COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1650 Konkoly Observatory Budapest 1979 July 31 A NEW LATE TYPE VARIABLE WITH H AND K EMISSION An obvious source of candidates for variable G and K type giants and subgiants with H and K emission is the Michigan Spectral Type Catalogue (vols. I and II) which covers the sky from -90d to -40d. The first star selected from this catalogue for photometric monitoring was HD 83442, which is classified K2 IIIp ("Ca H and K cores are quite strongly in emission"). The observations on a modified Stromgren system are listed in Table 1 and a few on the (RI) system are in Table 2. Figure 1 shows the variations in V, b-y and R. The total range in near 0.3 mag in V and appears to be quasiperiodic with P = 65 to 70 days. The minima are relatively narrow, judging by the last observations shown in the figure (June 1979). The color is reddened at minima by only one or, two hundredths in both (b-y) and (R-I). Early type stars in the region indicate a reddening of only about E(b-y) = 0.02 mag at a distance modulus of 8.5 mag in this direction. If we adopt a reddening of 0.02 mag, the values of (R-I) and M_1 indicate a near solar metal abundance. The mean value of C_1 = 0.340 mag indicates a lower luminosity than that given by the spectral luminosity class but this possibly is reflecting some spectral abnormality (e.g., CH or BaII). Nearly identical values of the proper motion are [FIGURE 1] given in the Cape and Yale Zone catalogues; the mean values on the FK4 system with precessional corrections are (mu alpha . mu delta) = (-0.063", 0.000"). The star is also BPM 34343 with a relative proper motion of 0.052" in position angle 300d. If the luminosity is near M_V = 0, (U, V, W) = ( + 140, -14 + rho, -126) km/sec; the unknown radial velocity is essentially a measure of the V velocity only. These velocity vectors indicate a halo object, but if we lower the assumed luminosity to M_V = +2 mag, which would be more in accordance with the value of C_1, the vectors become (+56, -6+rho, -50) km/sec. OLIN J. EGGEN Cerro Tololo Inter-American Observatory^1 Casilla 63-D La Serena, Chile 1 Cerro Tololo Inter-American Observatory is supported by the National Science Foundation under contract No. AST 78-27879. TABLE 1 Observations of HD 83442 -------------------------------------------------------------- JD244 V b-y M_1 C_1 (u-b) -------------------------------------------------------------- 3886.542 8.99m 0.740m 0.482m 0.298m 2.721m 3911.562 9.06 0.743 0.504 0.322 2.799 3920.587 8.89 0.712 0.479 0.355 2.719 3938.656 8.88 0.734 0.478 0.348 2.750 3939.760 8.88 0.723 0.492 0.369 2.751 3940.750 (8.83) 0.732 0.476 0.369 2.762 3941.750 8.91 0.728 0.485 0.358 2.764 3942.615 8.92 0.720 0.508 0.311 2.752 3977.635 9.06 0.721 0.500 0.351 2.777 3997.543 8.84 0.724 0.482 0.336 2.728 4023.545 9.03 0.740 0.487 0.337 2.769 4024.521 9.03 0.742 0.484 0.329 2.759 4032.503 9.12 0.746 0.485 0.340 2.780 4035.476 9.13 0.758 0.468 0.344 2.770 4036.493 9.13 0.752 0.483 0.350 2.798 4037.465 9.13 0.745 0.494 0.326 2.785 4048.458 8.96 0.738 0.470 0.332 2.724 -------------------------------------------------------------- TABLE 2 (RI) Observations ------------------------------ 1979 R R-I ------------------------------ 21 Feb. 8.28m +0.392m 2 Mar. 8.28 +0.398 3 Mar. 8.27 +0.406 4 Mar. 8.26 +0.395 5 Mar. 8.32 +0.416 21 Apr. 8.34 +0.412 15 June 8.49 +0.427 16 June 8.49 +0.423 17 June 8.47 +0.425 ------------------------------