Fig. 1. HST WFPC2 V image of SBS 0335-052 showing the high surface brightness super-star clusters. At a distance of 54.3 Mpc, 1 arcsec corresponds to a linear size of 263 pc

Fig. 2. (V-I) color vs. distance from the brightest super-star cluster at the SE tip of SBS 0335-052. The color gets redder with increasing distance

Fig. 3. (V-I) color map of SBS 0335-052. Blue is dark, red is light. The dust patches on top of the super-star clusters are clearly seen

Fig. 4. Same V image as in Fig. 1, with the contrast adjusted to show the low surface brightness underlying component of SBS 0335-052. The supershell delineating the large supernova cavity is clearly seen

Fig. 5 (U-B) color profile (labeled E) of SBS 0335-052. The color is very blue and the profile flat

Fig. 6. HST GHRS spectrum of SBS 0335-052 around the Lyα line. A strong damped Lyα absorption is seen along with several heavy element interstellar absorption lines

Fig. 7. HST WFPC2 I image of SBS 1415+437. The shape is cometary-like. A bright supergiant H II region at the SW end, resolved stars in the body of the galaxy and unresolved diffuse stellar emission can be seen. The different regions used for stellar population color-magnitude diagram analysis are marked

Fig. 8. Color-magnitude diagrams of stellar populations in the different regions of SBS 1415+437 as defined in Fig. 7. There is a systematic age increase from region I to region VI, implying propagating star formation from the NE to the SW

Fig. 9. MMT spectrum of region V (see Fig. 7) of SBS 1415+437. The upper panel shows the spectrum uncorrected for extinction, while the lower panel shows the same spectrum corrected for extinction. The best-fit model gives an age between 30 and 100 Myr

Fig. 10. Ne/O, Si/O, S/O and Ar/O abundance ratios vs. O abundance for the BCD sample of Izotov & Thuan (1998c). The solid lines show the ratios predicted by models of nucleosynthesis (Woosley & Weaver 1995)

Fig. 11. C/O, N/O and Fe/O abundance ratios vs. O abundance for the BCD sample of Izotov & Thuan (1998c). The solid lines for C/O show the ratios predicted by models of nucleosynthesis (Woosley & Weaver 1995) for high-mass stars. The dashed lines represent the predicted ratio for the contribution of both high- and intermediate-mass stars

Fig. 12. HST GHRS spectrum of T1214-277 around the Lyα line. There is Lyα emission and a N V λ1240 line with a conspicuous P Cygni profile

Fig. 13. Spectrum of SBS 0335-052 showing the P Cygni profiles of the Si λ1394 and λ1403 interstellar absorption lines

Fig. 14. Linear regressions of (a) the helium mass fraction Y vs. oxygen abundance and (b) the helium mass fraction Y vs. nitrogen abundance for the sample of 45 H II regions in BCDs of Izotov & Thuan (1998b). 1 σ alternatives are shown by dashed lines

Fig. 15. The abundances of c) ⁴He; d) D and e) ⁷Li as a function of η₁₀ ≡ 10¹⁰η, where η is the baryon-to-photon number ratio, as given by the standard hot big bang nucleosynthesis model