By Chloe O.

Nebula The nebula is an interstellar cloud of dust, hydrogen gas, helium gas and plasma. Many nebulae form from the gravitational collapse of gas in the interstellar medium also known as ISM, while the material collapses under its own weight, huge stars may form in the center, and their ultraviolet radiation ions the surrounding gas. The Triangulum Emission Garren Nebula

Protostar Protostar is a large object that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. Its an early stage of the formation of a star. It is the baby star. Small protostar- a brown dwarf too small to create enough heat for fusion.

Main Sequence Main sequence is a continuous line of stars that appear on plots of stellar color versus brightness. The protostar gains enough weight to start fusion. All main sequence stars fuse hydrogen. During this stage, it is located along the main sequence at a position determined primarily by its weight, but also based on its chemical composition and other factors. Hertzsrung-Russell diagrams for two open clusters.

Red Giant The red giant is a giant star full of light with low weight that is in a late phase. It is a main sequence star and when it runs out of hydrogen, it starts fusing helium. It is tens to hundreds times larger than the sun. the main sequence stars of spectral types are believed to become red giants. The sun compared to the size during it’s red giant phase.

Planetary Nebula Planetary nebula is an emission nebula containing a glowing shell of gas and plasma formed by specific types of stars when they die. At the end of the red giant phase, the outer layers of the star are expelled via pulsations and strong stellar winds. Eskimo Nebula

White Dwarf The white dwarf is a small star composed mostly of electron-degenerate matter. They tend to be very dense. After the hydrogen-fusing lifetime of main sequence star of low or medium weight ends, it will expand to a red giant which fuses helium to carbon and oxygen in its core by the triple-alpha process. Its weight is equal to.5 of the sun, but size of earth left of core of a star. An image of a white dwarf taken by a Hubble Space Telescope.

Black Dwarf Black dwarf is a hypothetical stellar remnant. It is created when a white dwarf becomes sufficiently cool to no longer emit significant heat or light. It takes trillions of years till a white dwarf no longer emits light.

Nebula An interstellar cloud of dust, hydrogen gas, helium gas, and plasma. Many nubulae form from gravitational collapse of gas in the interstellar medium. While the material collapses under its own weight, huge stars may form in the center, and their ultraviolet radiation ionses the surrounding gas. Omega nebula

Protostar The protostar is a large object that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. It’s the early stage of a formation of a star. Protostar

Massive Main Sequence The massive main sequence stars fuse hydrogen a lot quicker than small or medium stars. This is a diagram a main sequence.

Red Super Giant The red supergiant is a really big star of spectral type K or M. They are the largest stars in the universe in terms of volume. Stars with more than about ten solar masses after burning their hydrogen become red super giants during their helium burning phase. Cross section of a red supergiant.

Supernova It is a stellar explosion. They are very luminous and cause a burst of radiation that often shortly outshines an entire galaxy, before fading from view over several of weeks or months. Fusion stops, the star collapses and makes huge explosion. Optical compilation image of Kepler’s Supernova Remnant

Neutron Star It is a type of remnant that can result from the gravitational collapse of a massive star during a type ll, type lb, or type lc supernova event. It is an extremely dense core of a leftover star after supernova. It is 15-5 miles in diameter and has a weight of times that of the sun. Neutron star in visible light,

Black Hole The black hole is a region of space where the gravitational field is so powerful that absolutely nothing can escape. The black hole has a one-way surface, known as an event horizon, which objects can fall, but nothing can come out. It is called black because all the light that hits it is absorbed. Nothing is reflected. A view of the black hole in front of the Large Magellanic Cloud.

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