Interacting galaxies
Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope as part of a dark energy survey. It shows two galaxies very close together, their perpheries only about 40,000 light years apart, with the larger galaxy about the size of the Milky Way.
For comparison, the Large Magellanic Cloud (LMC) is about 167,000 light years from the Milky Way, more than four times farther that this satellite galaxy. Yet the satellite galaxy here appears much larger than the LMC, having a central core that the LMC lacks. From the caption:
Given this, coupled with the fact that NGC 5996 is roughly comparable in size to the Milky Way, it is not surprising that NGC 5996 and NGC 5994 — apparently separated by only 40 thousand light-years or so — are interacting with one another. In fact, the interaction might be what has caused the spiral shape of NGC 5996 to distort and apparently be drawn in the direction of NGC 5994. It also prompted the formation of the very long and faint tail of stars and gas curving away from NGC 5996, up to the top right of the image. This ‘tidal tail’ is a common phenomenon that appears when galaxies get in close together, as can be seen in several Hubble images.
In this single picture we are witnessing evidence of a process that has been going on for likely many millions of years.
Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope as part of a dark energy survey. It shows two galaxies very close together, their perpheries only about 40,000 light years apart, with the larger galaxy about the size of the Milky Way.
For comparison, the Large Magellanic Cloud (LMC) is about 167,000 light years from the Milky Way, more than four times farther that this satellite galaxy. Yet the satellite galaxy here appears much larger than the LMC, having a central core that the LMC lacks. From the caption:
Given this, coupled with the fact that NGC 5996 is roughly comparable in size to the Milky Way, it is not surprising that NGC 5996 and NGC 5994 — apparently separated by only 40 thousand light-years or so — are interacting with one another. In fact, the interaction might be what has caused the spiral shape of NGC 5996 to distort and apparently be drawn in the direction of NGC 5994. It also prompted the formation of the very long and faint tail of stars and gas curving away from NGC 5996, up to the top right of the image. This ‘tidal tail’ is a common phenomenon that appears when galaxies get in close together, as can be seen in several Hubble images.
In this single picture we are witnessing evidence of a process that has been going on for likely many millions of years.