Physics professor Victor Zarate gave a lecture about the physics of stars to a room full of math and science majors on March 11.

Every seat was taken up during the hour long lecture, when Zarate utilized an intensive slideshow to display the physical makeup of the brightest stars in our sky.

The lecture was mostly occupied by Zarate’s Physics 410 classes, who received extra credit for attending.

Zarate began by discussing the density of the sun, and the characteristics of its surface.

Students eagerly took notes throughout the lecture, as there were no shortage of valuable equations shown on Zarate’s slides.

Zarate frequently paused to help students along with the equations to help them understand.

An American River College math major who attended the lecture, Jeremy Bauer, pointed out how hard it was to keep up.

“It’s a lot to take in, and I haven’t taken 410 yet, so I was a little lost at times during [the lecture],” said Bauer. “It fascinated me, but I still have a lot more math to take.”

“So what is a star?” Zarate asked frequently. “Think about it from a physics standpoint.”

A star has spherical symmetry, and exists only when there is equal pressure, temperature and density in that sphere.

Zarate’s slides shown during the lecture informed the audience that the biggest star in our solar system is the Sun, and 95 percent of its mass is concentrated in its center.

The remaining 5 percent is near its surface, and is the luminescent and fiery glow that we see from Earth.

Zarate emphasized how critical Newton’s first law of hydrostatic equilibrium is to understanding how stars function.
“The pressure of a star must balance the gravity,” Zarate said. “Those things aren’t just floating in the sky, even though it looks that way.”