COMMISSION 27 AND 42 OF THE IAU
                   INFORMATION BULLETIN ON VARIABLE STARS
                               Number 3849

                                                         Konkoly Observatory
                                                         Budapest
                                                         26 February 1993

                                                         HU ISSN 0374 - 0676


              RECENT UBVR MAGNITUDES FOR HR 8752=V509 Cas

The hypergiant HR 8752 has been observed over the past nine observing seasons
at the Corralitos Observatory. Most of this data has been previously published
(Halbedel, 1985, 1986, 1988, 1991). This paper reports on the most recent UBVR
data which has been acquired.
   A well-known spectrum and photometric variable, HR 8752 has a long
publication history whose most recent entry is by Sheffer & Lambert (1992) who
have found interesting correlations between [N II] strength and continuum
intensity, showing possible cyclical behavior for the continuum with a >=30
year period. On a shorter time-scale, the star varies semi-regularly with
periods around 400 days (Arellano Ferro, 1985; Sheffer & Lambert, 1987). Its
most recent photometric behavior has been characterized by a trend of fading
and bluing with more rapid changes superimposed.
   HR 8752 has been observed photometrically with the 0.6-m. telescope of the
Corralitos Observatory. Two photometric systems were utilized, the first based
on an EMI 9924A tube and the second on an R4457. All U and R magnitudes were
obtained with the second system. Two comparison stars were utilized: HR 8761
(V=6.200; B-V=+1.500; U-B=+1.530; V-R=+1.088) and HR 8778 (V=6.430; B-V=
+.900; U-B=+.538; V-R=+.767).  Over the time period of observation, these two
stars were stable to within 0.015, 0.014, 0.015 and 0.017 in V, B-V, U-B and
V-R respectively.
   The most recent UBVR magnitudes obtained for HR 8752 are shown in Figure 1
and appear in Table 1. It may be seen that the trend towards fading and bluing
is still continuing. There are too few U-B and V-R magnitudes to ascribe a
trend as of yet.
   HR 8752 will continue to be observed at the Corralitos Observatory
indefinitely into the future.

  The author would like to most gratefully acknowledge a Theodor Dunham, Jr.
grant of the Fund for Astrophysical Research for purchase of photometric
equipment.


                              [FIGURE 1]

 Figure 1. Magnitudes and colors for HR 8752. The top diagram shows V, 
 the bottom B-V. Julian Date is JD-2440000.


                     Table 1
              UBVR magnitudes for HR 8752
            Numbers following magnitudes in
       parentheses are standard errors in millimags.

Julian Date     V(SE)        B-V(SE)     U-B(SE)     V-R(SE)
(2440000+)

8414.93125     5.078(21)   +1.070(4)
8532.77083     5.095(-)     1.066(5)
8535.73750     5.103(-)     1.057(7)
8546.69514     5.128(15)    1.051(6)
8562.68194     5.104(12)    1.044(1)
8597.66040     5.064(-      1.047(8)
8620.58264     5.080(-)     1.033(17)
8636.58681     5.089(-)     1.073(13)
8637.58958     5.075-)      1.086(15)
8732.94583     5.042(18)    1.000(3)
8800.92778     5.001(24)    0.983(4)   +.682(10)   +.887(3)
8842.87431     5.024(-)
8898.74931     5.152(23)    0.999(2)    .744(11)    .905(8)
8901.72639     5.155(18)    1.012(1)    .719(16)    .925(4)
8932.74028     5.124(32)    1.068(26)   .718(6)     .878(19)
8933.70000     5.133(22)    1.053(1)    .736(2)     .871(13)
8951.68958     5.156(-)     1.030(12)   .745(4)     .883(8)



                                          ELAINE M. HALBEDEL
                                          Corralitos Observatory
                                          P.O. Box 16314
                                          Las Cruces, NM
                                          U.S.A. 88004



References:

Arellano Ferro, A., 1985, MNRAS, 216, 571. [BIBCODE 1985MNRAS.216..571A ]
Halbedel, E. M., 1985, IBVS No. 2718.
                 1986, IBVS No. 2876.
                 1988, IBVS No. 3170.
                 1991, IBVS No. 3600.
Sheffer, Y. & Lambert, D.L., 1987, PASP, 99, 1277. [BIBCODE 1987PASP...99.1277S ]
                             1992, PASP, 104, 1054. [BIBCODE 1992PASP..104.1054S ]