RY Sagittarius is a fine R Coronae Borealis star coming back into easy view as we enter the Milky Way bulge season. The R CrB stars are highly evolved objects whose origin remains somewhat mysterious. They are perhaps the product of the merger of two white dwarf stars, or are single stars in an extremely late and mass-losing stage of evolution. They vary when they are obscured by carbon dust surrounding the star.
RY Sgr hasn't exhibited very long fades in nearly a decade -- it has undergone deep dips, but recovered quickly. It's possible that it's heading for another fade now, and the months of June, July, and August are a fine season to observe this star and all the other sights of the Milky Way bulge. Catch it if you can!