COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                       Number 2796

                                        Konkoly Observatory
                                        Budapest
                                        23 September 1985

                                        HU ISSN 0374 - 0676


           THE ABSOLUTE MAGNITUDE OF THE FLARE STAR
                    AZ CANCRI (LHS2034).



    AZ Cancri (LP425-140, LHS2034, G1316.1 Y2067.01); listed as a flare
star by Haro and Chavira (1966), was discussed as a possible very low 
luminosity M dwarf by Bidelman and Hoffleit (1983). On the basis of a trigonometric
parallax (0.139") determined by Luyten (1965) from 21 Palomar Schmidt plates,
the estimated Mpg would make the star one of the intrinsically faintest known.
We report three kinds of new observational data which provide a much more
accurate absolute magnitude estimate for this star.
  First, a preliminary U.S. Naval Observatory trigonometric parallax of
0.0608" +/- 0.0067" (m.e.) is in conflict with the earlier value. Secondly, a
single photometric measurement with the USNO 1.5 meter reflector gives
V = 17.68, B-V = 2.02, V-I = 4.34 with I on the Kron-Mayall system. These
yield an absolute visual magnitude Mv = 16.60 +/- 0.24, and suggest that the
star may be about 0.5 magnitude above the mean Mv, V-I main sequence for old
disk stars (Pesch and Dahn 1982). Finally, two excellent red CCD spectra
obtained with the KPNO Mayall 4 meter telescope and cryogenic camera in 1984
permit the object to be classified as M6.5Ve, in agreement with the parallax
and colors. Spectra and VRI colors reported in Hartwick et al. (1984) are
consistent with the above conclusions. Strong hydrogen line emission was
present in our CCD spectra. The estimated tangential velocity is 71 km/s. The
above results are consistent with the star being either (1) a young object
approaching the main sequence, or (2) an unresolved double, where the
contributions to the visual light of both components account for the Mv value
being overluminous and possibly for the vigorous flaring activity.

  We thank Dr. H.E. Bond for suggesting that we obtain the KPNO CCD spectra
of this star.




                     C. DAHN
                     U.S. Naval Observatory, Flagstaff,
                     AZ 86001


                    R. GREEN and W. KEEL
                    Kitt Peak National Observatory
                    Box 26732
                    Tucson AZ 85726

                    D. HAMILTON
                    Cerro Tololo Interamerican Observatory
                    Casilla 63-D, La Serena,
                    Chile 1353

                    V. KALLARAKAL
                    U.S. Naval Observatory,
                    Washington, D.C. 20390


                    J. LIEBERT
                    Steward Observatory
                    Univ. Arizona
                    Tucson AZ 85721



References:
Bidelman, W.P., and Hoffleit, D. 1983, IBVS No. 2414. 
Haro, G, and Chavira, E., 1966, Vistas in Astr. 8, 89. [BIBCODE 1966VA......8...89H ]
Hartwick, F.D.A., Cowley, A.P., and Mould, J.R., 1984, Ap.J. 286, 269. [BIBCODE 1984ApJ...286..269H ]
Luyten, W.J., 1965, Publ.Univ.Minn. 3, No. 16. [BIBCODE 1965POMin..16....1L ]
Pesch, P., and Dahn, C.C., 1982, Astron.J. 87, 122. [BIBCODE 1982AJ.....87..122P ]