The Milky Way is a barred spiral galaxy with a D 25 isophotal diameter estimated at 26.8 ± 1.1 kiloparsecs (87,400 ± 3,600 light-years), [10] but only about 1,000 light-years thick at the spiral arms (more at the bulge).

2017年11月8日 · Using infrared images from NASA’s Spitzer Space Telescope, scientists have discovered that the Milky Way’s elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to …

5 天之前 · Milky Way Galaxy - Structure, Dynamics, Stars: The first reliable measurement of the size of the Galaxy was made in 1917 by American astronomer Harlow Shapley. He arrived at his size determination by establishing the spatial distribution of globular clusters.

5 天之前 · Milky Way Galaxy, large spiral system consisting of several hundred billion stars, one of which is the Sun. It takes its name from the Milky Way, the irregular luminous band of stars and gas clouds that stretches across the sky as seen from Earth.

2021年9月23日 · The first clue to the shape of the Milky Way comes from the bright band of stars that stretches across the sky (and, as mentioned above, is how the Milky Way got its name). This band of stars can be seen with the naked eye in places with dark night skies.

2022年2月25日 · As the Milky Way appears to us as the long stripe across the sky, it means its shape is more likely a disk we see edge-on. We also can find the bulge at the center, and from observing the other galaxies, we know that the spiral ones are disks with central bulges.

2024年3月29日 · The traditional shape people think of when they hear the Milky Way galaxy is a spiral galaxy with four major spiral arms extending out from a thick central bulge of stars. But this traditional portrayal is not as accurate as people thought.

The part of the Milky Way containing the Sun is the disk, which is a thick platter of stars, gas, and dust about 100,000 light-years across. The galaxy’s spiral arms are part of this disk, where the youngest and brightest stars of the galaxy live.

2024年1月15日 · Through these techniques, we know that the Milky Way has at least two prominent spiral arms, and those arms are anchored on a central bar- or peanut-like core in a giant S shape.

The Milky Way has a diameter of 26.8 ± 1.1 kiloparsecs (87,400 ± 3,600 light-years) as measured using the D 25 isophote, [17] [18] [19] and is a barred spiral galaxy. The idea that the Milky Way is made of stars goes back to the Ancient Greek philosopher Democritus. [16]