COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                       Number 2876

                                          Konkoly Observatory
                                          Budapest
                                          13 March 1986

                                          HU ISSN 0374 - 0676



          PHOTOMETRIC BEHAVIOR OF HR8752 =V 509 Cas II.



   The highly luminous supergiant V509 Cas is known to be moderately variable
in both spectrum and magnitude. Observed spectral types have ranged from late
F to K2-5 Ia (Lambert and Luck, 1978). The V magnitude range has been observed
to be approximately +4.6 to +5.4 while (B-V) colors have ranged from +1.3 to
+1.7 (Walker, 1983 and Luck, 1975). The star is probably binary with a B1V
companion but the suggested period of 4 years (Stickland and Harmer, 1978)
does not correlate with the photometric behavior which remains non-periodic
and of unknown type.
V 509 Cas was observed in B and V magnitudes on 23 nights from September,
1985 to January, 1986 with the 0.6-m telescope of the Corralitos Observatory
and its automated single channel photon-counting photometer and uncooled EMI
9924A photomultiplier tube.The observations utilized the same comparison
stars as the previous season (reported in Paper I, Halbedel, 1985): HR 8761
(V= 6.20; B-V= +1.50) and HR 8778(V= 6.43; B-V= +0.90). Extinction and
transformations to BV magnitudes were accomplished by observations of standard
stars. No changes larger than +-0.01 magnitudes were evident in the measurements
of the standard stars either night-to-night or season-to-season.

               Table   I

 JD                      JD
(2440000+)  V  (B-V)   (2440000+)  V   (B-V)

6329.7520 4.79 +1.24    6377.7006 4.83 +1.28
6331.7743 4.82          6391.6520 4.87  1.29
6333.7076 4.79  1.23    6392.6479 4.87  1.29
6334.7784 4.79  1.24    6409.6618 4.87  1.31
6335.7500 4.78  1.25    6410.5604 4.86  1.29
6347.7437 4.78  1.25    6427.5666 4.94  1.33
6350.7854 4.79  1.24    6428.5715 4.94  1.32
6351.8020 4.79  1.26    6432.5694 4.94  1.31
6352.7944 4.80  1.25    6449.5736 4.99  1.36
6353.7458 4.79  1.27    6450.5749 4.96  1.35
6357.6881 4.81  1.27    6455.5687 4.97  1.38
6376.7076 4.87  1.26



                             [FIGURE 1]

 Figure 1. Variations in V and B-V magnitudes for HR 8752 = V 509 Cas


  Table I shows the magnitudes obtained and Figure 1 the variations as
compared to those from Paper 1. It may be seen that V509 Cas became slightly
brighter and bluer in the second observing season and declined in magnitude
rather more rapidly. A period of approximately a year is suggested although
past photometric behavior indicates that this will not persist for very long.
  Special thanks are rendered to B. Goodrich for the automation of the
photometric system.



                              E.M. HALBEDEL
                           Corralitos Observatory
                           P.O. Box 16314
                           Las Cruces, NM 88004
                           USA



References: 
Halbedel, E.M., 1985, Inf. Bull. Var. Stars, No. 2718.
Lambert, D.L., and Luck, R.E., 1978, Mon. Not. Roy. Astr. Soc., 184, 405. [BIBCODE 1978MNRAS.184..405L ]
Luck, R.E., 1975, Astrophys. J., 202, 743.  [BIBCODE 1975ApJ...202..743L ]
Stickland, D.J., and Harmer, D.L., 1978, Astron. Astrophys., 70, L53.  [BIBCODE 1978A&A....70L..53S ]
Walker, E.N., 1983, Mon. Not. Roy. Astr. Soc., 203, 403.  [BIBCODE 1983MNRAS.203..403W ]