Context : The internal structure of pre-main-sequence ( PMS ) stars is poorly constrained at present .
This could change significantly through high-quality asteroseismological observations of a sample of such stars .

Aims : We concentrate on an asteroseismological study of HD 261711 , a rather hot \delta  Scuti-type pulsating member of the young open cluster NGC 2264 located at the blue border of the instability region .
HD 261711 was discovered to be a pre-main sequence \delta  Scuti star using the time series photometry obtained by the MOST satellite in 2006 .

Methods : High-precision , time-series photometry of HD 261711 was obtained by the MOST and CoRoT satellites in four separate new observing runs that are put into context with the star ’ s fundamental atmospheric parameters obtained from spectroscopy .
Frequency Analysis was performed using Period04 .
The spectral analysis was performed using equivalent widths and spectral synthesis .

Results : With the new MOST data set from 2011/12 and the two CoRoT light curves from 2008 and 2011/12 , the \delta  Scuti variability was confirmed and regular groups of frequencies were discovered .
The two pulsation frequencies identified in the data from the first MOST observing run in 2006 are confirmed and 23 new \delta  Scuti-type frequencies were discovered using the CoRoT data .
Weighted average frequencies for each group were determined and are related to l = 0 and l = 1 p -modes .
Evidence for amplitude modulation of the frequencies in two groups is seen .
The effective temperature ( T _ { \mathrm { eff } } ) was derived to be 8600 \pm 200 K , \log g is 4.1 \pm 0.2 , and the projected rotational velocity ( { \upsilon } \sin i ) is 53 \pm 1 \mathrm { km s } ^ { -1 } .
Using our T _ { \mathrm { eff } } value and the radius of 1.8 \pm 0.5 R _ { \odot } derived from spectral energy distribution ( SED ) fitting , we get a luminosity log L / L _ { \odot } of 1.20 \pm 0.14 which agrees well to the seismologically determined values of 1.65 R _ { \odot } and , hence , a log L / L _ { \odot } of 1.13 .
The radial velocity of 14 \pm 2 \mathrm { km s } ^ { -1 } we derived for HD 261711 , confirms the star ’ s membership to NGC 2264 .

Conclusions : Our asteroseismic models suggest that HD 261711 is a \delta  Scuti-type star close to the zero-age main sequence ( ZAMS ) with a mass of 1.8 to 1.9 M _ { \odot } .
With an age of about 10 million years derived from asteroseismology , the star is either a young ZAMS star or a late PMS star just before the onset of hydrogen-core burning .
The observed splittings about the l = 0 and 1 parent modes may be an artifact of the Fourier derived spectrum of frequencies with varying amplitudes .