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

The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid space mission has obtained near-infrared (NIR) spectra of millions of objects, including hundreds of ultracool dwarfs (UCDs). Euclid observations retrieve images and slitless spectra simultaneously. This observing mode marks a new era in the discovery of new objects, such as L- and T-type dwarfs, which can be found from direct identification through the H2O and CH4 absorption bands. NISP spectral resolution (R ∼ 450) is enough to classify the objects by the spectral type using known standard templates. Q1 provided more

The solar corona—the outermost layer of the Sun’s atmosphere—is extremely hot and very low in density. One of the main challenges in solar physics is understanding why the corona reaches temperatures of over a million degrees. This heating is believed to be closely related to the Sun’s magnetic field. However, quantifying the coronal magnetic field is difficult because the light emitted by the corona is extremely faint, and its polarization signals, which encode the information on the magnetic field, are subtle. Thanks to recent advances in technology, telescopes like the Daniel K. Inouye