Symbiotic Star Mira HM Sge

A Hubble Space Telescope image of the symbiotic star Mira HM Sge. Located 3,400 light-years away in the constellation Sagitta, it consists of a red giant and a white dwarf companion. The stars are too close together to be resolved by Hubble. Material bleeds off the red giant and falls onto the dwarf, making it extremely bright. This system first flared up as a nova in 1975. The red nebulosity is evidence of the stellar wind. The nebula is about one-quarter light-year across.

About the colours

These images are a composite of separate exposures acquired by the WFC3/UVIS instrument on the Hubble Space Telescope. Several filters were used to sample various wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue= F502N, Green= F656N, Red= F658N

About the data

The HST observations include those from program 16492 (S. Goldman). Image Processing: Joseph DePasquale (STScI)