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ngc 869 and ngc 884 ( @xmath0 and @xmath1 persei , respectively ) are a well known double cluster rich in massive b - type stars , and have been the focus of many studies over the years . recent studies show that ngc 869 and ngc 884 have nearly identical ages of @xmath8 1314 myr , common distance moduli of dm @xmath8 11.85 , and common reddenings of e(b - v ) @xmath8 0.50.55 ( ( * ? ? ? * currie et al .  2009 ) , ( * ? ? ? * slesnick et al .  2002 ) , ( * ? ? ? * bragg & kenyon 2005 ) ) . * currie et al . ( 2008 ; hereafter c08 ) ) identified two populations of ngc 869 and ngc 884 stars with detected spitzer mips-24 @xmath9 m excess emission : 20 a and f - type stars with luminous debris disk emission and 57 brighter , earlier stars with weaker excess emission . they identify most of the latter group as candidate be stars . however , only 21 were previously listed as be stars ( eg . * bragg & kenyon 2002 ) , ( * ? ? ? * slesnick et al .  2002 ) ) .    in this study , we analyze blue optical spectra of 92 early - type cluster members , including 16 candidate be stars from c08 , and investigate their near - to - mid infrared ( ir ) excesses . with continued monitoring of these stars in the both the optical and ir regimes , we hope to explore these excesses as a reasonable means for identifying potential be stars within clusters , as well as to investigate the transient natures of the disks surrounding the known be stars in ngc 869 and ngc 884 . blue optical spectra of 92 members of ngc 869 and ngc 884 were obtained on 2005 november 1415 using the wiyn 3.5 m telescope with the hydra spectrograph . the observed spectra cover a wavelength range of 42504900  .    shown in figure 1 are samples of the model spectral fits used to measure values for @xmath2 sin @xmath3 , @xmath4 , and log @xmath10 for b - type stars . @xmath2 sin @xmath3 was determined by comparing the he i @xmath114387 , 4471 , 4713 , and mg ii @xmath124481 lines with the kurucz atlas9 models ( ( * ? ? ? * kurucz 1994 ) ) and taking a weighted average of these four values . for stars having @xmath4 @xmath13 15000 k , the tlusty bstar2006 models ( ( * ? ? ? * lanz & hubeny 2007 ) ) were used to find @xmath4 and log @xmath10 using the h@xmath14 line . for stars having @xmath4 @xmath15 15000 k , the kurucz atlas9 models were used ( ( * ? ? ? * kurucz 1994 ) ) . the method of ( * ? ? ? * huang & gies ( 2006 ; hereafter hg06 ) ) was used to determine log @xmath5 . for be stars , strmgren photometry available from the webda database was used to derive @xmath4 and log @xmath5 based on the methods of ( * ? ? ? * mcswain et al .   ( 2008 ) ) . the masses and radii for all stars were determined from the schaller et al . ( 1992 ) evolutionary tracks , which are shown plotted with @xmath4 and log @xmath5 in figure 2 .     and on the right is he i @xmath124378 . the solid line is our observed spectrum while the dashed line displays our model fit to the line , with the computed residual shown above , shifted for clarity . , title="fig : " ]   and on the right is he i @xmath124378 . the solid line is our observed spectrum while the dashed line displays our model fit to the line , with the computed residual shown above , shifted for clarity . , title="fig : " ]     and log @xmath5 are plotted with the evolutionary tracks of ( * ? ? ? * schaller et al .   ( 1992 ) ) . the zams mass of each evolutionary track is labeled along the bottom . normal b - type stars are shown as open diamonds while be stars are filled diamonds . , title="fig : " ]   and log @xmath5 are plotted with the evolutionary tracks of ( * ? ? ? * schaller et al .   ( 1992 ) ) . the zams mass of each evolutionary track is labeled along the bottom . normal b - type stars are shown as open diamonds while be stars are filled diamonds . , title="fig : " ] sixteen be candidates from c08 are present in our sample or that of hg06 . three of these 16 stars show no evidence of circumstellar emission in our spectra , though all have been observed to be be stars in the past ( ( * ? ? ? * keller et al .  