Nuclear star clusters are dense and compact stellar systems, with sizes of a few parsecs, found at the centers of many galaxies. Their formation is thought to be closely connected to the assembly history of their host galaxies, and astronomers think that these clusters contain important clues about how galaxies formed and evolved over cosmic time. Recent studies suggest that different formation pathways may operate in late- and early-type galaxies, but the dominant mechanisms and their dependence on galaxy morphology remain unclear. While most observational studies have focused on early-type
Solar wavefront sensing has been a challenge for astrophysical instrumentalists, due to the low contrast between the Sun and the sky background compared to night-time observations, which limits the performance of adaptive optics systems. Wavefront correction in solar physics requires the analysis of extended images; meanwhile, at night the displacement of a punctual object is analysed. This technique limits the spatial resolution, and therefore the accuracy in the wavefront reconstruction. To solve this problem, a new method of direct wavefront sensing without the need for image formation
Measuring galaxy sizes is essential for understanding how they were formed and evolved across time. However, traditional methods based on l ight concentration or isophotal densities often lack a clear physical meaning. A recent study from Trujillo+20 explores a more physically motivated definition: the radius R 1, where the stellar surface density falls to 1 solar masses per parsec square —roughly the threshold for gas to form stars in galaxies like the Milky Way. In this work, Arjona-Gálvez+25 uses over 1,000 galaxies from several state-of-the-art cosmological simulations (AURIGA, HESTIA