The NASA/ESA (European Space Agency) Hubble Space Telescope has captured breathtaking images of the cosmos since it was commissioned in 1990. Recently, Hubble imaged two ‘overlapping spiral galaxies’ located more than a billion light-years from Earth, and a ‘glittering gathering’ of stars. The latter is a globular cluster. Hubble has also captured a ‘galactic marvel’ in Aries Constellation. Astronomers recently observed in a Hubble image of that a star in the Lacerta constellation outshines the galaxy. They also found that the star is much closer than the distant galaxy.
Overlapping Spiral Galaxies
The galaxies captured by Hubble are SDSS J115331 and LEDA 2073461. In the Hubble image, the two spiral galaxies appear to collide. However, the alignment of the two galaxies is probably just by chance, according to NASA. In reality, the two spiral galaxies are not interacting.
‘Glittering Gathering’ Of Stars
The ‘glittering gathering’ of stars is the globular cluster NGC 6558. Hubble’s Advanced Camera for Surveys recently captured the globular cluster, which lies about 23,000 light-years away in the constellation Sagittarius. The globular cluster is closer to the centre of the Milky Way galaxy than Earth is.
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What Are Globular Clusters?
Globular clusters are tightly bound collections of tens of thousands to millions of stars, and are found in a wide range of galaxies. The globular cluster imaged by Hubble is packed with stars in a rich variety of hues.
Some of the brightest inhabitants of NGC 6558 show prominent diffraction spikes. These are imaging artefacts, and the result of starlight interacting with the support system of Hubble’s secondary mirror.
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According to NASA, globular clusters are interesting “natural laboratories” where astronomers can test their theories. The stars in a globular cluster are formed at approximately the same time with similar initial compositions. Therefore, these stars provide unique insights into how different stars evolve under similar conditions. Hubble’s image comes from a set of observations investigating globular clusters in the inner Milky Way galaxy.
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Astronomers Observe Lacerta’s Star Outshines A Galaxy
The Hubble Space Telescope captured a little-studied star in the Lizard Constellation, called Lacerta, in 2017. Astronomers recently observed that Lacerta’s star outshines a galaxy in the constellation. Also, the star is much closer than the much more distant galaxy.
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These stars are called “foreground stars”. Astronomers studying distant objects are often not very happy about foreground stars because their bright light contaminates the faint light from the more distant and interesting objects they actually want to study.
Galactic Marvel In Aries Constellation
The Hubble Space Telescope recently captured an image of NGC 1156, a dwarf irregular galaxy in the Aries Constellation. NGC 1156 is unlike many of the galaxies familiar to Hubble. The galaxy is packed with thousands of bright stars. Ideally, the shape of the galaxy should have been spiral, but NGC 1156 lacks the characteristic ‘winding’ structure. The shining red blossoms in the galactic marvel stand out, twisted by clouds of dust. These are the regions of intense star formation, according to NASA.
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NGC 1156 radiates a diffuse glow, and has a core of older, redder stars. The galactic marvel is located 25 million light-years from Earth, and has a variety of different features that are of interest to astronomers. The dwarf irregular galaxy is also classified as isolated. This means no other galaxies are nearby enough to influence its odd shape and continuing star formation.
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According to NASA, the extreme energy of freshly formed young stars gives colour to the galaxy, against the red glow of ionised hydrogen gas. The centre of NGC 1156 is densely packed with older generations of stars.
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Hubble has captured the galactic marvel in the past. The new Hubble image features data from a galactic gap-filling programme titled “Every Known Nearby Galaxy”.
According to astronomers, Hubble has observed only three quarters of the galaxies within just over 30 million light-years of Earth in sufficient detail to study the makeup of the stars within them. Astronomers proposed that in between larger projects, Hubble could capture images of the remaining quarter, including NGC 1156.
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