The observations of the tightly packed cluster used Gemini Observatory’s powerful
adaptive optics system at the Gemini South
telescope in Chile.
A technical jewel named GeMS (derived from
“Gemini Multi-conjugate adaptive optics
System”), in combination with the powerful
infrared camera Gemini South Adaptive Optics Imager (GSAOI), was able to penetrate
the dense fog surrounding Liller 1 and to
provide astronomers with this unprecedented view of its stars.
This has been made possible thanks to the
combination of two specific characteristics
of GeMS: first, the capability of operating
at near-infrared wavelengths (especially in
the K pass-band); second, an innovative and
revolutionary way to remove the distortions
(blurriness) that the Earth’s turbulent atmosphere inflicts on astronomical images.
To compensate for the degrading effects of
the Earth’s atmosphere, the GeMS system
uses three natural guide stars, a constellation of five laser guide stars, and multiple
deformable mirrors. The correction is so fine
that astronomers are provided with images
of unparalleled sharpness.
In the best K-band exposures of Liller 1, stellar images have an angular resolution of
only 75 milliarcseconds, just slightly larger
than the theoretical limit (known as the diffraction limit) of Gemini’s 8-meter mirror.
This means that GeMS almost perfectly corrected Earth’s atmospheric distortions.
The international research team published
the results in the June 15th issue of The Astrophysical Journal (volume 806, page 152).
The astro-ph version of the article can be
found here.
The results achieved on Liller 1 have been so
important that the research team is currently expanding their work to other globular
clusters, which promise to deliver even more
exciting science.
January 2016
Background:
Stellar Collisions
Stellar collisions are important because
they can provide the key to understanding how certain exotic objects, which cannot be explained by the passive evolution
of single stars, originate. “Blue Stragglers,“
for instance, are old stars that mysteriously
appear younger than they should be; these
exotic stars may be formed by nearly headon collisions that cause the stars to merge,
mixing their nuclear fuel and restoking the
fire of nuclear fusion. But collisions can also
involve binary systems, with the effect of
shrinking the ini F