Second Star to the Right …


tinkerbell_eso… and straight on ’til morning. Just follow Tinker Bell. This image from the ESO‘s Very Large Telescope shows a rare merger of three galaxies. The system, which bears a resemblance to Tinker Bell, is composed of two massive spiral galaxies and a third irregular galaxy.

The image is a multi-band composite of infrared data from the  VLT combined with archive images from Hubble. The VLT data allowed astronomers to not only see the two previously known galaxies, but to identify a third, an irregular, massive galaxy that seems to form stars at a frantic rate.

Image Credit: ESO

R Sculptoris


This image, which was taken by the Very Large Telescope at the European Southern Observatory, shows an extremely small section of the sky: approximately 20×20 milliarcseconds. For comparison, Jupiter as seen from Earth has an angular size of roughly 40 arcseconds. The ghostly image is of a distant, pulsating red giant star known as R Sculptoris, which is 1200 light-years away in the constellation of Sculptor. It’s a carbon-rich asymptotic giant branch star that is nearing the end of its life. As the end comes, low- and intermediate-mass stars cool off, create extended atmospheres, and lose a lot of their mass—before becoming spectacular planetary nebulae.

One odd feature of R Sculptoris is its dominant bright spot which seems to be two or three times brighter than the rest of the star. Astronomers speculate that R Sculptoris is surrounded by giant “clumps” of stellar dust that are peeling away from the shedding star. This bright spot is probably a region around the star with less dust, allowing more light to escape.

Image Credit: ESO

Uranus and Four of Its Satellites


This infrared image of the planet Uranus was captured by the European Southern Observatory’s Very Large Telescope during the planet’s 2008 equinox. Every 42 years, the ring (and satellites) plane of Uranus line up with the Sun causing them to appear on edge from Earth’s point of view. A one minute exposure time was used, the maximum allowable to prevent the moving satellites from appearing as streaks. The IR filter used matches the absorption bands of the methane in the atmosphere of Uranus, making the relatively bright planet (almost) completely disappear. That permits the otherwise invisible rings and small satellites of Uranus to be detected instead of being lost in the glare of the planet. The bright spots on each side of Uranus are Miranda (~470 km diameter) and Ariel (~1100 km diameter). Two much smaller satellites can be seen just above the ring plane,to the left of the planet. Puck (~150 km diameter) is closer to the Planet than Portia (~100 km diameter).

Image Credit: ESO