Astronomy: Supermassive black hole at center of Milky Way has mass of 4.6 million suns – The Columbus Dispatch

Kenneth Hicks| For The Columbus Dispatch USA TODAY NETWORK

The American Physical Society held their annual conference this past week, withallpresentations givenonZoom.Many new results in the area of astrophysics were presented, ranging from black holes to gravitational waves(as well asseveralother topics).

For me,a talk onasupermassive black hole at the center of ourMilky Way galaxy was the most interesting. Only 20 years ago, there was scant evidence that such an object existed in our galaxy.But now, withadvances in technology,the evidence is overwhelming.The black holetherehasthemassofamind-boggling4.6 million suns.When you consider that our sun is about a half-million times the mass of the entire Earth, then thisblack hole is more than atrilliontimes(or 1,000,000,000,000)more massive than the Earth.

So how can astronomers determine such a huge mass?It turns out that you can calculate the mass of any stellar object just by measuring the orbit of another body going around it.For example, we can measure the mass of the sun just by knowing the Earths orbit. Or we canfindthe mass of Jupiter just by measuring the orbit ofone ofJupiters moons.Its that simple along with a bit of math.

Advances in technology have madeitpossibleto get the mass of our galaxys black hole.There aretwoprimarycontributions.One is from building large telescopes that are designed to look at infrared lightin the night sky.

Although infrared light is invisible to our eyes, electronic sensors(like those in your phones camera)can be built to detect infrared light.It turns out that our Milky Way has a lot of gas and dust between Earth and the center of the galaxy, about 25,800 light-yearsaway.But infrared light can penetrate the dust, giving a clear view of stars that orbit the black hole.

The second contribution is a technique called adaptive optics, where the telescope can make near-instantaneous adjustments to the shape of the telescopes reflecting mirror to compensate for distortions of light passing through the atmosphere.

Think of looking past the top of a hot barbeque.Youll see a wavy distortion due to the hot swirling air above. Similarly, the air above a telescope is constantly moving, and causing distortions in the stars it is viewing.

With the new technology, astronomers can now clearly see stars that orbit the black hole at the center of our galaxy. Now that we know if exists, the next question is:how diditget so massive?Thats a mystery that likely wont be solved for many years.It may take the next generation of astronomers to figure out the answer.

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Astronomy: Supermassive black hole at center of Milky Way has mass of 4.6 million suns - The Columbus Dispatch