<Li> 3rd galactic quadrant--180 ° ≤ l ≤ 270 ° </Li> <Li> 4th galactic quadrant--270 ° ≤ l ≤ 360 ° (0 °) </Li> <P> The Sun is 25,000--28,000 ly (7.7--8.6 kpc) from the Galactic Center . This value is estimated using geometric - based methods or by measuring selected astronomical objects that serve as standard candles, with different techniques yielding various values within this approximate range . In the inner few kpc (around 10,000 light - years radius) is a dense concentration of mostly old stars in a roughly spheroidal shape called the bulge . It has been proposed that the Milky Way lacks a bulge formed due to a collision and merger between previous galaxies, and that instead it has a pseudobulge formed by its central bar . </P> <P> The Galactic Center is marked by an intense radio source named Sagittarius A * (pronounced Sagittarius A-star). The motion of material around the center indicates that Sagittarius A * harbors a massive, compact object . This concentration of mass is best explained as a supermassive black hole (SMBH) with an estimated mass of 4.1--4.5 million times the mass of the Sun . The rate of accretion of the SMBH is consistent with an inactive galactic nucleus, being estimated at around 6995100000000000000 ♠ 1 × 10 M y . Observations indicate that there are SMBH located near the center of most normal galaxies . </P>

List of planets in the milky way galaxy