Free Astronomy Magazine September-October 2023

11 SEPTEMBER-OCTOBER 2023 At the relatively young age of about 1 million years, HR 5999 and HR 6000 are the oldest of the stars in the Lupus 3 region. These stars are pre-main-sequence stars, mean- ing that despite their brightness, they are not yet powered by nuclear fusion, like our Sun. They are in- stead powered by gravity, which compresses and heats up the inter- nal matter. These sibling stars have blown away nearby gas and dust, illuminating the remnants and creating the Bernes 149 reflection nebula. When the true nature of this nebula was first discovered, astronomers hoped that it and similar regions would be useful in finding areas of recent or active star formation. This hunch was proven correct and Lupus 3 has since provided many insights into the early stages of star formation. Lupus 3 is one of at least nine clouds within the massive Lupus cloud complex. Lupus 3 itself stretches across an area of the sky equivalent to about 24 Moon-diameters as seen from Earth. With a whopping 2.2-degree field of view, DECcam can capture massive ob- jects like Lupus 3 in a single image. The pairing of DE- Cam’s wide-field ca- pabilities and the light-collecting ca- pabilities of the Víc- tor M. Blanco 4-me- ter Telescope’s wide mirror produces crisp, high resolu- tion images. T he two young, low-mass protostars HR 5999 and HR 6000 illu- minate nearby dust, creating the reflection nebula Bernes 149. These stars grew out of the dusty dark cloud of Lupus 3, part of a larger complex of as many as nine dark clouds. [CTIO/NOIRLab/DOE/ NSF/AURA/T.A. Rector (University of Alaska Anchorage/NSF’s NOIR- Lab). Image Processing: D. de Martin & M. Zamani (NSF’s NOIRLab)] T his video shows the massive, star-forming interstellar cloud Lupus 3. The dazzling central re- gion of this sprawling cloud re- veals a pair of infant stars bursting from their natal cocoons of dust and gas to illuminate the reflection nebula known as Bernes 149. [CTIO/NOIRLab/DOE/ NSF/AURA/ T.A. Rector (Univ. of Alaska Anchorage/NSF’s NOIR- Lab) DSS 2/N. Bartmann/D. de Martin, M. Zamani & D. de Martin. Music: Stellardrone − Airglow] !