Rebecca Oppenheimer

As a kid growing up in New York City, Rebecca Oppenheimer always wanted to study stars and planets. She never dreamed she would someday discover an entirely new kind of object. In 1995, she observed a small, dim object that was neither a planet nor a star. It is called a brown dwarf. This observation shows us that there are still things left to be discovered in the universe. Rebecca also studies faraway planets, and dying stars called white dwarfs.

Like stars and planets, brown dwarfs form in dense clouds of gas and dust. A brown dwarf is:

less massive than both stars and planets

more massive than both stars and planets

less massive than stars and more massive than planets

Are you right?

Correct!

Unlike a planet, a brown dwarf has enough mass to start nuclear fusion in its core. But since it has far less mass than a star, that nuclear fusion is very limited and can only last for millions of years. Most stars burn for billions of years.

Rebecca studies planets that orbit stars other than the Sun. These planets are called:

exoplanets

interplanets

microplanets

Are you right?

Correct!

"Exo" means outside, so an exoplanet is a planet that orbits a star outside of our Solar System. As of 2009, over 350 exoplanets have been discovered!

Rebecca Oppenheimer

“

It was so exciting when we first discovered the brown dwarf. You feel like, wow, there's all this stuff out there and we just found something new! Astronomy is like that. There is so much more to be found.

„

Astrophysicists like Rebecca can determine what a distant object is made of from its light.

Fact

Fiction

Fact

This light reveals the object's temperature and chemistry. Astrophysicists use telescopes to capture different wavelengths of light, from visible light to X-rays and microwaves.

The universe contains many more stars like our Sun than brown dwarfs.

Fact

Fiction

Scientists think that for every star like our Sun, there are hundreds of brown dwarfs.

Hometown: New York, NY
Job: Associate Curator & Prof. of Astrophysics
Education: PhD, California Institute of Tech.
Studies: brown dwarfs and exoplanets
Research Locations: Rebecca uses telescopes all over the world, in places like California, Hawaii, Chile, Japan, and the Canary Islands.
Cool Fact: Rebecca helps develop the Digital Universe, a large-scale, three-dimensional map that lets users "fly" through the universe.

Image credits: courtesy of AMNH / D. Finnin.