The statement that astronomers have found many other stars surrounded by dark matter halos is not entirely accurate. While dark matter is believed to exist based on various observations and theoretical models, its direct detection and characterization remain elusive.
Dark matter is thought to be a form of matter that does not interact with light or other electromagnetic radiation, making it difficult to observe directly. Its presence is inferred through its gravitational effects on visible matter, such as stars and galaxies. Astronomers have observed the gravitational influence of dark matter on the rotation curves of galaxies and the distribution of matter in the universe, but detecting dark matter directly around individual stars is a challenging task.
When it comes to the Sun, astronomers have not directly observed a dark matter halo around it. The presence of dark matter in the vicinity of the Sun is inferred from large-scale observations of the dynamics of stars in our galaxy, the Milky Way. By studying the motion of stars and gas clouds in the galaxy, astronomers can estimate the total mass present in the region. The observed mass is found to be significantly greater than the mass accounted for by visible matter, suggesting the presence of dark matter.
However, precisely determining the distribution and nature of dark matter in the Milky Way is still an active area of research. Astronomers employ various techniques, including computer simulations and indirect observations, to study dark matter. While there have been suggestions that the Sun could be embedded in a dark matter halo, its direct observation remains challenging due to the weak interactions between dark matter and ordinary matter.
In summary, astronomers have not directly observed dark matter halos around individual stars, including the Sun. The presence of dark matter is inferred from its gravitational effects on visible matter at larger scales, such as galaxies and the dynamics of the Milky Way.