Green star discovered in Milky Way

Astronomers have identified what may be the first known green star in the Milky Way, named WD J1330+6435. This star is located about 280 light-years from Earth and has a surface temperature of approximately 4,000 °C.

Star’s color caused by atmospheric elements

The star appears green due to elements like calcium, lithium, and sodium in its atmosphere. These elements absorb light in the orange part of the spectrum, leaving a green glow that makes the star appear green to observers.

Discovery challenges star color assumptions

The finding challenges previous ideas about the colors of white dwarfs, which are dense remnants of dead stars. Traditionally, a star’s color was thought to depend mainly on its surface temperature, with hotter stars appearing blue and cooler ones red.

Color depends on temperature and composition

The study shows that both temperature and chemical composition can influence a star’s color. For example, carbon-rich white dwarfs may appear pink or purple, while those enriched by asteroid and comet debris may appear yellow. The coldest white dwarfs often have a cyan or pale blue tint.

Green star is rare and unexpected

WD J1330+6435 is notable for its green appearance, a color the researchers describe as unexpected. Among the 151 white dwarfs within 65 light-years of Earth, only five had atypical colors, and none were previously identified as green. The study estimates that about one in 30 white dwarfs in the universe may have an unusual color.