NASA Astronomy Picture of the Day 14 April 2023: Fascinating Hamburger Galaxy

Although most galaxies have elliptical shapes, a few have unusual shapes like toothpicks or rings. One of the most spectacular looking galaxies are the Spiral galaxies, which have winding spiral arms that make them look a little like massive pinwheels. These disks of stars, gas, and dust have bright bulges in their centers made up primarily of older and dimmer stars. Their whirled arms are typically full of gas and dust, which helps give rise to the bright, younger stars visible throughout their length.

Today’s NASA Astronomy Picture of the Day is a fascinating snapshot of NGC 3628, also known as the Hamburger Galaxy. It is a spiral galaxy located about 35 million light-years away towards the constellation of Leo and spans about 100,000 light-years. According to NASA, NGC 3628 shares its neighborhood in the local Universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet.

The picture was captured by astrophotographers Mike Selby and Mark Hanson.

NASA's description of the picture

Explanation: Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby (below), likely a satellite of NGC 3628, and a very faint but extensive tidal tail. The drawn out tail stretches for about 300,000 light-years, even beyond the left edge of the frame.

NGC 3628 shares its neighborhood in the local universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for creating the tidal tail, as well as the extended flare and warp of this spiral's disk. The tantalizing island universe itself is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo.