Excesso no infravermelho em estrelas análogas rotacionais do sol: à procura de exo-cinturões de asteroides

Abstract

Observations of circunstellar matter disks provide a powerful tool for our understanding of the dynamic of planetary systems. Analogs to the Solar System asteroid belts, such disks result, mainly, from the collision of remaining solid material from the planetary formation process. Even if the current literature describe the presence of circunstellar disk in hundreds of Main Sequence stars, its detection around stars similar to the Sun is still very uncommom. In this context, the present study is focused on the search for debris disk orbiting stars with superficial physical parameters similar to the solar values, including, particularly, rotation period, from photometric observations in the infrared, in the 3.4, 4.6, 12 and 22 µm bands, made by the space mission Wide-field Infrared Survey Explorer (WISE). A sample of 881 stars was defined with effective temperature, metallicity, gravity and rotation period similar to the solar values. These stars, defined here as rotational analog to the Sun, have well-determined rotation period, calculated from photometric modulation identified in light curves obtained by the space telescope Kepler. Six stars, KIC 1868785, KIC 7267949, KIC 7435796, KIC 10533222, KIC 11352643, and KIC 11666436, present clear signs of infrared excess, revealing the presence of circunstellar matter orbiting them. The disks of matter detected are much more dense and luminous than the Solar System zodiacal dust, pointing to an origin associated to recent violent events.