Delicate spiral arms encircle the bright nucleus of M63, the Sunflower galaxy, in this Hubble Space Telescope image. M63 is about the same size as our home galaxy, the Milky Way. The galaxy is in the west-northwest in early evening at this time of year, to the left of the handle of the Big Dipper. [NASA/ESA]
You are here
We live in a galaxy-eat-galaxy universe. Big galaxies frequently grab smaller ones, then make the stars and gas of the little ones their own. That may cause a dramatic change in the bigger galaxies.
A good example is M63, the Sunflower galaxy. It’s a stunningly beautiful spiral galaxy that resembles a sunflower. It’s about 27 million light-years away, and it’s about the same size as our own galaxy, the Milky Way.
One odd feature of the Sunflower is a streamer of stars that loops at least half-way around the galaxy. It’s about 10,000 light-years wide, and it contains hundreds of millions of stars — enough to make a small galaxy.
And in fact, that may be where the streamer came from. A couple of billion years ago, a dwarf galaxy may have passed close to the Sunflower. The gravity of the bigger galaxy grabbed the smaller one and pulled it apart, forming the streamer.
The encounter may have had some dramatic effects on the Sunflower as well. One edge of the galaxy’s disk is warped — a possible effect of the small galaxy’s gravity. Even more impressive, the encounter may have produced ripples in the Sunflower’s disk that created or enhanced its spiral structure. Those ripples may have triggered the birth of many new stars throughout the Sunflower — enhancing the beauty of this amazing galaxy.
The Sunflower is in the west-northwest at nightfall. It’s visible through a telescope, to the left of the handle of the Big Dipper.
Script by Damond Benningfield