Multicolor ( BVRI ) light curves of the eclipsing novalike variable TT Tri are presented .
The eclipse profiles are analyzed with a parameter-fitting model that assumes four sources of luminosity : a white dwarf primary star , a main-sequence secondary star , a flared accretion disk with a rim , and a bright spot at the intersection of the mass-transfer stream and the disk periphery .
Model parameters include the temperatures of the white dwarf ( T _ { 1 } ) and the secondary star ( T _ { 2 } ) , the radius ( R _ { \mathrm { d } } ) and temperature ( T _ { \mathrm { d } } ) of the disk periphery , the inner disk radius ( R _ { \mathrm { in } } ) , the disk power-law radial brightness temperature exponent ( \alpha ) and thickness parameter ( h _ { \mathrm { r } } ) , and a bright spot temperature enhancement factor ( \chi _ { \mathrm { s } } ) .

A grid of model model light curves was computed , covering an extensive range of plausible parameter values .
The models were then compared with the mean BVRI light curves to determine the optimum values for the fitting parameters and their associated errors .
The mass ratio of TT Tri is poorly constrained in our models , but must lie roughly in the range 0.3 \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$ } } } \hbox { $ < $ } } } % ~ { } q ( = M _ { 2 } / M _ { 1 } ) \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$% } } } \hbox { $ < $ } } } 0.9 .
Models characterized by mass ratios of q = 0.3 ( i = 76.1 ^ { \circ } ) , q = 0.6 ( i = 72.6 ^ { \circ } ) , and q = 0.9 ( i = 70.4 ^ { \circ } ) were all capable of providing acceptable fits to the data , although the best fits were achieved for mass ratios near the upper end of the permitted range ( q = 0.6 and q = 0.9 ) .
The values of the remaining fitting parameters were found to be insensitive to the adopted mass ratio and rim thickness .
The accretion disk was found to extend to \sim 50 - 60 % of the distance to the inner Lagrangian point in all models , but came closer to reaching the tidal limit ( as expected for steady-state accretion ) in the higher mass ratio models .
The same behavior was found for the radial temperature profile of the disk , which increased with mass ratio , becoming more consistent with that expected for steady state accretion in the q = 0.6 and q = 0.9 models .
Models with a truncated inner disk ( R _ { \mathrm { in } } > > R _ { 1 } ) generally resulted in a higher white dwarf temperature , and a steepening of the disk temperature profile , but were not required to achieve a viable steady-state disk solution .
No evidence was found for a luminous bright spot in the system , which is not surprising given the lack of a pre-eclipse “ hump ” in the light curve .

A total of 22 eclipse timings were measured for the system , which yielded an ephemeris for the times of mid-eclipse given by { JD } _ { \odot } = 2 , 453 , 618.953 ( 3 ) +0.1396369 ( 4 ) ~ { } E .
A comparison of the observed brightness and color at mid-eclipse with the photometric properties of the best-fitting model suggests that TT Tri lies at a distance of \sim 400 - 500 pc .