650 and 1790, respectively. After discussing

Episodic accretion is a fundamental process in the build-up of the stellar mass. EX Lupi-type eruptive young stars (EXors) represent one of the main types of episodic accretion. We study the recently discovered EXor Gaia23bab during its 2023 outburst. We obtained optical and near-infrared photometry and spectroscopy to probe the variation of the