(Proposal ID) S17A-075 (PI) Otsuka, Masaaki (Proposal Title) Investigations of warm-cold dust mass and gas-to-dust mass ratio in LMC PNe (Abstract) Material recycling between stars and the interstellar medium (ISM) has chemically enriched galaxies. The total ISM dust and gas masses in evolved galaxies can be provided by total ejected dust and gas masses from evolved stars. However, this view has been recently questioned by analysing the stellar dust mass yield in the Magellanic Clouds (MCs); the amount of dust mass produced by asymptotic giant branch (AGB) stars and supernovae can account for only about 2-3% of the total ISM dust mass in the MCs. Investigation of the cold stellar warm-cold dust component using the far-IR data and the gas-to- dust mass ratio (GDRs) would be necessary to understanding material recycling in galaxies. By taking several advantages of PNe, we propose a test study on the warm-cold masses and the GDRs in 11 LMC PNe. We aim to (1) quantify the dust and gas masses by SED fittings with UV through far-IR data, (2) characterise PNe and their central stars' evolution using metal abundances and central stars' parameters, (3) compare the dust masses with/without far-IR data, and (4) investigate the correlations amongst the dust masses, GDRs, and the metallicities. GMOS observations are essential to determine physical parameters of the dusty ionised nebulae and the central stars.