This image captured by the Hubble Space Telescope features the dazzling Terzan 12, a dense assembly of stars bound together by gravity. This observation is part of a focused effort to study the globular clusters near the heart of our galaxy, including this one in the Sagittarius constellation. Deep within the Milky Way, clusters like Terzan 12 are often obscured by clouds of gas and dust. These clouds can obscure or change the starlight that we see from these clusters. Credit: ESA/Hubble & NASA, R. Cohen (Rutgers University)
The Hubble Space TelescopeThe Hubble Space Telescope (often referred to as Hubble or HST) is one of NASA's Great Observatories and was launched into low Earth orbit in 1990. It is one of the largest and most versatile space telescopes in use and features a 2.4-meter mirror and four main instruments that observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. It was named after astronomer Edwin Hubble.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>Hubble Space Telescope has captured a vivid image of the globular star cluster Terzan 12, illustrating how space dust can affect starlight.
This colorful image of the globular star cluster Terzan 12 is a spectacular example of how dust in space affects starlight coming from background objects.
A globular star cluster is a conglomeration of stars, arranged in a spheroidal shape. Stars in globular clusters are bound together by gravity, with a higher concentration of stars towards the center. The Milky WayThe Milky Way is the galaxy that contains our Solar System and is part of the Local Group of galaxies. It is a barred spiral galaxy that contains an estimated 100-400 billion stars and has a diameter between 150,000 and 200,000 light-years. The name "Milky Way" comes from the appearance of the galaxy from Earth as a faint band of light that stretches across the night sky, resembling spilled milk.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>Milky Way has about 150 ancient globular clusters at its outskirts. These clusters orbit around the galactic center, but far above and below the pancake-flat plane of our galaxy, like bees buzzing around a hive.
Dust’s Play on Starlight
The location of this globular cluster, deep in the Milky Way in the constellation Sagittarius, means that it is shrouded in gas and dust which absorb and alter the starlight emanating from Terzan 12. The cluster is about 15,000 light-years from Earth. This location leaves a lot of room for intervening interstellar dust particles between us and the cluster to scatter blue light, causing only the redder wavelengths to come through to Earth. The interstellar dust clouds are mottled so that different parts of the cluster look redder than other parts along our line of sight.
The brightest red stars in the photo are bloated, aging giants, many times larger than our Sun. They lie between Earth and the cluster. Only a few may actually be members of the cluster. The very brightest hot, blue stars are also along the line of sight and not inside the cluster, which only contains aging stars.
This composite image shows the location of the globular star cluster Terzan 12 as seen by the NASA/ESA Hubble Space Telescope.
Top: A view of a section of our Milky Way in the direction of the constellation Sagittarius. Dense clouds of dust are etched across a whitish background of stars. The object at upper right is the Rho Ophiuchi cloud complex.
Bottom left: Photo of a small portion of the Milky Way which is only one-degree across – twice the angular diameter of the full moon. The globular cluster is in the image center.
Bottom Right: A new Hubble Space Telescope image of the dense cluster Terzan 12. Intervening dust scatters starlight to create multiple reddish hues. The brightest red stars in the photo are bloated, aging giants, many times larger than our Sun. They lie between Earth and the cluster. Only a few may actually be members of the cluster. The very brightest hot, blue stars are also along the line of sight and not inside the cluster, which only contains aging stars. The cluster is about 15,000 light-years from Earth.
Credit: NASA, ESA, Stéphane Guisard, ESO, Digitized Sky Survey, ESA/Hubble, Roger Cohen (Rutgers University), Joseph DePasquale (STScI)
The Legacy of Terzan and Hubble’s Contribution
Terzan 12 is one of 11 globular clusters discovered by the Turkish-Armenian astronomer Agop Terzan approximately a half-century ago. With its sharp vision, Hubble has revolutionized the study of globular clusters ever since its launch in 1990. Hubble observations have shed light on the relation between age and composition in the Milky Way galaxy’s innermost globular clusters.
The Hubble Space Telescope is a project of international cooperation between NASAEstablished in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>NASA and ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
Source: SciTechDaily
