NASA Image Compiles the Entire Sharpless Catalog of 313 Nebulas

A newly compiled astronomical image brings together the entire Sharpless Catalog of H II regions, encompassing all 313 cataloged nebulas in a single composite view, according to NASA's Astronomy Picture of the Day feature.

The Sharpless Catalog, first published in the mid-20th century, lists hydrogen-rich emission nebulas, known as H II regions, found throughout the night sky. These regions mark areas where hydrogen gas glows due to the intense ultraviolet radiation from nearby young, hot stars, often signaling active star formation.

Compiling an image that captures all 313 objects in the catalog required combining data and imaging techniques capable of covering a vast swath of the sky in a single composite, giving viewers the chance to zoom in and explore individual nebulas within the larger mosaic.

H II regions are of particular interest to astronomers because they offer insight into the life cycles of stars, including the conditions under which new stars form from clouds of gas and dust. Studying them collectively, as this catalog compilation allows, offers a broader picture of star-forming activity across the observable galaxy.

The image was featured as NASA's Astronomy Picture of the Day, a long-running feature that highlights notable images and explanations related to astronomy and space science.