Alard (1996) demonstrated that the faint peak in
a bimodal distribution of the RR Lyrae stars
of Bailey type ab is due to a contribution from
the Sagittarius dwarf galaxy. Application of this method
to the PG3 RR Lyrae stars gives 12 variables of Bailey type ab
(hereafter referred to as RRab and RRc
for Bailey type c)
and 4 RRc stars. Figure 1 (click here) shows the distance modulus distribution
from which the RRab stars were selected.
Following Wesselink (1987) we adopted for the absolute magnitude of
the RRab: 
and 
.
The difference in the distribution between the two passbands is
due to extinction. From Fig. 1 (click here) we obtain for PG3 a mean colour
excess
.
The stars with distance modulus larger than 
are selected as possible
members of the Sagittarius dwarf galaxy. The RRc candidates are
selected in a similar way, straight from their magnitude distribution.
This method cannot be applied to select the long period variables
in the visual passbands, because of their large amplitudes.
In the near-infrared passbands the amplitude of their
variations is significantly smaller.
From the K-magnitude distribution (Paper II, Fig. 2 (click here)) 1 Mira and
5 semiregular variables are thus selected.
The actual number of stars might be even larger, because we do
not have near-IR photometry for all PG3 long period variables.
Table 1 lists the whole catalogue of PG3 variables which are possibly
located in the Sagittarius dwarf galaxy. The finding charts
(
; north is at the top and east is to the left) are only
available in electronic form at the CDS. The identification
of the stars was made by Wesselink (1987).
Figure 1: Distance modulus distribution of the
RR Lyrae stars Bailey type ab
in PG3 (data from Wesselink 1987, see text for
additional details).
The solid line shows the distribution obtained from the 
-magnitudes
and the dotted distribution is obtained from the 
-magnitudes