COMMISSION 27 OF THE I. A. U.
             INFORMATION BULLETIN ON VARIABLE STARS
                          Number 924

                                       Konkoly Observatory
                                       Budapest
                                       1974 September 14


    OBSERVATIONS OF THE CARBON STAR V493 MONOCEROTIS

    The object V493 Mon (Maffei 1966) has recently been identified
as an extremely red [ (B-V) > 6.0 ] carbon star (Kalinowski, Burkhead
and Honeycutt 1974). The possibility exists that V493 Mon, located
approximately 2.5 minutes of arc from the center of the old open cluster 
Trumpler 5 Kalinowski 1975, is a lightly evolved, low mass cluster 
member (M < 1.4 M_{sun}). Observations which would aid in determining the
star's variability class may help settle the question of cluster 
membership.
    A program to monitor V493 Mon's variability photoelectrically
in V, R and I will begin this fall at Indiana University. Supplementary
observations by other interested observers would be appreciated. The
star's coordinates are alpha=6h35m10s.2, delta=+9deg26'56" (1975.0). Previous
photoelectric measures, in March, 1974, yielded V = 13.6, V-R = 3.8,
and V-I = 5.6. Sparse (and preliminary) photographic data reveal a
variation in V between 13.5 and 14.8.
    Interested participants are requested to contact me, relating
the specifics of their observations, at the address given below. I can
supply a limited number of finding charts to observers planning programs. 
The field around V493 Mon is very crowded (contamination on
small scale plates prevented Maffei from discerning the star's highly
unusual nature) and investigators are cautioned that the previously
published declination (Epoch 1900.0) for the star is in error by 
approximately 2 minutes of arc.


September 3, 1974
                                            J. KEITH KALINOWSKI
                                            Astronomy Department
                                            Indiana University
                                            319 Swain Hall West
                                            Bloomington, Indiana,
                                            47401. U. S. A.
References:

Kalinowski, J.K., Burkhead, M.S. and Honeycutt, R.K. 1974, Ap.J.
            Letters, 193, in press. [BIBCODE 1974ApJ...193L..77K ]
Kalinowski, J.K., 1975, Ph.D. Thesis, Indiana University, in 
            preparation.
Maffei, P. 1966, Memorie della societa Astronomica Italiana, 37,475. [BIBCODE 1966MmSAI..37..475M ]