| Abstract : | From Tycho Brahe's historic observations to the ongoing Transiting Exoplanet Satellite Survey (TESS) and James Webb Space Telescope's (JWST) latest high-resolution images, our curiosity has unveiled some of the universe's secrets. In the early 17th century, the revolutionary idea of Galileo to point a telescope to the sky showed that the Sun has spots. While Hale 1908b answered what these spots were by the 20th century, photometric and spectral data analysis revealed their presence on distant stars as well.
Understanding the surface features of pre-main sequence stars is essential as it affects the star’s overall properties, such as its rotation rate, and mass loss, and is even necessary in interpreting radial velocities measured by modern, extreme precision radial velocity spectrographs, particularly for exoplanet discoveries. For young stars, this analysis provides valuable insights into surface activity as they undergo accretion from their surroundings and further undergo planet formation. Currently, the Sun is the only spatially resolved star we have access to. For these distant stars, inferring surface features from photometric light curves remains our only option. Many of these light curves are variable, often due to star spots, faculae, and other surface features that rotate into and out of view throughout a stellar rotation. We did ensemble analysis on the TESS lightcurves that has been already resolved by various projects like CDIPS and PATHOS and incorporated the use of Gaussian processes to assess the probability of specific spots concentrated at certain latitudes. While in principle, we haven't located spots for a specific star, through our research we offer insights into spot patterns for young stars across the population. Through our research, we can comment on the effect of changing magnetic fields on stellar parameters by analyzing a few observation epochs of the same targets.
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