THE FIRST CONFIRMED MICROLENS IN A GLOBULAR CLUSTER

Journal Article · Tue Jan 10 04:00:00 EST 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/744/2/L18· OSTI ID:22047243

Pietrukowicz, P; Udalski, A ^[1]; Minniti, D; Alonso-Garcia, J ^[2]; Jetzer, Ph ^[3]

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1. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
2. Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Av. Vicuna MacKenna 4860, Casilla 306, Santiago 22 (Chile)
3. Institut fuer Theoretische Physik, Universitaet Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland)

In 2000 July/August a microlensing event occurred at a distance of 2.'33 from the center of the globular cluster M22 (NGC 6656), observed against the dense stellar field of the Milky Way bulge. We have used the adaptive optics system NACO at the ESO Very Large Telescope to resolve the two objects that participated in the event: the lens and the source. The position of the objects measured in 2011 July is in agreement with the observed relative proper motion of M22 with respect to the background bulge stars. Based on the brightness of the microlens components we find that the source is a solar-type star located at a distance of 6.0 {+-} 1.5 kpc in the bulge, while the lens is a 0.18 {+-} 0.01 M{sub Sun} dwarf member of the globular cluster located at the known distance of 3.2 {+-} 0.2 kpc from the Sun.

• OSTI ID: 22047243
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 744; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
BRIGHTNESS
DISTANCE
GRAVITATIONAL LENSES
MILKY WAY
OPTICS
PROPER MOTION
STAR CLUSTERS
SUN
TELESCOPES