Astronomers recently announced that the nearby star Proxima Centauri hosts an Earth-sized planet in its habitable zone. Proxima Centauri is a small, cool, red dwarf star only one-tenth as massive and one-thousandth as luminous as the Sun. However, new research shows that it is Sun-like in one surprising way: it has a regular cycle of starspots.
Like cosmic ballet dancers, the stars of the Pleiades cluster are spinning, but all at different speeds. By watching these stellar dancers, NASA’s Kepler space telescope has helped amass the most complete catalogue of rotation periods for stars in a cluster. This information can provide insight into where and how planets form around these stars, and how such stars evolve.
Astronomers searching for the galaxy’s youngest planets have found compelling evidence for one unlike any other, a newborn “hot Jupiter” whose outer layers are being torn away by the star it orbits every 11 hours. Dubbed “PTFO8-8695 b,” the suspected planet orbits a star about 1,100 light-years from Earth and is at most twice the mass of Jupiter.
Contradicting the long-standing idea that large Jupiter-mass planets take a minimum of 10 million years to form, astronomers have just announced the discovery of a giant planet in close orbit around a 2 million-year-old star that still retains a disc of circumstellar gas and dust. CI Tau b is at least eight times larger than Jupiter and 450 light-years from Earth.
Astrophysicists from Germany and America have for the first time measured the rotation periods of stars in a cluster nearly as old as the Sun. It turns out that these stars spin once in about twenty-six days — just like our Sun. This discovery significantly strengthens what is known as the solar-stellar connection, a fundamental principle that guides much of modern solar and stellar astrophysics.
Astronomers have used interferometry to create a time-lapse of the nearby star zeta Andromedae over one of its 18-day rotations that show starspots — sunspots outside our solar system. The pattern of spots on the star is very different from their typical arrangement on our Sun, challenging current theories of how stars’ magnetic fields influence their evolution.
Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, a blanketing atmosphere and a protective magnetic field. A new study of the young, Sun-like star Kappa Ceti shows that a magnetic field plays a key role in making a planet conducive to life.