2001 ) ) . ten of the c08 be candidates in our spectra do show emission . stellar parameters for the remaining three candidates are found in hg06 , thus we can not comment on the presence of emission at the time of observation . in addition , we find be emission in one star ( no . 1772 ) that was not observed by c08 , and we present results for one additional star ( no . 1268 ) identified as a be star by ( * ? ? ? * keller et al .  ( 2001 ) ) . these results are summarized in table 1 . .measured physical parameters for be stars [ cols="<,^,^,^,^,^,^ , < , < " , ]      + @xmath16 identification numbers from the webda database . @xmath17 be candidate in c08 . @xmath18 stars not showing emission in our observations are likely transient be stars . @xmath19 identified as be star by ( * ? ? ? * keller et al .  ( 2001 ) ) . [ sed ]    spectral energy distributions ( seds ) for three stars in ngc 869 and ngc 884 are displayed in figure 3 . ubv magnitudes are from the webda database , jhk@xmath20 are from the 2mass survey , and spitzer [ 8 ] and [ 24 ] @xmath9 m are from c08 . these magnitudes were then converted to fluxes via the methods detailed in ( * ? ? ? * bessell et al . ( 1998 ) ) , ( * ? ? ? * cohen et al .  ( 2003 ) ) , ( * ? ? ? * colina et al .  ( 1996 ) ) , ( * ? ? ? * reach et al . ( 2005 ) ) , and ( * ? ? ? * rieke et al .  ( 2008 ) ) . assuming a constant @xmath21 = 0.52 for ngc 869 and ngc 884 ( ( * ? ? ? * bragg & kenyon 2005 ) , ( * ? ? ? * slesnick et al .  2002 ) ) , reddened blackbody curves have been overlaid with these plots to investigate their near - to - mid ir excesses . all three stars shown in figure 3 are proposed be candidates ( c08 ) , with ngc 884 - 2138 and ngc 869 - 49 having emission present in our optical spectra and observed near - to - mid ir excess . ngc 884 - 2165 is not in our spectroscopic sample but has previously been identified as a be star and has observed ir excess ( ( * ? ? ? * keller et al . we have measured the physical parameters of 77 b - type stars and 15 be stars in ngc 896 and ngc 884 . sixteen be candidates from c08 are present in our sample or that of hg06 . of these 16 be candidates , 3 stars show no evidence of emission in our optical data and are likely transient be stars . ten of these be candidates do show emission in our spectra . those be candidates without emission in our spectra should be monitored in the future to further investigate their transient nature .    in the future , irac 3.6 - 5.8 @xmath9 m data will be combined with the optical and ir fluxes used here to investigate the observed seds . we will fit the new seds using modern flux models rather than blackbody curves . modifications accounting for variable reddening throughout the clusters will also be made . these new sed fits can then be used to model the be disk sizes and temperatures . we are grateful for travel support provided by the american astronomical society and the international astronomical union . we would like to thank yale university for providing access to the wiyn telescope at kpno . institutional support was provided by lehigh university . this work was also supported by nasa dpr number nnx08av70 g . rieke , g.  h. , blaylock , m. , decin , l. , engelbracht , c. , ogle , p. , avrett , e. , carpenter , j. , cutri , r.  m. , armus , l. , gordon , k. , gray , r.  o. , hinz , j. , su , k. , & willmer , c.  n.  a. 2008 , _ aj _ , 135 , 2245
we present blue optical spectra of 92 members of @xmath0 and @xmath1 per obtained with the wiyn telescope at kitt peak national observatory . from these spectra , 
 several stellar parameters were measured for the b type stars , including @xmath2 sin @xmath3 , @xmath4 , log @xmath5 , @xmath6 , and @xmath7 . 
 strmgren photometry was used to measure @xmath4 and log @xmath5 for the be stars . 
 we also analyze photometric data of cluster members and discuss the near - to - mid ir excesses of be stars .