Classical Cepheids behind the Galactic bulge

Department of Astronomy, The University of Tokyo, Japan

Abstract

Severe interstellar extinction toward the Galactic plane has prevented the investigation of stellar populations in that region. Pulsating variable stars, particularly Cepheids and Miras, are useful tracers because their distances and ages can be determined accurately. Infrared observations of these variable stars in the obscured regions can provide useful information about the hidden parts of the Galaxy. These objects can also provide complimentary information to observations made by the Gaia spacecraft because highly-obscured objects cannot be detected by Gaia. We have carried out a near-infrared survey of variable stars near the Galactic bulge, between − 10 and + 10 degrees in galactic longitude, using the IRSF 1.4 m telescope and SIRIUS near-infrared camera in South Africa. Here as an initial result we report the discovery of 19 classical Cepheids behind the bulge.