Radiant Stars at the Heart of a Cosmic Rose

October 1, 2024

Dark Energy Camera captures most detailed image of the resplendent Rosette Nebula and the star cluster fueling its glow

Radiant Stars at the Heart of a Cosmic Rose

Cradled within the fiery petals of the Rosette Nebula is NGC 2244, the young star cluster which it nurtured. The cluster’s stars light up the nebula in vibrant hues of red, gold and purple, and opaque towers of dust rise from the billowing clouds around its excavated core. This image, captured by the 570-megapixel Dark Energy Camera, is being released in celebration of NOIRLab’s fifth anniversary.

Around 5000 light-years away, the Rosette Nebula appears to be blooming right out the interstellar medium. Every detail of this cosmic flower, from its glowing central cavity to its shadowy filaments and globulettes, is captured in this image by the 570-megapixel Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF NOIRLab.

Located in the constellation Monoceros (the Unicorn), the Rosette Nebula spans 1.3 degrees of sky, roughly the width of an index finger held out at arm’s length. For comparison, the well-known Orion Nebula, located in the constellation Orion just below the hunter’s belt, spans one degree of sky. Although the Rosette Nebula has a diameter of 130 light-years — more than five times as large as the Orion Nebula — their apparent sizes are similar because the former is four times as distant.

As prominent as the nebula’s ‘petals’ is the conspicuous absence of gas at its center. The culprits responsible for excavating this hollow core are the most massive stars of NGC 2244 — the open star cluster nurtured by the nebula. This cluster was born around two million years ago after the nebula’s gasses coalesced into clumps brought together by their mutual gravity. Eventually, some clumps grew to be massive stars that produce stellar winds powerful enough to bore a hole in the nebula’s heart.

NGC 2244’s massive stars also emit ultraviolet radiation, which ionizes the surrounding hydrogen gas and lights up the nebula in an array of brilliant colors. The billowing red clouds are regions of H-alpha emission, resulting from highly energized hydrogen atoms emitting red light. Along the walls of the central cavity, closer to the massive central stars, the radiation is energetic enough to ionize a heavier atom like oxygen, which glows in shades of gold and yellow. Finally, along the edges of the flower’s petals are wispy tendrils of deep pink glowing from the light emitted by ionized silicon.

The Rosette Nebula’s bright and glowing features are certainly striking; but its dark and shadowy features also command attention. Around the nebula’s excavated nucleus is a string of dark clouds dubbed ‘elephant trunks,’ so-named because of their trunk-like pillars. These structures are opaque because they contain obscuring dust, and they line the border between the hot shell of ionized hydrogen and the surrounding environment of cooler hydrogen. As the shell expands outwards it encounters cold and clumpy gas that resists its push. This creates the long and extended trunks whose lengths point like fingers towards the central cluster.

One of these dark features is the Wrench Trunk, its claw-like head seen towards the upper right of the central cluster. Unlike the prototypical Pillars of Creation trunks which stand like straight columns, the Wrench’s ‘handle’ has an unusual spiral shape which traces the magnetic field of the nebula.

Less obvious but equally interesting are the dark globulettes. Sometimes round and sometimes teardrop-shaped, these diminutive blobs of dust are smaller than the better known globules at only a few times more massive than Jupiter. A string of them can be seen near the Wrench Trunk, but hundreds more dot the entire Rosette Nebula. These globulettes may host brown dwarfs and planets within them.

Like all roses, the Rosette Nebula will not last forever, for the same stars it birthed will also bring about its death. In roughly 10 million years the radiation from the hot, young stars of the NGC 2244 cluster will have dissipated the nebula. By then the rosette will no longer be, and its massive stars will be left without their parent cloud.

This huge 377-megapixel image is being released in celebration of NOIRLab’s fifth anniversary. On 1 October 2019 NOIRLab’s five programs — Cerro Tololo Inter-American Observatory, the Community Science and Data Center, the International Gemini Observatory, Kitt Peak National Observatory and Vera C. Rubin Observatory — were brought together under one organization. In the years since, NOIRLab’s world-class telescopes have contributed to many discoveries and countless press releases, and produced an impressive collection of stunning astronomical images showcasing our diverse and colorful Universe.

More Information

NSF NOIRLab (U.S. National Science Foundation National Optical-Infrared Astronomy Research Laboratory), the U.S. center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (operated in cooperation with the Department of Energy’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.