Brushstrokes across the sky

Lynn Savage, lynn.savage@laurin.com

In 1745, Swiss astronomer Jean-Philippe Loys de Chéseaux discovered a new object in the sky that somewhat resembled the Greek letter “omega.” Or maybe it looked like a swan of sorts. In actuality, it’s a nursery for a multitude of newly born stars.

Now known as the Omega Nebula, the 17th member of Charles Messier’s famed catalog has also been called the Swan, the Lobster and the Horseshoe and is a favorite object to view among professional and amateur stargazers alike. Set your sight toward Sagittarius, and look for a region of gas and dust about 15 light-years across. It should appear as a spectral light framed against the background provided by the Milky Way itself. In very good observing conditions, the approximately 6.0-magnitude nebula can even be seen with the naked eye.

Photo courtesy of the European Southern Observatory.

The popularity of the Omega Nebula is largely due to its proximity – only about 5500 light-years away – and to its prolific ability to create new stars. It is one of the youngest stellar nurseries, and it continues to birth new suns even now. The space-borne winds and brilliantly burning infant stars form streaks of glowing gases like paint strokes against a dark canvas.

In a newly released image, shown here, the central region of the nebula is displayed with more detail than ever seen before. The watercolorlike palette indicates billows of hydrogen, oxygen, nitrogen, sulfur and other gases glowing under the ultraviolet light being emitted by the bright young stars in the region. The hydrogen, in particular, is responsible for the red to dusty pink hues in the formation.

The image was acquired by the European Southern Observatory Multi-Mode Instrument (EMMI) on the New Technology Telescope located at the La Silla Observatory in Chile. The EMMI is a collection of detectors that aid imaging in the 300- to 1000-nm range with the 3.58-m telescope.