SoylentNews

takyon [soylentnews.org] writes:

Baby Exoplanet Weighed for First Time [space.com]

Astronomers have measured the mass of a very young alien planet for the first time, thanks to more than two decades' worth of data collected by two of the European Space Agency's star-mapping satellites.

The exoplanet — known as Beta Pictoris b — is a gas giant like Jupiter, but scientists estimate it is nine to 13 times more massive than our solar system's biggest planet. Discovered in 2008, this exoplanet orbits the star Beta Pictoris [space.com], the second brightest star in the constellation of Pictor.

Because this star is still very young, it demonstrates how planets form and evolve. However, because the star is still forming and pulsing with activity, it's challenging for astronomers to accurately measure the star's radial velocity (speed as the star moves toward and away from Earth as its planet orbits). This is a method commonly used to estimate the mass of exoplanets.

Instead, the weight of Beta Pictoris b was calculated based on the position and motion of its host star in the sky over a long period of time, according to a statement from ESA.

Beta Pictoris [wikipedia.org].

Also at ESA [esa.int].

The mass of the young planet Beta Pictoris b through the astrometric motion of its host star [nature.com] (DOI: 10.1038/s41550-018-0561-6) (DX [doi.org])

Original Submission