Description
A 'complete' sample of 174 M giants classified in the mid-1980s by Blanco (1986AJ.....91..290B) and later than subtype M0 in the NGC 6522 Baade's Window clear field has been investigated to establish some general properties of cool bulge stars. Photometric information has been obtained from the MACHO data base to search for variability and, where possible, to determine periods. Near- and mid-infrared magnitudes have been extracted from DENIS (<B/denis>) and ISOGAL (<II/243>). 46 semiregular variables (SRVs) and two irregular variables were found amongst the 174. Many M5 and all stars M6 or later show variation, whereas earlier subtypes (M1-M4) do not.
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