Blue stars steal the show in NGC 2031

NASA’s Hubble House Telescope picture of the star-filled globular cluster NGC 2031 is furthering scientists’ understanding of “stellar contamination,” or probably a rejuvenated class of stars referred to as “blue stragglers.”

Positioned within the Massive Magellanic Cloud (LMC) within the constellation Mensa the Desk Mountain, NGC 2031, like all globulars, shows a spherical form as a consequence of long-term mutual gravitational interactions between many elderly stars. Astronomers usually have problem measuring the distances to the cluster’s stars as a result of the density of the LMC area it is positioned in leads to what is named stellar contamination — the place the atmospheres and floor options of the cluster’s tightly packed stars intervene with observations.

In accordance with a NASA release, contamination may clarify why NGC 2031 shows so many vivid blue stars close to its core (pictured on the high left nook of the picture above). These bluer stars are considerably out-of-place in a globular cluster as a result of they usually burn scorching and die younger, whereas most globulars are residence to a lot older crimson stars.

However one other attainable rationalization for the blue stars on this globular is that they’re a sort of star often called a blue straggler. These second-chance stars are considered the results of two older crimson stars merging. The mixed mass of the ensuing star makes it burn extra intensely, giving it a younger look that appears misplaced in a globular cluster. Hubble beforehand discovered potential proof for such stars in a distinct cluster, 47 Tucanae.

Whereas NGC 2031 is comparatively cramped and exhausting to review for a globular cluster, primarily based on the area’s 14 Cepheid variable stars — stars that brighten then dim in common durations — astronomers have been in a position to pin down the clusters distance to about 150,000 light-years. The cluster is simply 140 million years outdated and holds some 3,000 instances the mass of the Solar.