Tag Archives: variability

First L Dwarf in the Kepler Field

An image of WISE 1906+4011 from the Kepler Observatory; the green mask marks the location of this faint source.

The Kepler Observatory is uncovering numerous planets in close orbits around distant stars.  Now it has a brown dwarf under its belt.  A search for nearby cool dwarfs by University of Delaware collaborator John Gizis uncovered the first L dwarf in Kepler, a source that may teach us much about clouds in cool brown dwarfs. Continue reading

Discovery of a Wacko Star

Jets, disks and accretion in nearby low mass star

U. Hawaii Graduate student Dagny Looper reports the discovery of a young, low-mass nearby star that is both unusually active and highly variable. The star, TWA 30, is a member of the TW Hydrae Association, roughly two dozen ~8 million year-old stars located about 50 pc away. TWA 30 is the newest member of this group, and one of the most intriguing. Its optical spectrum shows classical and forbidden emission lines, indicating that it is both accreting material and emitting high-speed jets of gas. The star’s near-infrared color also varies dramatically on week-long timescales, evidence that it periodically hides behind a nearly edge-on circumstellar disk. This makes TWA 30 one of the nearest T Tauri stars to the Sun.

The paper was published in the Astrophysical Journal.

May 2010