White dwarfs accreting planetary debris provide detailed insight into the bulk composition of rocky exoplanetesimals. However, only one Kuiper Belt analogue has been identified in that way so far. Here, we report the accretion of an icy extrasolar planetesimal on to white dwarf WD 1647+375 using ultraviolet spectroscopy from the Hubble Space

The Chromospheric LAyer SpectroPolarimeter missions, CLASP2 and CLASP2.1, demonstrated that the near-UV spectral region between 279.30 and 280.68 nm is suitable for studying the magnetism of the solar chromosphere. In particular, the spectropolarimetric observations in the Mg II h and k resonant doublet, Mn I 279.91 and 280.19 nm resonant lines

We present baryon acoustic oscillation (BAO) measurements from more than 14 million galaxies and quasars drawn from the Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2), based on three years of operation. For cosmology inference, these galaxy measurements are combined with DESI Lyman- α forest BAO results presented in a companion

We present the baryon acoustic oscillation (BAO) measurements with the Lyman- α ( Ly α) forest from the second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI) survey. Our BAO measurements include both the autocorrelation of the Ly α forest absorption observed in the spectra of high-redshift quasars and the cross-correlation of

The one-dimensional power spectrum P 1D of Lyα forest offers rich insights into cosmological and astrophysical parameters, including constraints on the sum of neutrino masses, warm dark matter models, and the thermal state of the intergalactic medium. We present the measurement of P 1D using the optimal quadratic maximum likelihood estimator

Giant low-surface-brightness (GLSB) galaxies represent an extreme class of disk galaxies characterized by exceptionally large sizes and low stellar densities. Their formation and evolutionary pathways remain poorly constrained, primarily due to the observational challenges associated with detecting their faint stellar disks. In this work, we