Philip Yock
, PASA, 17 (1), 35.
Next Section: Stellar Atmospheres
Title/Abstract Page: Observations from Australasia using
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Stellar Spectra
A beautiful application of gravitational microlensing uses the amplification of the effect to effectively increase the size of a telescope to carry out observations of faint objects that would otherwise be impossible. The feasibility of this application has been ably demonstrated by Lennon et al. (1996, 1997) and by members of the MACHO group (Minniti et al. 1998). Minniti et al. measured the abundance of the rare element lithium in a main sequence bulge star using Keck I when the star was magnified by
1 magnitude, thereby effectively converting the diameter of the telescope to 15m. The microlensing event that was used for this application was MACHO-97-BLG-45, the forty-fifth event found towards the galactic bulge during 1997 by the MACHO group. This application of gravitational microlensing utilises the achromaticity of the effect, and also the predictability of the time of peak amplification once an event has commenced. The latter feature allows the requisite telescope scheduling to be readily carried out. The above lithium abundance measurement would not have been possible using conventional techniques and existing telescopes. Further such measurements are expected to determine the chemical composition and enrichment history of the bulge. Next Section: Stellar Atmospheres
Title/Abstract Page: Observations from Australasia using
Previous Section: Galactic Bar
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