Red giant stars are many, and yet still a little hard to come by, as
only a few public images of whatever is within 1000 light years seem
to exist that fit within the color saturated eye-candy profiles that
we’ve been taught to accept. However, the visible spectrum is
extremely limited as to what is otherwise technically accessible from
just above and below our genetically limited and thus inferior visual
spectrum. (seems entirely odd that our human evolution was so careless
in having discarded so much visual capability, in that other creatures
seem to have a far wider visual spectrum capability that includes some
UV and IR)

“Red Giant Star Found to Have Massive Tail”
http://www.efluxmedia.com/news_Red_G...l_077 84.html
Mira A of several hundred solar radii (UV colorized as bluish): “A
dying star situated 400 light years away from us exhibits an unusual
and massive tail of heated gas that spreads for more than 13 light
years.”
http://en.wikipedia.org/wiki/Mira
http://www.nasa.gov/mission_pages/galex/20070815/a.html

Sirius B could have been much like an image of Mira A, except a whole
lot larger (1000 solar radii), as viewed in visible and near IR
http://xmm.esac.esa.int/external/xmm...aab_v2_col.pdf

Mira A and lots more composite observationology from FAS
http://www.fas.org/irp/imint/docs/rst/Sect20/A6.html

There are many possibilities, as for how Sirius B used to function as
a truly massive (9 solar mass) star, thereby extremely hot and fast
burning prior to becoming a red supergiant, creating an impressive
planetary nebula phase before ending as the little white dwarf. For
all we know Sirius B was even a variable kind of red giant and then
perhaps a slow nova flashover phase prior to finishing off as the
white dwarf.

These following examples are probably similar or perhaps representing
a slightly smaller version of what the Sirius star/solar system looked
like once Sirius B had started turning itself from an impressive red
supergiant into a white dwarf of perhaps 1/8th its original mass,
taking roughly 64~96,000 years for this explosive mass shedding phase
to happen. A few tens of billions of years later is when such a white
dwarf eventually becomes a black dwarf, kind of black diamond spent
star, in that our universe may or may not be quite old enough to
display such examples.
http://en.wikipedia.org/wiki/Planetary_nebula
http://en.wikipedia.org/wiki/Helix_Nebula
http://en.wikipedia.org/wiki/Cat%27s_Eye_Nebula
http://apod.nasa.gov/apod/ap031207.html
http://www.uv.es/jrtorres/index6.html

Betelgeuse has been a massive red giant at 20+ fold the mass of our
sun, and likely worth nearly 3 fold the mass of the original Sirius B,
and currently expanded to 1000 solar radii, and it'll be truly
impressive nova whenever it transforms into a white dwarf nearly the
size of Jupiter.

The soon to be renewed and improved Hubble should accomplish the
improved spectrum and resolution of most everything, along with other
existing and soon to be deployed telescopes should give us even better
composite examples of what Sirius B used to look like. This may give
some of us a better interpretation as to what transpired right next
door to us, as well as having unavoidably contributed to some of what
our solar system has to offer.

~ BG