In this new image from NASA’s Hubble Space Telescope, a spiral galaxy glittering with star clusters takes center stage. NGC 3137 is located 53 million light-years away in the constellation Antlia (the Air Pump). As a nearby spiral galaxy, this target offers astronomers an excellent opportunity to study the cycle of stellar birth and death, while also providing researchers a glimpse of a galactic system similar to our own.
NGC 3137 is of particular interest to astronomers because it travels through space with a group of galaxies thought to be similar to the Local Group, the galaxy group that contains our Milky Way. Like the Local Group, the NGC 3175 group contains two large spiral galaxies: NGC 3137 and NGC 3175, which Hubble has also observed. In the Local Group, the largest members are the Milky Way and Andromeda, another spiral galaxy. Both groups also contain numerous smaller dwarf galaxies, though researchers have found more than 500 dwarf galaxy candidates within the NGC 3175 group. By studying this nearby galaxy group, astronomers can learn about the dynamics of our own galactic home.
NGC 3137 is revealed in remarkable detail by Hubble. This image, crafted from observations in six different color bands, highlights several facets of this beautiful spiral. The galaxy’s center — encircled by a network of fine, dusty clouds — hosts a black hole estimated to be 60 million times more massive than the Sun. NGC 3137 is highly inclined from our point of view, offering a unique perspective on its loose, feathery spiral structure. A couple of photobombing Milky Way stars and a smattering of far more distant background galaxies complete the image.
While each of these features is striking, it is the galaxy’s brilliant star clusters that steal the show. The galaxy is peppered with dense clusters of bright blue stars and glowing red gas clouds, signaling the presence of hot, young stars still encased in their birth nebulae.
Unsurprisingly, these star clusters are exactly what has drawn Hubble’s keen eye. Researchers are using Hubble to carry out an observing program (Program #17502; Principal Investigator: D. Thilker) focusing on star clusters in 55 nearby galaxies. The data collected will help astronomers identify star clusters and the glowing nebulae that surround them, providing a way to measure the ages of stars in galaxies like NGC 3137. These observations offer an in-depth view of stellar life in spiral galaxies, from young stars still in the process of forming to ancient stellar populations that grew up in the early years of their galactic hosts.
The PHANGS-HST program (Physics at High Angular Resolution in Nearby Galaxies), for which these observations were taken, is part of a larger effort combining Hubble data with observations from the NASA/ESA/CSA James Webb Space Telescope and the Atacama Large Millimeter/submillimeter Array (ALMA). Together, Hubble’s powerful optical and ultraviolet capabilities, Webb’s sensitive infrared eyes, and ALMA’s broad network of radio dishes provide an unmatched view of star formation in the local universe.
