We have performed the Fourier decomposition analysis of 8‐ and 13‐yr V‐band light curves of a carefully selected sample of 454 fundamental‐mode RR Lyrae variables (RRab type), detected in an ≃14 square degree area of the Small Magellanic Cloud (SMC) and listed in the Optical Gravitational Lensing Experiment, phase III, Catalogue of Variable Stars. The Fourier decomposition parameters were used to derive metal abundances and distance moduli, following the methodology described by Kapakos, Hatzidimitriou & Soszyński. The average metal abundance of the RRab stars on the new scale of Carretta et al. was found to be 〈[Fe/H]C09〉 = −1.69 ± 0.41 dex (std, with a standard error of 0.02 dex). A tentative metallicity gradient of −0.013 ± 0.007 dex kpc−1 was detected, with increasing metal abundance towards the dynamical centre of the SMC, but selection effects are also discussed. The distance modulus of the SMC was re‐estimated and was found to be 〈μ〉 = 19.13 ± 0.19 (std) in a distance scale where the distance modulus of the Large Magellanic Cloud (LMC) is μLMC = 18.52 ± 0.06 (std). The average 1σ line‐of‐sight depth was found to be σ int =5.3±0.4 kpc (std), while spatial variations of the depth were detected. The SMC was found to be deeper in the north‐eastern region, while metal‐richer and metal‐poorer objects in the sample seem to belong to different dynamical structures. The former have smaller scale height and may constitute a thick disc, its width being 10.40 ± 0.02 kpc, and a bulge whose size (radius) is estimated to be 2.09 ± 0.81 kpc. The latter seem to belong to a halo structure with a maximum depth along the line of sight extending over 16 kpc in the SMC central region and falling to ∼12 kpc in the outer regions.

We have performed the Fourier decomposition analysis of 11-yr V-band light curves of a carefully selected sample of 100 RR Lyrae variables, detected in the central regions of the Small Magellanic Cloud (SMC), with the Optical Gravitational Lensing Experiment, phases II and III. The sample consisted of 84 fundamental mode pulsators (RRab stars) and 16 firstovertone pulsators (RRc stars). The Fourier decomposition parameters were used to derive metal abundances and distance moduli for these RR Lyrae variables. The average metal abundance of the RRab stars on the new scale of Carretta et al. is found to be [Fe/H] C09 = −1.62 ± 0.41 dex (std, with a standard error of 0.05 dex). The distance modulus of the SMC was found to be μ = 18.90 ± 0.18 (std) from the RRab population in a distance scale where the distance modulus of the Large Magellanic Cloud (LMC) is μ LMC = 18.52 ± 0.06 (std). The 1σ line-of-sight depth for the RRab stars was found to be σ int = 4.13 ± 0.27 kpc, in good agreement with that estimated from red clump stars and eclipsing binaries. There is a clear indication that the metal-poorer and metal-richer objects in the sample may belong to different dynamical structures. The metal-rich stars have smaller scaleheight and could be part of a disc-like structure, while the more metal poor objects could be part of a much thicker structure, such as an inner halo or a bulge component.

The presentation of new results from an [O iii] 5007‐Å survey in a search for planetary nebulae (PNe) in the Galactic bulge is continued. A total of 60 objects, including 19 new PNe, have been detected in the remaining 34 per cent of the survey area, while 41 objects are already known. Deep Hα+[N ii] CCD images as well as low‐resolution spectra have been acquired for these objects. Their spectral signatures suggest that the detected emission originates from photoionized nebulae. In addition, absolute line fluxes have been measured and the electron densities are given. Accurate optical positions and optical diameters are also determined.