ESO's GRAVITY instrument achieves first light
Astronomers have achieved first light with a powerful instrument that will allow scientists to probe the environments surrounding black holes. TheGRAVITY instrument is in the process of being installed in thetunnels below the ESO's Very Large Telescope (VLT) located at theParanal Observatory, Chile.
The newest addition tothe VLT uses a technique known as interferometry to harness the powerof the observatory, combining the collected light from numerousinstruments to form a single virtual telescope roughly 200 m (656 ft)across.
GRAVITY's first lighttest focused on a series of bright young stars known as the TrapeziumCluster located in the heart of the well known Orion Nebula. Not onlywas the instrument able to successfully combine light harvested fromthe VLT's four 1.8 m (5.9 ft) auxiliary telescopes into asingle unified image, it also made a discovery in the region of apreviously unknown component in the cluster – a double star knownas Theta Orionis F.
The first lighttest for GRAVITY represented the first time that four telescopes hadbeen stabilized simultaneously, allowing the instrument to takeexposures hundreds of times longer than previous attempts, with themost prolonged exposure lasting several minutes in length.
Successful completionof the first light tests represents a major milestone on the journeyto the commissioning of the instrument. Once fully operational, theGRAVITY instrument will allow astronomers to examine very faintobjects that would ordinarily be extremely difficult to observe withconventional methods.
GRAVITY will in effectserve as a sort of swiss army instrument for the VLT, capable offulfilling a wide range of applications. A primary task to beundertaken by GRAVITY in the early stages of its operational lifewill be to probe the environment prevailing around the event horizonof a black hole.
Our understanding ofthese regions is governed by Einstein's Theory of General Relativity,meaning that GRAVITY will be putting one of the scientific worldsmost venerable doctrines to the test.
That is the long termgoal, but in the near future the team will continue its work inintegrating GRAVITY with the VLT's four 8.2 m (26.9 ft) telescopes,readying the instrument for another test that is set to take placelater this year.