A team of scientists led by Rice University astronomer Christopher Johns-Krull has discovered a giant planet orbiting a very young star about 450 light-years away.
This illustration shows a gas giant exoplanet orbiting its parent star. Image credit: NASA / ESA / STScI / L. Calcada.
Astronomers estimate that the newfound planet, named CI Tau b, is 11.3 times more massive than Jupiter. It orbits its host star, known as CI Tau, once every 9 days.
The star itself has a mass about 80 percent of the Sun’s. At two million years old, it is so young that it still retains a disk of circumstellar gas and dust.
CI Tau b was found with the radial velocity method, a planet-hunting technique that relies upon slight variations in the velocity of a star to determine the gravitational pull exerted by nearby planets that are too faint to observe directly with a telescope.
“For decades, conventional wisdom held that large Jupiter-mass planets take a minimum of 10 million years to form,” Dr. Johns-Krull said.
“That’s been called into question over the past decade, and many new ideas have been offered, but the bottom line is that we need to identify a number of newly formed planets around young stars if we hope to fully understand planet formation.”
The discovery resulted from a survey begun in 2004 of 140 candidate stars in the star-forming region Taurus-Auriga.
“This result is unique because it demonstrates that a giant planet can form so rapidly that the remnant gas and dust from which the young star formed, surrounding the system in a Frisbee-like disk, is still present,” said co-author Dr. Lisa Prato, an astronomer at Lowell Observatory.
“Giant planet formation in the inner part of this disk, where CI Tau b is located, will have a profound impact on the region where smaller terrestrial planets are also potentially forming.”
The research paper reporting this discovery has been accepted for publication in the Astrophysical Journal. The paper is also publicly available at arXiv.org.
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Christopher M. Johns-Krull et al. 2016. A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau. ApJ, accepted for publication; arXiv: 1605.07917
