University of British Columbia cosmology student Michelle Kunimoto has found 17 new planets, including a conceivably habitable, Earth-sized world, by sifting through information assembled by NASA’s Kepler mission.

Over its original four-year mission, Kepler satellite searched for planets, particularly those that lie in the “Habitable Zones” of their stars, where liquid water could exist on a rocky planet’s surface.

The discoveries, published in The Astronomical Journal, incorporate one such especially uncommon planet. Authoritatively named KIC-7340288 b, the planet found by Kunimoto is only 1 ½ times the size of Earth—sufficiently small to be viewed as rocky, rather than gaseous like the giant planets of the Solar System—and in the habitable zone of its star.

“This planet is about a thousand light-years away, so we’re not getting there anytime soon!” said Kunimoto, a Ph.D. candidate in the department of physics and astronomy. “But this is a really exciting find since there have only been 15 small, confirmed planets in the Habitable Zone found in Kepler data so far.”

The planet has a year that is 142 ½ days long, orbiting its star at 0.444 Astronomical Units (AU, the distance between Earth and Sun) – only greater than Mercury’s orbit in Solar System, and gets about 33% of the light Earth gets from the Sun.

Of the other 16 new planets found, the smallest is just 66% the size of Earth—one of the smallest planets to be found with Kepler up until this point. The rest range in size up to eight times the size of Earth.

Kunimoto is no stranger to finding planets: she previously found four during her college degree at UBC. Presently working on her Ph.D. at UBC, she utilized what is known as the “transit method” to search for the planets among the about 200,000 stars saw by the Kepler mission.

“Every time a planet passes in front of a star, it blocks a portion of that star’s light and causes a temporary decrease in the star’s brightness,” Kunimoto said. “By finding these dips, known as transits, you can start to piece together information about the planet, such as its size and how long it takes to orbit.”

Kunimoto additionally worked together with UBC alumnus Henry Ngo to acquire razor-sharp follow-up pictures of some of her planet-hosting stars with the Near InfraRed Imager and Spectrometer (NIRI) on the Gemini North 8-meter telescope in Hawaii.

“I took images of the stars as if from space, using adaptive optics,” she said. “I was able to tell if there was a star nearby that could have affected Kepler’s measurements, such as being the cause of the dip itself.”

Notwithstanding the new planets, Kunimoto had the option to watch a great many known Kepler planets utilizing the transit-method and will be reanalyzing the exoplanet census as a whole.

“We’ll be estimating how many planets are expected for stars with different temperatures,” said Kunimoto’s Ph.D. supervisor and UBC Professor Jaymie Matthews. “A particularly important result will be finding a terrestrial Habitable Zone planet occurrence rate. How many Earth-like planets are there? Stay tuned.”