A Pair of Lonely Dwarfs

Luhman 16AB is a double star system composed of two brown dwarfs. It’s only about six light-years away, and is the third closest stellar system to Earth—after the triple star system Alpha Centauri and Barnard’s Star. Because the brown dwarfs are so dim, Luhman 16AB was only discovered in 2013.

This series of dots with varying spacings between them in the image above shows the slow waltz of the two brown dwarfs. It’s a composite of 12 images made over the course of three years by the Hubble Space Telescope. Using high-precision astrometry, a team of astronomers tracked the two components of the system as they moved both across the sky and around each other.

The brown dwarfs, Luhman 16A and Luhman 16B, orbit each other at a distance of only about 500,000,000 km, roughly three times the distance between the Earth and the Sun. Observations of the system require high resolution. The astronomers using Hubble to study Luhman 16AB were not only interested in the waltz of the two starss as they orbited each other but also were also searching for a third, invisible partner. Earlier ground-based observation suggested the presence of an exoplanet in the system, but the Hubble data showed that the two dwarfs are indeed dancing alone, unperturbed by a massive planetary companion.

Image Credit: NASA / ESA

The Center of the Lagoon Nebula

The Lagoon Nebula, aka M8, is about 5,000 light years away in the constellation of Sagittarius. The center of the Lagoon Nebula is a maelstrom of star formation. The long funnel-shaped clouds on the lower left are roughly half a light-year long and have been formed by extreme stellar winds and intense energetic starlight. An extremely bright nearby star, Hershel 36, lights the area. Dust hides or reddens other hot young stars from our point of view. As energy from these stars flows into the cool dust and gas, the large temperature differences between adjoining regions can create generating shearing winds which may cause funnels to form.

Image Credit: NASA / ESA