Ceres, Ring Nebula, and M33 Triangulum Galaxy

Observatory / Course Archives / ASTR 110 Fall 2019 / Pang

Ceres

Ceres is a dwarf planet in our solar system, meaning that it doesn't meet all the definitions of a planet. What makes Ceres a dwarf planet then? It turns out that Ceres does not dominate its orbit, its orbit is shared with thousands of asteroids in the asteroid belt. However, Ceres is the only dwarf planet located in the inner solar system. It is the largest object in the asteroid belt with a diameter of 945 km. A recent discovery of Ceres suggests that Ceres is wrinkling. As planets made of rock begin to cool, it contracts and begins to be denser. This process forms a thrust fault. Evidence of thrust faults leads to the suggestion that Ceres is shrinking and that it forms wrinkles on its surface.

Through the image above you can see that Ceres has a gray color with a lot of craters. This picture was taken through NASA's Dawn mission that observes Ceres. Images were taken through infrared spectra that gives new compositional data. This also confirms that the gravity of Ceres obtains its round surface despite all the craters. Among all the craters on Ceres, there are a few that have bright spots in it. For example, through the image above, the one that has a bright spot in the center is called Oxo. Research has shown that the bright material is made of salts. Another one named Occator is special than other craters because it contains white and blue colored material like it has overflood outward. This could have formed from "a fluid driven to the surface by a small amount of gas".

Ring Nebula

The Ring Nebula is a planetary nebula in the northern constellation of Lyra. Most nebulae are formed from a giant cloud of dust and gas that is thrown out by the explosion of a dying star that's on its way to being a white dwarf. The Ring Nebula showed above (Messier 57) is relatively close to Earth and fairly bright. It's about 2,570 light-years from Earth. From Earth's perspective, the Ring Nebula looks elliptical. However, it is actually shaped like a distorted doughnut with low-density material in the center that stretch it out both toward and away from us. All of the gas was expelled about 4,000 years ago. According to NASA, "The outer rings were formed when fast-moving gas slammed into slow-moving material". This also indicates that the outer rings were moving slower than the center.

The image shown above is a composite image. It combined visible-light observations from NASA'S Hubble Telescope with infrared data from Large Binocular Telescope in Arizona. The spectacular colorization of Ring Nebula M57 indicates its chemical composition in different stages. The darker blue in the center represents helium, the lighter blue is hydrogen, the yellow-green is doubly-ionized oxygen, and the red color is nitrogen and sulfur. The green lines in the nebula are called "forbidden lines", which occur only in very low density containing a few atoms per cubic centimeter.

Triangulum Galaxy

The Triangulum Galaxy is the third-largest member of the Local Group of galaxies. It's also one of the most distant objects that can be viewed with the naked eye with an apparent magnitude of 5.7. The name of the Triangulum Galaxy comes from where it can be spotted, which is in the constellation Triangulum. M33 Triangulum Galaxy is a spiral galaxy that's about 3 million light-years away from Earth. We can also tell that M33 is an unbarred spiral galaxy by looking at the center of the bulge. According to NASA, M33 and Andromeda galaxy are both moving toward our galaxy. This finding suggests that M33 could be involved in the impending collision between the Andromeda and Milky Way galaxies more than 4 billion years from now.

The blue color on the disk of the spiral galaxy indicates the formation of young stars. This also refers to the population I stars, which is more commonly found in the spiral arms. Regions with the formation of young stars mean that there is a lot of gas and dust. However, M33 Triangulum Galaxy seems like it's missing the usual bulge shape in the center. There's also a video from Launch Pad Astronomy that looks at pictures of M33 and explained information about its location, stellar formation, and how fast it forms new stars.