As already discussed in Sect. 2, the amplitude 
of the radial velocity
curve of the primary component has two probable values (Popper 1989) and hence
is uncertain. Taking 
, one gets, from the presently derived
photometric mass ratio 
of 0.1985, a value of 
for . This value of is almost the same(within errors) as that of 
derived by Popper (1989) from H lines for which the systemic velocity,
V0, is the same as that for the cooler component. Hence, we conclude that,
within observational errors, the derived photometric mass ratio is equal to
that of the spectroscopic mass ratio obtained by Popper (1989) from the H lines
and hence would yield reliable absolute elements. Combining the values of
and with the other required parameters from Table 2 (click here)
and using the relevant equations, we derived the absolute elements of AU Mon
with their errors, as given in Table 3 (click here).
Bolometric corrections (B.C) of 
for the primary and 
for the secondary
are used (Popper 1980). In deriving 
, we used 
and 
.
As the light curve of only one pass band is available for analysis, it is not
possible to derive the colours of the individual components and find their
spectral types. However, the derived temperature of 6000 K and bigger
size 
of the secondary component with a log g value of 2.5 suggest
it to be of spectral type F9-G0III-II (Allen 1976; Popper 1980;
Schmidt-Kaler
1982). According to Dr. Morgan (in Sahade & Cesco 1945) the secondary
component is a star of near F0 spectral type.
As already stated in Sects. 1 and 2, the observed spectral type of the
primary component is B5. According to Dr. Morgan (in Sahade & Cesco 1945)
the intensity of H lines in this component was of the same order as in a B5IV
star. When compared to a main sequence B5 star, the derived radius of the
primary component is larger by about 35%, its log g value (3.76) lies in
between the log g values for a B5V (4.04) and B5III (3.49) stars
(Schmidt-Kaler
1982) and it has already filled about 25% of its Roche lobe
(
=0.534;
Plavec
& Kratochvil 1964). All these properties indicate a slight evolution of the
primary component and confirm its classification to be B5IV. Hence AU Mon
consists of B5IV plus F9-G0III-II stars as its components.
As the difference in the absolute visual magnitudes 
of the secondary and
primary components is 1.38 (Table 3 (click here)), the ratio of their luminosities 
is
equal to 0.28. From this ratio, one can calculate the combined visual absolute
magnitude of AU Mon to be -2.04. The apparent visual magnitude 
at
maximum of AU Mon was recorded as 8.5 (Batten 1967) and 8.3
(Wood et al. 1980).
Taking an average of these values, along with the combined 
and assuming no
space reddening the distance modulus (m-M) of AU Mon is derived as 10.44, from
which a distance of 
pc is obtained. However, Peters (1994) suggested a
reddening of 
for this system. If this were the case, space
absorption 
equals 
(Allen 1976), from which a distance of 
pc
is obtained for AU Mon.
For a comparison, the system parameters, as reported by Lorenzi (1982) and
Giuricin et al. (1982) along with those obtained from the present analysis
are given in Table 4 (click here).
| Parameter | Lorenzi | Giuricin | Present |
| (1982) | et al. (1982) | studies | |
| Method | 1 | 2 | 3 |
 K | 15500* | 15000* | 15500* |
 K | 5300 | 6600 | 6000 |
| q | - | 0.2* | 0.1985 |
 | 82.0 | 78.4 | 78.74 |
 | 0.93 | 0.645 | 0.659 |
 | 0.07 | 0.355 | 0.341 |
| l3 | - | - | 0.0 |
 | 0.18 | 0.115 | 0.131+ |
 | 0.18 | 0.242 | 0.249+ |
 | - | 2.98 | 3.16 |
 | - | 2.20 | 2.07 |
 | 6.5* | 6.0* | 5.93 |
 | 1.4 | 1.2 | 1.18 |
 | 7.5 | 4.6 | 5.28 |
 | 7.5 | 9.7 | 10.04 |
| Sp.typ (Pri) | B5V | B5V | B5IV |
| Sp.typ (Sec) | - | early F | F9-G0III-II |
Method:
Russell-Merrill Wood's WINK Wilson-Devinney.