<P> The Persian astronomer Abū Rayhān al - Bīrūnī (973--1048) proposed that the Milky Way is "a collection of countless fragments of the nature of nebulous stars". The Andalusian astronomer Avempace (d 1138) proposed the Milky Way to be made up of many stars but appears to be a continuous image due to the effect of refraction in Earth's atmosphere, citing his observation of a conjunction of Jupiter and Mars in 1106 or 1107 as evidence . Ibn Qayyim Al - Jawziyya (1292--1350) proposed that the Milky Way is "a myriad of tiny stars packed together in the sphere of the fixed stars" and that these stars are larger than planets . </P> <P> According to Jamil Ragep, the Persian astronomer Naṣīr al - Dīn al - Ṭūsī (1201--1274) in his Tadhkira writes: "The Milky Way, i.e. the Galaxy, is made up of a very large number of small, tightly clustered stars, which, on account of their concentration and smallness, seem to be cloudy patches . Because of this, it was likened to milk in color ." </P> <P> Actual proof of the Milky Way consisting of many stars came in 1610 when Galileo Galilei used a telescope to study the Milky Way and discovered that it is composed of a huge number of faint stars . In a treatise in 1755, Immanuel Kant, drawing on earlier work by Thomas Wright, speculated (correctly) that the Milky Way might be a rotating body of a huge number of stars, held together by gravitational forces akin to the Solar System but on much larger scales . The resulting disk of stars would be seen as a band on the sky from our perspective inside the disk . Kant also conjectured that some of the nebulae visible in the night sky might be separate "galaxies" themselves, similar to our own . Kant referred to both the Milky Way and the "extragalactic nebulae" as "island universes", a term still current up to the 1930s . </P> <P> The first attempt to describe the shape of the Milky Way and the position of the Sun within it was carried out by William Herschel in 1785 by carefully counting the number of stars in different regions of the visible sky . He produced a diagram of the shape of the Milky Way with the Solar System close to the center . </P>

Which of the following is not a major component of the milky way galaxy