December 3, 2017

Mount Agung Volcano

Mount Agung Volcano

Mount Agung, Bali, Indonesia
November 26, 2017

Image Credit: Sonny Tumbelaka/AFP/Getty Images

Lenticular Galaxy NGC 5866

Lenticular Galaxy NGC 5866

NGC 5866 is an edge-on galaxy that is tilted to our line-of-sight. It is classified as an S0 lenticular, due to its flat stellar disk and large ellipsoidal bulge. NGC 5866 lies in the Northern constellation Draco, at a distance of 44 million light-years (13.5 Megaparsecs). It has a diameter of roughly 60,000 light-years (18,400 parsecs). This Hubble image of NGC 5866 is a combination of blue, green and red observations taken with the Hubble Telescope's Advanced Camera for Surveys in November 2005.

Image Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)
Explanation from: https://www.spacetelescope.org/images/opo0624b/

Exoplanet and debris disk orbiting a polluted white dwarf

Exoplanet and debris disk orbiting a polluted white dwarf

This artist's concept shows an exoplanet and debris disk orbiting a polluted white dwarf.

White dwarfs are dim, dense remnants of stars similar to the Sun that have exhausted their nuclear fuel and blown off their outer layers. By "pollution," astronomers mean heavy elements invading the photospheres -- the outer atmospheres -- of these stars.

The leading explanation is that exoplanets could push small rocky bodies toward the star, whose powerful gravity would pulverize them into dust. That dust, containing heavy elements from the torn-apart body, would then fall on the star.

Image Credit: NASA/JPL-Caltech
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA22084