  We report on the discovery of the optical counterpart to the neutron star
soft X-ray transient (SXT) XTE J1709-267 in outburst and quiescence. We further
report the detection of type I bursts in RXTE data obtained during an outburst
of the source in 2002. These bursts show a precursor event before the onset of
the main burst event, reminiscent of photospheric radius expansion bursts.
Sifting through the archival RXTE data for the burster 4U 1636-53 we found a
nearly identical burst with precursor in 4U 1636-53. A comparison of this burst
to true photospheric radius expansion bursts in 4U 1636-53 leads us to conclude
that these bursts-with-precursor do not reach the Eddington limit. We further
report on the analysis of a 22.4 ksec observation of XTE J1709-267 obtained
with the Chandra satellite when the source was in quiescence. We found that the
source has a soft quiescent spectrum which can be fit well by an absorbed black
body or neutron star atmosphere model. A power law contributes less than 10 per
cent to the 0.5-10 keV unabsorbed flux of (1.0+-0.3)x10^-13 erg cm^-2 s^-1.
This flux is the same within the errors as the flux measured right after the
outburst in 2002, indicating that the quiescent flux was reached within a few
weeks after the outburst. Finally, we compared the power-law fractional
contribution to the unabsorbed 0.5-10 keV luminosity for neutron star SXTs in
quiescence for which the distance is well-known. We find that the power-law
contribution is low only when the source quiescent luminosity is close to
\~1-2x10^33 erg s^-1. Both at higher and lower values the power-law
contribution to the 0.5-10 keV luminosity increases. We discuss how models for
the quiescent X-ray emission can explain these trends.(Abridged)
