astronomical pictures

Familiar stars in Orion and constellations across the sky now have official names. Over the past year, the International Astronomical Union, the only body officially tasked with naming stars, approved names already in common use for 227 of the brightest stars, including the most famous stars on the sky Sirius, Polaris, and Betelgeuse. Pictured, the constellation of Orion is shown with several of these now-official star names superposed. Spanning about 30 degrees, this breath-taking vista stretches across the well-known constellation from head to toe (left to right) and beyond. The common names for all three stars in Orion’s belt are also now official. At 1,500 light years away, the Great Orion Nebula is the closest large star forming region, here visible just right and below center. Also visible are famous nebulae including the Horsehead Nebula and the Witch Head Nebula. Of course, the Orion Nebula and bright stars are easy to see with the unaided eye, but dust clouds and emission from the extensive interstellar gas in this nebula-rich complex, are too faint and much harder to record. In the featured mosaic of broadband telescopic images, additional image data acquired with a narrow hydrogen alpha filter was used to bring out the pervasive tendrils of energized atomic hydrogen gas like in the arc of the giant Barnard’s Loop.

Credit: Rogelio Bernal Andreo

Time And Space

NASA hired Barbara S. Askins, a chemist at NASA’s Marshall Space Flight Center, Huntsville, Alabama, in 1975 to find a better way to develop astronomical and geological pictures. In 1978, the Association for Advancement of Inventions and Innovations named her the National Inventor of the Year for her invention of a process that restored detail to underexposed negatives that would otherwise be useless. In 1978, Barbara Askins patented a method of enhancing the pictures using radioactive materials. The process was so successful that its uses were expanded beyond NASA researchers to improvements in X-ray technology and in the restoration of old pictures.

This dazzling image shows the globular cluster Messier 69, or M 69 for short, as viewed through the NASA/ESA Hubble Space Telescope. Globular clusters are dense collections of old stars. In this picture, foreground stars look big and golden when set against the backdrop of the thousands of white, silvery stars that make up M 69.

Another aspect of M 69 lends itself to the bejewelled metaphor: As globular clusters go, M 69 is one of the most metal-rich on record. In astronomy, the term “metal” has a specialised meaning: it refers to any element heavier than the two most common elements in our Universe, hydrogen and helium. The nuclear fusion that powers stars created all of the metallic elements in nature, from the calcium in our bones to the carbon in diamonds. Successive generations of stars have built up the metallic abundances we see today.

Because the stars in globular clusters are ancient, their metallic abundances are much lower than more recently formed stars, such as the Sun. Studying the makeup of stars in globular clusters like M 69 has helped astronomers trace back the evolution of the cosmos.

M 69 is located 29 700 light-years away in the constellation Sagittarius (the Archer). The famed French comet hunter Charles Messier added M 69 to his catalogue in 1780. It is also known as NGC 6637.

The image is a combination of exposures taken in visible and near-infrared light by Hubble’s Advanced Camera for Surveys, and covers a field of view of approximately 3.4 by 3.4 arcminutes.

Object Names: M69

Image Type: Astronomical

Credit: ESA/Hubble & NASA

Time And Space