COMMISSIONS 27 AND 42 OF THE IAU
                INFORMATION BULLETIN ON VARIABLE STARS
                             Number 4089

                                                      Konkoly Observatory
                                                      Budapest
                                                      19 September 1994

                                                      HU ISSN 0374 - 0676


          NEW PHOTOELECTRIC OBSERVATIONS AND PERIOD OF RS LEPORIS

  The first photoelectric observations of the eclipsing system RS Lep (BD-20d1245)
were made by Wood (1959). Over the years, Klepczynski and Wood (1964) determined
the improved light elements by means of the available published minimum times. The
present observations were carried out with the single channel photoelectric photometer in
BV bands at Yunnan Observatory. The 60cm reflecting telescope was employed on three
nights in December 1993 and the 100cm reflecting telescope was employed on the three
nights in February 1994. The star BD-20d1244 and the star BD-20d1253 were used as
the comparison star and check star, respectively. From our observations 286 points in B
and 290 points in V shown in Figures 1 and 2 were obtained. From these data moments
of two primary minima were determined which are included in Table 1.
  The new observations show a different amplitude for the primary minimum from that
determined by the previous observer, the present depths of primary minimum are about
1.7m in B band and about 1.6m in V band, while those of the previous observer are about
1.6m in B band and about 1.4m in V band. All available minimum times were introduced
into a least squares solution to derive the new light elements:

           Min. I = JD(Hel.)2427386.5282 + 1.28854391d x E
                                   +/-22        +/-19


                             [FIGURE 1]

        Figure 1. The blue individual observations of RS Lep.

                             [FIGURE 2]

        Figure 2. The yellow individual observations of RS Lep.

                             [FIGURE 3]

                     Figure 3. The O-C diagram


	Table 1. Minimum times of RS Lep

JD.(Hel.)      Cycle     O-C   Weight   Source
2426596.6090    -613   -0.0418   1        S
2426604.3700    -607   -0.0121   1        Z
2427386.5250       0   -0.0032   3        S
2427390.3890       3   -0.0048   3        Z
2427438.0660      40   -0.0040   3        S
2427443.2260      44    0.0019   3        S
2427443.2270      44    0.0029   3        Z
2427461.2630      58   -0.0008   3        S
2427461.2640      58    0.0002   3        Z
2428091.3620     547    0.0003   3        G
2431163.2390    2931   -0.0114   3        Z
2432235.3150    3763   -0.0039   3        S
2432409.2690    3898   -0.0034   3        S
2436191.1520    6833    0.0033   30       W
2436204.0375    6843    0.0033   30       W
2440207.5510    9950    0.0109   1        F
2449334.2981   17033    0.0015   30       This paper
2449396.1426   17081   -0.0041   30       This paper

 S=Soloviev, Z=Zessevich, G=Gaposchkin, W=Wood, F=Flin

 In our calculation weight 1 was assigned to the visual minimum times, weight 3 to the
photoelectric minimum times and weight 30 to the photoelectric ones.

 Using this new formula we have calculated the O-C values listed in Table 1 and plotted
the O-C diagram displayed in Figure 3. From the O-C diagram it is seen that the period
of RS Lep does not vary. Further observations of the system will be made during the next
observing season and the final analysis and discussion will be published elsewhere.


                           GU SHENGHONG
                           LIU QUINGYAO
                           YANG YULAN
                           WANG BI
                           HUANG ZHANKUI
                           Yunnan Observatory
                           Chinese Academy of Sciences
                           Kunming
                           P. R. of China


References:

Flin, P, 1969, IBVS, No. 328
Gaposchkin, S., 1953, Harvard Ann., 113, (2) [BIBCODE 1953AnHar.113...67G ]
Klepczynski, W. J. and Wood, F. B., 1964, Astron. J., 69, 92 [BIBCODE 1964AJ.....69...92K ]
Soloviev, A., 1938, Nishni-Novgorod Var. Stars, 5, 174
Soloviev, A. 1947, Kazan Astron. Circ., 61, 8
Wood, F. B., 1959, Astron. J., 64, 56 [BIBCODE 1959AJ.....64S..56W ]
Zessevich, V. P., 1943, Kazan Astron. Circ., 18, 5
Zessevich, V. P., 1954, Odessa Izv., IV (2), 189