Pandora’s Cluster

abell-2744This image of Pandora’s Cluster, a galaxy cluster also know as Abell 2744, was taken by the Spitzer Space Telescope in infrared light. The gravity of this galaxy cluster is strong enough to act as a lens magnifying the images of more distant background galaxies. That is called gravitational lensing. The fuzzy blobs in this picture are the massive galaxies at the core of the cluster.

Image Credit: NASA

NGC 2440

Hubble reveals NGC 2440This Hubble Space Telescope image shows the colorful end of a star like the Sun. This star is casting off its outer layers of gas, which formed a cocoon around the star’s remaining core. Ultraviolet light from the dying star makes the material glow. The burned-out star, a white dwarf, is the white dot in the center. Our Sun will eventually burn out and surround itself with stellar debris, but that’s not expected for another 5 billion years or so.

The galaxy is filled with these stellar relics called planetary nebulae. (They have nothing to do with planets. 18th- and 19th-century astronomers used that name because through small telescopes the nebulae resembled the disks of the planets Uranus and Neptune.) This planetary nebula in this image is named NGC 2440. The white dwarf at the center of NGC 2440 is one of the hottest known, with a surface temperature of more than 200,000°C. The nebula’s chaotic structure suggests that the star shed its mass in multiple stages. During each outburst, the star blew off material in a different direction, resulting in the two bowtie-shaped lobes.

The material expelled by the star glows with different colors depending on its composition, its density and how close it is to the hot central star. Blue samples helium; blue-green oxygen, and red nitrogen and hydrogen.

Image Credit: NASA / ESA

Probing Deeper Into the Hubble Deep Field

This video sequence combines a background picture taken by the Hubble Space Telescope (blue/green) with a new very deep view of this field using the European Southern Observatory’s ALMA instruments (orange, marked with circles). All the objects that ALMA sees appear to be massive star-forming galaxies.

Video Credit: ESO
Image Credits: ESA/NASA/ESO

The Helix Nebula in Infrared


When viewed in IR by the Spitzer Space Telescope, the Helix Nebula shows a glow that suggests that the central star is surrounded by an unusual cloud of dust. One theory is that the cloud is made up of debris from collisions between the material ejected by the star when it exploded and the comets and other bodies in that star’s equivalent of the Solar System’s Kuiper Belt.

Image Credit: NASA