Since its 2009 launch, astronomers using the Kepler orbital observatory have found scientific confirmation of the existence of exoplanets - including the possibly Earth-like Kepler-452b - in other regions of our galaxy.
According to NASA’s website, the “Kepler Mission is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.”
Kunimoto’s findings were published in The Astronomical Journal on February 25.
“Our search returned 17 planet candidates (PCs) in addition to thousands of known Kepler Objects of Interest (KOIs), with a 98.8% recovery rate of already confirmed planets,” the study’s abstract explains, also noting that it identified one special planet, KIC-7340288 b.
What sets this planet apart from others is that it is both rocky and in the habitable zone. Rocky planets are composed mostly of silicate rocks or metals and are the ones that are closest to the sun within the solar system. According to Britannica.com, the habitable zone is the “orbital region around a star in which an Earth-like planet can possess liquid water on its surface and possibly support life.”
"This planet is about a thousand light-years away, so we're not getting there anytime soon!" Kunimoto told Phys.org, referring to KIC-7340288 b.
“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,” she added.
The findings also revealed that KIC-7340288 b has a year that is 142.5 Earth days long and is orbiting its star at a distance of 0.444 astronomical units, which is only slightly bigger than Mercury’s orbit. One astronomical unit is equal to 149.6 million kilometers and is approximately the distance from the Earth’s center to the sun’s center.
Out of the 16 other new planets discovered, the smallest one is only two-thirds the size of Earth and is one of the smallest planets discovered by the Kepler telescope to date. The remaining planets are around eight times the size of Earth.
Kunimoto told Phys.org that she uses the “transit method” to discover planets.
"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. 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 said.
Kunimoto also worked with UBC alumnus Henry Ngo to get images of some of the stars being orbited by the new planets using 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. 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,” Kunimoto told Phys.org.
Kunimoto also revealed that she plans to use the transit method to determine how many known Kepler planets are Earth-like.
"We'll be estimating how many planets are expected for stars with different temperatures," Jaymie Matthews, Kunimoto's PhD supervisor and a UBC professor, told Phys.org. "A particularly important result will be finding a terrestrial Habitable Zone planet occurrence rate. How many Earth-like planets are there? Stay tuned."