Ton 320

Ton 320, also known as TK 1, is one of the more enigmatic planetary nebulae in our galaxy. This faint and elusive nebula has been hardly explored by astronomers and, remarkably, has only been photographed on two separate occasions. As a result, our understanding of its properties remains very limited.

The central star of Ton 320 plays a crucial role in the nebula's appearance. Its effective temperature has been estimated through careful analysis of the available data, suggesting that it is hot enough to ionize the surrounding gas, which in turn creates the glowing shell we observe. Interestingly, observations in the near-infrared have hinted at an unusual excess in the K-band, though the uncertainties in these measurements are significant.

Because of its rarity and the sparse amount of data—bolstered by the fact that there are only a couple of photographic records—Ton 320 remains a prime target for further investigation.