Monitoring luminous yellow massive stars in M 33: new yellow hypergiant candidates

Searching for new yellow symbiotic stars: positive identification of StHα63

Yellow symbiotic stars are useful targets to probe whether mass transfer has happened in these binary systems. However, the number of known yellow symbiotic stars is very scarce. We report spectroscopic observations of five candidate yellow symbiotic stars selected by their position in the 2MASS (J−H) versus (H−Ks) diagram and included in some emission-line catalogs. Among the five candidates, ...

New Yellow Ba0.93Eu0.07Al2O4

Young massive stellar populations in M 33

In this paper we estimate the ratio OB stars to red supergiants (OB/R) as a function of the distance from the centre of M 33. We found a gradient of the ratio (OB/R) really exists. Our study is based on a new approach in estimating the errors on the ratio (OB/R). On the other hand, by applying a new correlation technique between OB star candidates and red supergiant candidates in the central re...

The Ofpe/wn9 Stars in M 33

We present HST/STIS Ultraviolet spectra of the six known Ofpe/WN9 stars (“slash stars”) in M 33. These stars were selected for showing the characteristics of the Ofpe/WN9 class from previous optical ground-based spectroscopy. The UV spectra are rich in wind lines, whose strength and terminal velocity vary greatly among our target sample. We analyse the STIS spectra with non-LTE, line blanketed,...

Visualization of mitochondria in living cells with a genetically encoded yellow fluorescent protein originating from a yellow-emitting luminous bacterium.

We have visualized redox and structural changes in the mitochondria of yeast Saccharomyces cerevisiae as a eukaryotic cell model using a genetically encoded yellow fluorescent protein (Y1-Yellow) and conventional fluorescence microscopy. Y1-Yellow originating from a yellow emitting luminous bacterium Aliivibrio sifiae Y1 was fused with a mitochondria-targeted sequence (mt-sequence). Y1-Yellow f...