Free Astronomy Magazine May-June 2025

29 MAY-JUNE 2025 N GC 2040 is a young open cluster of stars within the Large Magellanic Cloud, a satellite galaxy of the Milky Way, located about 160,000 light-years from Earth. It is a type of star cluster known as an OB association because it con- tains more than a dozen stars of the O and B spectral types. These stars lead short lives of only a few million years, during which they burn very hot before exploding as supernovae. The energy released by the explo- sions of these massive stars feeds the formation of NGC 2040’s structure, while the expelled material seeds the growth of the next generation of stars. The veiled nebula’s delicate structure is revealed in this image captured with the Gemini South telescope, one half of the International Gemini Observa- tory, funded in part by the U.S. National Science Foundation and operated by NSF NOIRLab. The 8-meter optical/infrared tel- escope is perfectly suited to cap- turing both the bright stars and the diffuse glow of the cluster. NGC 2040 contains mostly hy- drogen and oxygen atoms. As these atoms are excited by the ultraviolet radiation from nearby massive stars, they emit light. This emitted light spans a range of wavelengths from the ultraviolet, through the visible, and into the infrared. Special fil- ters on Gemini South then allow specific wavelengths, or colors, of this emitted light to pass through, like the deep red and orange of glowing hydrogen and the light blue of glowing oxygen. The bright white repre- sents areas where there is an abundance of both. NGC 2040 is so named because it is part of the New General Cata- logue of deep sky objects, first compiled by John Dryer in 1888. More recent observations have revealed that it is part of a mas- sive structure of interstellar gas known as LH 88, which is one of the largest active star-forming regions in the Large Magellanic Cloud. Over the next million years thousands of new stars will be born in the region. Most of the stars in the Milky Way, including the Sun, likely formed within open clusters sim- ilar to NGC 2040. When the O and B stars end their lives as su- pernovae they will enrich the cluster with elements such as carbon, oxygen, and iron. To- gether with the bountiful hy- drogen of the cluster, these elements provide the necessary ingredients for the formation of new stars, planets, and perhaps even life. The bright stars seen in the image are widely separated, but their motions through space are similar, indicating that they have a common origin. The layered nebulous structures in LH 88 are the remnants of stars that have already died. The delicate leaves of the rose were formed by both the shockwaves from super- novae and the stellar winds of the O and B stars. Taken as a whole, the rose of LH 88 tells a story of death and re- birth, where the dust of dead stars becomes the seeds of new stars and planetary systems. And like a rose the beauty of LH 88 is fleeting. Within a few million years — a brief moment of cos- mic time — the gas and dust will be either gathered into young stars or cast off into interstellar space. The stars formed within the cluster will have moved on to their own journeys through their galaxy. ! D isplaying wispy layers of red, orange and yellow, the nebula encasing NGC 2040 re- sembles a vibrant rose in this image captured by the Gemini South telescope. This nebulous flower showcases the dramatic story of stellar life, death and rebirth. [International Gemini Observatory/NOIRLab/NSF/AURA. Image Pro- cessing: J. Miller & M. Rodriguez (Interna- tional Gemini Observatory/NSF NOIRLab), T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), M. Zamani (NSF NOIRLab)]