K2 Finds Newborn Exoplanet Around Young Star

[bystander]

K2 Finds Newborn Exoplanet Around Young Star
NASA | JPL-Caltech | Ames | Kepler | 2016 June 20

[img3="This image shows the K2-33 system, and its planet K2-33b, compared to our own solar system. The planet has a five-day orbit, whereas Mercury orbits our sun in 88 days. The planet is also nearly 10 times closer to its star than Mercury is to the sun.
Credits: NASA/JPL-Caltech"]http://photojournal.jpl.nasa.gov/jpeg/PIA20691.jpg[/img3][hr][/hr]

Astronomers have discovered the youngest fully formed exoplanet ever detected. The discovery was made using NASA's Kepler Space Telescope and its extended K2 mission, as well as the W. M. Keck Observatory on Mauna Kea, Hawaii. Exoplanets are planets that orbit stars beyond our sun.

The newfound planet, K2-33b, is a bit larger than Neptune and whips tightly around its star every five days. It is only 5 to 10 million years old, making it one of a very few newborn planets found to date. ...

Planet formation is a complex and tumultuous process that remains shrouded in mystery. Astronomers have discovered and confirmed roughly 3,000 exoplanets so far; however, nearly all of them are hosted by middle-aged stars, with ages of a billion years or more. For astronomers, attempting to understand the life cycles of planetary systems using existing examples is like trying to learn how people grow from babies to children to teenagers, by only studying adults. ...

Discovered: Youngest Fully-Formed Exoplanet Ever
W. M. Keck Observatory | 2016 June 20

Newborn Exoplanet Discovered Around Young Star
California Institute of California | 2016 June 20

Discovery of Newborn Exoplanet Could Help Explain Planetary Evolution
University of Exeter | via EurekAlert | 2016 June 20

A Neptune-sized transiting planet closely orbiting a 5–10-million-year-old star - Trevor J. David et al

• Nature (online 20 June 2016) DOI: 10.1038/nature18293

[bystander]

Young Super-Neptune Offers Clues to the Origin of Close-In Exoplanets
National Optical Astronomy Observatory | 2016 June 20

[img3="K2-33 b, shown in this illustration, is one of the youngest exoplanets detected to date and makes a complete orbit around its star in about five days. These two characteristics combined provide new constraints for planet formation theories. K2-33 b could have formed farther out and quickly migrated inward. Alternatively, it could have formed in situ, or in place. Credit: NASA/JPL-Caltech/R. Hurt"]http://www.jpl.nasa.gov/spaceimages/ima ... _hires.jpg[/img3][hr][/hr]

A team of astronomers has confirmed the existence of a young planet, only 11 million years old, that orbits very close to its star (at 0.05 AU), with an orbital period of 5.4 days. Approximately 5 times the size of the Earth, the new planet is a “super-Neptune” and the youngest such planet known. The discovery lends unique insights into the origin of planetary system architectures.

An enduring puzzle about exoplanets is their prevalence at orbital distances much closer to their central stars than the planets in our own Solar System. How did they get there? One scenario holds that they were born and bred in the hot inner disk close to the star. Other scenarios propose that the close-in planet population originated in cooler climes, at distances beyond the orbit of the Earth, and migrated inward to where they now reside. Their migration may have been driven by interactions with either the natal disk, with other planets in the same planetary system, or with more distant stars.

These scenarios can be tested observationally by searching for young planets and studying their orbits. If the close-in population formed in place or migrated in through interactions with the natal disk, they reach their final orbital distances early on and will be found close in at young ages. In comparison, migrating a planet inward through interactions with other planets or more distant stars is effective on much longer timescales. If the latter processes dominate, planets will not be found close to their stars when they are young. ...

MEarth Array Confirms Youngest Transiting Exoplanet
Harvard Smithsonian Center for Astrophysics | 2016 June 20

Zodiacal Exoplanets in Time (ZEIT) III: A short-period planet orbiting
a pre-main-sequence star in the Upper Scorpius OB Association - Andrew W. Mann et al

• arXiv.org > astro-ph > arXiv:1604.06165 > 21 Apr 2016 (v1), 17 Jun 2016 (v2)

[neufer]

Zodiacal Exoplanets in Time (ZEIT) III: A short-period planet orbiting a pre-main-sequence star in the Upper Scorpius OB Association

<<We confirm and characterize a close-in, super-Neptune sized planet transiting K2-33, a late-type (M3) pre-main sequence (11 Myr-old) star in the Upper Scorpius subgroup of the Scorpius-Centaurus OB association. The host star has the kinematics of a member of the Upper Scorpius OB association, and its spectrum contains lithium absorption, an unambiguous sign of youth (<20 Myr) in late-type dwarfs.>>

• http://asterisk.apod.com/viewtopic.php? ... 30#p256130