This week’s Hubble image shows the beautiful rosy glow of a dusty spiral galaxy where stars are being born. The galaxy is called NGC 972, and it was discovered in 1784 by William Herschel. It is located in the constellation of Aries, 71 million light-years away from Earth.
Cosmic dust is the particulate matter that floats around in space, in this case called interstellar dust as it exists between stars. Other types of cosmic dust are dust rings around planets, called circumplanetary dust, as well as interstellar dust and interplanetary dust. In our Solar System, it is cosmic dust that is responsible for the “false dawn” phenomenon, in which faint white light is seen over the horizon before the sun rises.
Although cosmic dust was once considered a nuisance to astronomers because it obscured their view of stars, planets, and other bodies, more recently the dust itself has become an important object of study. Dust is made up of a variety of compounds, including complex organic compounds created by the evolution of stars, so studying it can give clues to the lifespan of celestial bodies.
In this case, the cosmic dust in NGC 972 is an important factor in the development of stars in the region. The bright glowing spots in the Hubble image are areas where stars are being born, and the dark swirls are areas of dust which blocks the light from the stars. The glow of orange and pink around the stars is illuminated hydrogen, which glows when the gas is exposed to intense light from the forming stars.
“We look for these telltale signs of star formation when we study galaxies throughout the cosmos, as star formation rates, locations, and histories offer critical clues as to how these colossal collections of gas and dust have evolved over time,” the Hubble astronomers said in a statement.
“New generations of stars contribute to — and are also, in turn, influenced by — the broader forces and factors that mold galaxies throughout the Universe, such as gravity, radiation, matter, and dark matter.”
