GD 61 facts for kids

GD 61 is a special type of star called a white dwarf. It is about 150 light-years away from Earth. You can find it in the constellation called Perseus.

This star has its own planetary system. GD 61 used to be a much bigger star, like our Sun but three times heavier! It was a "main sequence" star. Over time, it grew old and became a red giant. What is left now is a very dense and hot star. This white dwarf is about 70% the mass of our Sun. Its surface temperature is very hot, around 17,280 Kelvin. Scientists think GD 61 is about 600 million years old. This age includes its time as a main sequence star and as a white dwarf. GD 61 was first noticed in 1965 by astronomers looking for white dwarf stars.

Discovering GD 61's Past

Scientists learned a lot about GD 61 by studying it. They found that it was once a much larger star. It was similar to an A0V spectral type star. This means it was hotter and brighter than our Sun. As stars get older, they change. GD 61 went through a "red giant" phase. During this time, it expanded greatly. Eventually, it shed its outer layers. What remained was the small, dense core we see today. This core is the white dwarf.

An Asteroid with Water

In 2013, scientists made an amazing discovery in the GD 61 system. They found an asteroid that contains water! This was the first time water, either solid or liquid, was found on an extrasolar object. An extrasolar object is one outside our own Solar System.

What the Asteroid Tells Us

This asteroid is very special. About 26% of its mass is water. This is similar to the amount of water found in Ceres, a dwarf planet in our Solar System. This discovery suggests something very exciting. It means that a planet, possibly like Earth with a rocky surface, might have existed in the GD 61 system in the past.

The asteroid could be a piece of this old planet. It might now be part of a field of space rocks left over from when that planet broke apart. If such a planet existed, it would have had both a rocky surface and water. These are two very important things needed for life to exist.

How Scientists Studied It

Researchers used the Cosmic Origins Spectrograph on the Hubble Space Telescope to study the asteroid. This tool helps them figure out what things in space are made of. They found the elements magnesium, silicon, iron, and oxygen. These are all common parts of rocky planets.

However, they found a lot more oxygen than they expected. They also found less carbon. This extra oxygen was a big clue. It meant that there had to be water present in the asteroid.

Related pages

• 24 Themis, the first Solar System asteroid found to have liquid water

See also

In Spanish: GD 61 para niños