The parameters for the newly-discovered open cluster Alessi 95 are established on the basis of available photometric and spectroscopic data , in conjunction with new observations .
Colour excesses for spectroscopically-observed B and A-type stars near SU Cas follow a reddening relation described by E _ { U - B } / E _ { B - V } = 0.83 + 0.02 E _ { B - V } , implying a value of R = A _ { V } / E _ { B - V } \simeq 2.8 for the associated dust .
Alessi 95 has a mean reddening of E _ { B - V } { ( B 0 ) } = 0.35 \pm 0.02 s.e. , an intrinsic distance modulus of V _ { 0 } - M _ { V } = 8.16 \pm 0.04 s.e .
( \pm 0.21 s.d .
) , d = 429 \pm 8 pc , and an estimated age of 10 ^ { 8.2 } yr from ZAMS fitting of available UBV , CCD BV , NOMAD , and 2MASS JHK _ { s } observations of cluster stars .
SU Cas is a likely cluster member , with an inferred space reddening of E _ { B - V } = 0.33 \pm 0.02 and a luminosity of \langle M _ { V } \rangle = -3.15 \pm 0.07 s.e. , consistent with overtone pulsation ( P _ { FM } = 2 ^ { d } .75 ) , as also implied by the Cepheid ’ s light curve parameters , rate of period increase , and Hipparcos parallaxes for cluster stars .
There is excellent agreement of the distance estimates for SU Cas inferred from cluster ZAMS fitting , its pulsation parallax derived from the infrared surface brightness technique , and Hipparcos parallaxes , which all agree to within a few percent .