How old is the universe? SDSU astronomy grad students work to find an answer

Astronomy graduate students at San Diego State University are in the middle of their semester doing something that, of course, is out of this world.

At an elevation of 6,100 feet, Mount Laguna Observatory is home to multiple telescopes, including the one these grad students are using to analyze something you can’t see with the naked eye.

They’re using the 1-meter telescope to get a closer look at supernovas.

“You don’t really get to do this every day,” Nissia Indradjaja, a graduate student in the program, said. “Even as an astronomer.”

For Indradjaja and her fellow grad students Zoe and Katan, in their astronomical techniques course, they’re operating this telescope remotely, miles away from Mount Laguna in their SDSU classroom.

“Yeah, it’s pretty cool stuff," she said.

Even cooler and complicated is how they’re using it.

“They’re measuring what’s called the Hubble Constant,” Professor Robert Quimby, who teaches the course, said. “This is a measure of the expansion rate of the universe.”

"If we want to understand everything that happened from the beginning of the universe to now, this is one of the key constants that we need to understand," Quimby added.

No easy task, but one that Quimby says can help answer this question: How was the universe formed?

“We’re doing that by observing supernovae, well type 1A supernovae,” Indradjaja said.

Using the 1-meter telescope and spectra data from another, they’re looking at exploding stars. In this case, according to Quimby, these are thermal nuclear explosions of white dwarf stars. So small, one wouldn’t be able to see it with the naked eye. Once they are discovered, students observe their brightness to see just how far away the supernovae are.

“We live in an expanding universe, so stars in our own galaxy, we’re all kind of in one little package but if you go to another galaxy – it turns out most other galaxies are actually moving away from us due to the expansion of our universe,” Quimby said.

Quimby says the farther you go from this universe, the faster this happens. For his students, they'll observe these supernovas for over a month and watch as they get to their brightest peaks before fading away.

“If you kind of turn that around, you could say, 'OK, well back in time everything was coming together into a point and that’s where we started, the Big Bang, so we’re trying to measure how far away things are expanding,” Quimby said.

While it’s practice now, these students could soon be answering the most fundamental question.

“And that gives us some indication of what the age of the universe is,” Quimby said.

According to SDSU, because of its location about 45 miles east of San Diego, Mount Laguna has a high percentage of clear nights making it one of the best sites to observe in the continental United States.