Credit: NOIRLab/NSF/AURA/P. Horálek (Institute of Physics in Opava)

This Image of the Week is of the Large Magellanic Cloud (LMC), a dwarf galaxy that appears cloud-like in the Southern Hemisphere. This image was captured by photographer Petr Horálek, a NOIRLab Audiovisual Ambassador, using a wide-aperture telephoto lens on a commercial camera. Petr photographed the LMC over about four hours during three nights on Cerro Pachón in Chile, home of Gemini South, one half of the International Gemini Observatory, operated by NSF NOIRLab.  The LMC is one of the 60+ satellite galaxies orbiting the Milky Way. Satellite galaxies are usually smaller than their host galaxy. Case in point, the LMC consists of around 20 billion stars, while our Milky Way galaxy holds between 100–400 billion stars. The LMC is also considered an irregular galaxy because of its indistinct shape. Its central bright bar is geometrically off-center, which has led astronomers to believe this galaxy was once a barred spiral galaxy, like the Milky Way. The LMC’s once well-defined spiral arms have been warped by the pull of gravity, likely from the Milky Way and the Small Magellanic Cloud (SMC), another dwarf galaxy visible near the LMC. Like most irregular galaxies, the LMC is a prime site for star formation. It even hosts the most active star-forming region among our nearby galaxies, the nebula Doradus 30 (Tarantula Nebula). The LMC also has an extra advantage: the more massive LMC has been observed to “steal” gas and stars from the neighboring SMC. As the stellar materials are pulled from the SMC, they collide with the LMC’s own materials and form an intergalactic gaseous bridge between the clouds. These collisions pressurize and concentrate the gas, making star formation much more likely in the LMC and the bridge itself.

Provider: NOIRLab

Image Source: https://noirlab.edu/public/images/iotw2547a/

Curator: NSF's NOIRLab, Tucson, AZ, USA

Image Use Policy: Creative Commons Attribution 4.0 International License