The system was flagged as an eclipse.
Mr Cukier's job was to examine variations in star brightness captured by Nasa's Transiting Exoplanet Survey Satellite (TESS) and upload them to TESS's citizen science project.
An exoplanet, according to Merriam-Webster, is a "planet orbiting a star that is not [Earth's] sun". "We don't have a large sample size of binary system planets". The event is called a transit, which TESS's cameras can capture. The New York teen joined a NASA program last summer and spotted an unknown planet orbiting two stars about 1,300 light-years away.
TOI 700 d is about 20 percent larger than Earth and orbits its star in 37 days.
As planets pass in front of stars, - known as a transit - it can help astronomers determine the location of planets.
Cukier's planetary finding was featured in a panel discussion on Monday at an American Astronomical Society meeting in Honolulu, the agency said, and a paper co-authored by the high school student has been submitted to a scientific journal.
Being in a star's habitable area means that a planet has temperatures that could permit liquid water to exist on the surface. Such measurements will be necessary to estimate whether it is a rocky planet like Earth, or a gassy one like Neptune.
Cukier had just finished his junior year when he started his internship at NASA's Goddard's Space Flight Center in Goddard, Md., last summer.
A few other similar planets have been discovered before, notably by the Kepler Space Telescope, but this is the first discovered by TESS, which was launched in 2018. "Future research would involve finding more planets", Wolf said. After Cukier notified NASA of what he saw, scientists used software called eleanor to confirm that the transits involved a planet and two stars.
The modeling team for TOI 700 d is led by Gabrielle Engelmann-Suissa. Experts have since explained that discoveries like this one are easier to make by sight rather than through utilising computers.
About three days into his internship, Cukier noticed a signal from a system named "TOI 1338". As per the space agency, one of the stars in the TOI 1338 system is about 10 per cent more massive than our Sun, while the other is cooler, dimmer and only one-third the Sun's mass.
These kinds of planets, called circumbinaries, are hard to identify. The first such discovery came in 1993.