COMMISSION 27 AND 42 OF THE IAU
                   INFORMATION BULLETIN ON VARIABLE STARS
                               Number 3843

                                                         Konkoly Observatory
                                                         Budapest
                                                         12 February 1993

                                                         HU ISSN 0374 - 0676


                     A NEW VARIABLE IN SAGITTARIUS

Estimating the photographic infrared magnitude (m_I) of the long period
variable V3935 Sgr, a new variable star was discovered. The provisional name
of the variable is M313, following the progressive numerations adopted by
Maffei (1975). The position is: alpha(1950.0)=18h21m26s; delta(1950)=-17d04'25".
Figure 1 shows the infrared finding chart and the comparison stars.


                           [FIGURE 1]

                     Figure 1. Finding chart

                           [FIGURE 2]

               Figure 2. The light curve of the new variable


                           Table I

JD (24....)    m_I      JD (24....)    m_I      JD (24....)    m_I

37529.40610   <15.2     37544.32360   <15.2     37549.34880   <15.2
37552.33540   <15.2     37578.30590    15.1     37583.30260    15.0
37870.40210    15.1     37880.43510   <14.0     37883.41170    15.3
37940.27980    14.8     37942.27820    14.7     39681.44020    16.1
39699.39910   <15.2     39701.39690   <15.8     39703.36910    16.1
39739.33840    16.2     39759.27980    16.1     39767.27900   <15.8
40042.48760   <15.8     40043.36550   <15.8     40053.36270   <15.8
40057.38290   <15.8     40058.42530   <15.8     40060.49180   <15.8
40124.31040    15.7     40153.24120   <15.8     40362.60070    15.1
40364.57780    15.3     40415.49570    14.6     40417.48050    14.7
40448.50000    14.7     40508.25170   <15.2     40765.46610    15.9
40778.39790    16.0     40780.44500    15.9     40799.34980    15.9
40801.34480   <15.8     40803.33560   <15.8     40805.39580    16.1
40809.35940   <15.8     40821.40790   <15.2     40824.32120    16.1
41068.62440   <15.2     41093.54590   <15.8     41129.49250   <15.8
41143.37700   <14.0     41160.34630   <15.2     41162.37620   <15.8
41163.35470   <15.8     41177.32590   <15.8     41181.37130    15.5
41213.30760    15.4     41215.29690    15.4     41244.25820    14.8
42663.40020    14.7     42688.25690    15.5     42691.24750    15.5
44491.34640   <14.0     44494.36070    15.3     44495.38980    15.0
44496.33970    14.7     45612.25750    14.8     45612.31660    14.8
45616.31230   <14.5     45635.22870    14.9     48041.53150   <15.2
48068.53230   <15.2     48093.41680   <15.2     48180.29570   <15.2
48471.34470    14.6     48481.42310    15.0     48496.34630    14.7
48497.40030   <15.2     48498.33770    15.1     48509.39300    15.2
48516.31310   <14.5     48527.33850   <15.2     48540.25690   <15.2
48565.22270   <14.0

  The photographic infrared plates (I-N(hypers.)+RG5) were taken with the:
  -40/50 cm Schmidt telescope at the Asiago Observatory (12 plates the in years
1961, 1962, plus one in 1969);
  -65/90 cm Schmidt telescope at the Asiago Observatory (58 plates in the years
1967, 1971, 1975, 1990);
  -40/60 cm Schmidt telescope at the Catania Astrophysical Observatory (78
plates in the years 1980, 1983, 1991).
   The star M313 is in the field only 79 of all the plates obtained. The
estimated m_I shows that the star varies over the observed range of 1.5
magnitudes. The m_I light curve is drawn in Figure 2 (the down arrows indicate
when the magnitude of the star is below the limit of the plate). Table I
details the values. Search for periodicity was performed with Deeming's method
(1975) but no period is supported by a phase diagram. Therefore, at present,
the variability type of M313 remains unknown.


                                            Gino TOSTI
                                            Osservatorio Astronomico
                                            Universita di Perugia,
                                            06100 Perugia, Italia



References:

Deeming, T.J., 1975, Astrophys. Space Sci., 36, 137. [BIBCODE 1975Ap&SS..36..137D ]
Maffei, P., 1975, IBVS, No. 985.