PIA09961: Mira's Tail There All Along
Target Name: Mira
Mission: Galaxy Evolution Explorer (GALEX)
Spacecraft: GALEX Orbiter
Instrument: Ultraviolet/Visible Camera
Product Size: 1569 x 1600 pixels (width x height)
Produced By: California Institute of Technology
Full-Res TIFF: PIA09961.tif (7.544 MB)
Full-Res JPEG: PIA09961.jpg (471.7 kB)

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Original Caption Released with Image:

NASA's Galaxy Evolution Explorer discovered an exceptionally long comet-like tail of material trailing behind Mira -- a star that has been studied thoroughly for about 400 years. So, why had this tail gone unnoticed for so long? The answer is that nobody had scanned the extended region around Mira in ultraviolet light until now.

As this composite demonstrates, the tail is only visible in ultraviolet light (top), and does not show up in visible light (bottom). Incidentally, Mira is much brighter in visible than ultraviolet light due to its low surface temperature of about 3,000 kelvin (about 5,000 degrees Fahrenheit).

The Galaxy Evolution Explorer, one of NASA's Small Explorer class missions, is the first all-sky survey in ultraviolet light. It found Mira's tail by chance during a routine scan. Since the mission's launch more than four years ago, it has surveyed millions of galaxies and stars. Such vast collections of data often bring welcome surprises, such as Mira's unusual tail.

The visible-light image is from the United Kingdom Schmidt Telescope in Australia, via the Digitized Sky Survey, a program affiliated with the Space Telescope Science Institute, Baltimore, Md.

Image Credit:
NASA/JPL-Caltech/POSS-II/DSS

Image Addition Date:
2007-08-15