Spiral galaxy ESO 137-001


Spiral galaxy ESO 137-001 hurtles through massive galaxy cluster Abell 3627 some 220 million light years away. The distant galaxy is seen in this colorful Hubble/Chandra composite image through a foreground of the Milky Way’s stars toward the southern constellation Triangulum Australe.

Spiral galaxy ESO 137-001

As the spiral speeds along at nearly 7 million kilometers per hour, its gas and dust are stripped away when ram pressure with the cluster’s own tenuous intracluster medium overcomes the galaxy’s gravity.

Evident in Hubble’s near visible light data, bright star clusters have formed in the stripped material along the short, trailing blue streaks. Chandra’s X-ray data shows off the enormous extent of the heated, stripped gas as diffuse, darker blue trails stretching over 400,000 light-years toward the bottom right.

The significant loss of dust and gas will make new star formation difficult for this galaxy. A yellowish elliptical galaxy, lacking in star forming dust and gas, is just to the right of ESO 137-001 in the frame.

Image Credit: NASA, ESA, CXC

Symbiotic R Aquarii – two orbiting stars


You can see it change in brightness with just binoculars over the course of a year. Variable star R Aquarii is actually an interacting binary star system, two stars that seem to have a close, symbiotic relationship.

About 710 light years away, this intriguing system consists of a red giant star and dense white dwarf star in mutual orbit around their common center of mass.

The binary system’s visible light is dominated by the red giant, itself a Mira-type long period variable star. But material in the giant star’s extended envelope is pulled by gravity onto the surface of the smaller, denser white dwarf, eventually triggering a thermonuclear explosion and blasting material into space.

The featured image from the Hubble Space Telescope shows the still-expanding ring of debris which spans less than a light year and originated from a blast that would have been seen in the early 1770s.

Symbiotic R Aquarii - two orbiting stars

The evolution of less understood energetic events producing high energy emission in the R Aquarii system has been monitored since 2000 using Chandra X-ray Observatory data.

Image Credit: Hubble, NASA, ESA; Processing & License: Judy Schmidt

M86 in the Central Virgo Cluster


Is there a bridge of gas connecting these two great galaxies? Quite possibly, but it is hard to be sure. M86 on the upper left is a giant elliptical galaxy near the center of the nearby Virgo Cluster of galaxies.

Our Milky Way Galaxy is falling toward the Virgo Cluster, located about 50 million light years away. To the lower right of M86 is unusual spiral galaxy NGC 4438, which, together with angular neighbor NGC 4435, are known as the Eyes Galaxies (also Arp 120).

Featured here is one of the deeper images yet taken of the region, indicating that red-glowing gas surrounds M86 and seemingly connects it to NGC 4438. The image spans about the size of the full moon. It is also known, however, that cirrus gas in our own Galaxy is superposed in front of the Virgo cluster, and observations of the low speed of this gas seem more consistent with this Milky Way origin hypothesis.

M86 in the Central Virgo Cluster

M86 in the Central Virgo Cluster


A definitive answer may come from future research, which may also resolve how the extended blue arms of NGC 4435 were created.

Image Credit & Copyright: Mark Hanson, Stan Watson Obs.