COMMISSION 27 OF THE I. A. U.
               INFORMATION BULLETIN ON VARIABLE STARS
                            Number 3490

                                                       Konkoly Observatory
                                                       Budapest
                                                       10 July 1990

                                                       HU ISSN 0374 - 0676


             PHOTOELECTRIC PHOTOMETRY OF RHO CASSIOPEIAE

  This paper represents a continuation of previous photoelectric work done on the
variable star rho Cassiopeiae (Leiker, et al.,1989,1988,1987). rho Cassiopeiae (rho Cas, HR
9045, HD 224014, SAO 035879) is a supergiant (F8pIA) star (Percy & Keith,1985). It
was discovered to be a variable in 1900 by Louise D. Wells (Pickering 1901). Much of the
time this star was confined to a brightness between 4.1m and 5.1m (Bailey, 1978).
However, between August 1945 and June 1947 rho Cas decreased in brightness more than a
magnitude (Gaposchkin,1949). After it recovered from this minimum, rho Cas continued its
irregular variation in brightness between 4.1m and 5.1m.
  Rho Cas was observed by Leiker and Hoff at the University of Northern Iowa's Hillside
Observatory from June 1989 through February 1990. A 0.4 meter Cassegrain telescope
and a STARLIGHT-1 photon counting photometer with standard B and V filters was used.
HR 9010 (HD 223173, SAO 35761, K3 II, V = 5.51 m, B-V = 1.65) was used as the
comparison star. These delta magnitudes are not corrected for color or extinction.
Standard deviation (a) was calculated in the usual manner. Table 1 lists the DeltaV and DeltaB
magnitudes. Figures 1 and 2 are graphical representations of the data presented in Table 1.

This work was supported in part by a computer equipment grant from a Theodore Dunham, Jr.
Grant of the Fund for Astrophysical Research.

Table I. DeltaV and DeltaB magnitudes of rho Cas obtained by Leiker and Hoff

HJD         DeltaVmean sigma   #   HJD         DeltaBmag  sigma   #
2447703.678   -0.981   0.051   3
2447771.616   -0.902   0.006   3
2447803.628   -0.866   0.004   3   2447803.643   -1.078   0.002   3
2447819.611   -0.847   0.005   3   2447819.625   -1.077   0.002   3
2447823.646   -0.846   0.008   3   2447823.664   -1.065   0.002   3
2447833.687   -0.843   0.003   3
2447839.690   -0.830   0.005   3
2447844.542   -0.829   0.001   3   2447844.558   -1.056   0.004   3
2447850.521   -0.842   0.006   3   2447850.536   -1.096   0.001   3
2447854.535   -0.857   0.005   3   2447854.551   -1.111   0.003   3
2447860.669   -0.852   0.004   3   2447860.682   -1.118   0.007   3
2447864.605   -0.855   0.005   3
2447872.602   -0.850   0.006   3   2447872.618   -1.105   0.007   3
2447893.624   -0.888   0.001   3   2447893.636   -1.175   0.007   3
2447897.597   -0.875           1
2447904.530   -0.920   0.005   3   2447904.548   -1.207   0.009   3
2447906.589   -0.921   0.003   3   2447906.595   -1.211   0.007   3
2447922.536   -0.940   0.001   3
2447928.528   -0.959   0.009   3


                               [FIGURE 1]

       Figure 1. DeltaV magnitudes of rho Cas obtained by Leiker and Hoff

                               [FIGURE 2]

       Figure 2. DeltaB magnitudes of rho Cas obtained by Leiker and Hoff



P. STEVEN LEIKER and DARREL B. HOFF
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, MS 71 Cambridge, MA 02138
USA



References:
Bailey, J.: 1978, Journal of the British Astron. Association 88, (4), 397-401. [BIBCODE 1978JBAA...88..397B ]
Gaposchkin, S.: 1949, Harvard College Obs. Bull. No.919, 18-19. [BIBCODE 1949BHarO.919...18G ]
Leiker, P.S., Hoff, D.B., Milton, R.: 1989, IBVS No. 3345.
Leiker, P.S., Hoff, D.B., Nesbella, J., Gainer, M., Milton, R., Pray, D.:
  1988, IBVS No. 3172.
Leiker, P.S., Hoff, D.B.: 1987, IBVS No. 3020.
Percy, J.R., Keith, D.W.: 1985, Cepheids: Theory and Observations (ed. B.F.
  Madore), University of Cambridge Press, pp.89-90. [BIBCODE 1985cto..conf...89P ]
Pickering, E.C.: 1901, Harvard College Obs. Circular No.54. [BIBCODE 1901HarCi..54....1P ]