[/caption]
Stars come in many shapes and sizes and they come in many colors. Some of the hottest stars in the Universe are blue giant stars. You see, the color of a star is defined by its temperature; the coolest stars are red, while the hottest ones appear blue. And the temperature of a star comes from its mass. The more massive a star, the hotter it’s going to be. Stars don’t get more more massive or hot than blue giant stars.
Blue giants blaze with a surface temperature of 20,000 Kelvin or more, and are extremely luminous. Just for comparison, a star like our Sun only has a surface temperature of about 6,000 Kelvin. A blue giant star can put out 10,000 times as much energy as the Sun. Astronomers categorize blue giants as type O or B stars, belonging to the luminosity class III. The can reach an absolute magnitude of -5 or -6.
The true monsters of the Universe are blue supergiant stars, like Rigel. These can be a blue star with surface temperatures of 20,000 – 50,000 Kelvin and can be 25 times larger than the Sun. Because they’re so large, and burn so hot, they use up their fuel very quickly. A middle-sized star like our Sun might last for 12 billion years, while a blue supergiant will detonate with a few hundred million years. The smaller stars will leave neutron stars or black holes behind, while the largest will just vaporize themselves completely.
We have written many articles about stars on Universe Today. Here’s an article that looks for the biggest star in the Universe.
Want more information on stars? Here’s Hubblesite’s News Releases about Stars, and more information from NASA’s imagine the Universe.
We have recorded several episodes of Astronomy Cast about stars. Here are two that you might find helpful: Episode 12: Where Do Baby Stars Come From, and Episode 13: Where Do Stars Go When they Die?
Last November, NASA's Lucy mission conducted a flyby of the asteroid Dinkinish, one of the…
Steven Hawking famously calculated that black holes should evaporate, converting into particles and energy over…
NASA has given the go-ahead for SpaceX to work out a plan to adapt its…
The JWST is astronomers' best tool for probing exoplanet atmospheres. Its capable instruments can dissect…
First light for the Vera Rubin Observatory (VRO) is quickly approaching and the telescope is…
A beautiful nebula in the southern hemisphere with a binary star at it's center seems…