?Ratio of dark to luminous mass inside solar circle Ro?

In article ,
stargene writes:
But when I recently checked some sources, eg: wikipedia's
entry: "Milky Way", the graphs showed that the sun's
observed velocity datum point set dead on top of both
the observed "flat velocity curve" of spirals and on
top of the non-observered Keplerian curve which would
only result from there being no dark matter interior
to the sun at all.

You have misinterpreted something. The red curve shows what would be
expected from stars alone (though I'm slightly surprised there is a
good estimate, given the amount of dust extinction). The blue curve
shows the observations, which differ considerably from the red curve,
presumably as a result of dark matter. This is explained in the
text, specifically the second paragraph of "Galactic rotation."

The curves meet at the solar circle because they are normalized
there. One thing we know pretty well is the Sun's speed around the
Milky Way center, so all curves have to go through that speed.

References for the graph seem to be textbooks and not all that
recent, so there may be better data today. In particular, Mark Reid
and his group have done a lot of work with maser VLBI in the last
decade or so.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA