| Abstract | In the Letter "The Distance to the Large Magellanic Cloud from SN 1987A" by Marshall L. McCall (ApJ, 417, L75 [1993]), a sign error was made which affects the direction (but not the size or uncertainty) of the correction required to compute the distance modulus of the center of mass of the Large Magellanic Cloud from the distance to SN 1987A. Equation (1) was derived on the basis of a sign convention which requires that the inclination of a disk be negative if the near side is located at position angles less than that of the line of nodes (for which the position angle is defined to lie between 0^deg^ and 180^deg^), as is the case for the LMC (J. A. R. Caldwell & I. M. Coulson, MNRAS, 218,223 [1986]). With i = - 28.5^deg^ +/- 4^deg^, then, the first coefficient of equation (7) is raised to 1.0122 +/- 0.0021, so that d_c_/d_SN_ = 1.012 +/- 0.016 if the supernova is allowed to be located anywhere within the layer confining 99% of the light of the young disk. Consequently, the center of mass of the LMC must be 0.03 +/- 0.03 mag farther from the Sun than SN 1987A, rather than nearer as stated in the Letter. The "1 σ" uncertainty (defined by the layer containing 68% of the light) is only 0.01. Based upon the analysis of the circumstellar ring by Panagia et al. (ApJ, 380, L23 [1991]), the heliocentric distance to the LMC is 51.8 +/- 3.2 kpc, which corresponds to a distance modulus of 18.57 +/- 0.13. However, readers should be aware that more refined analyses with improved ring parameters (e.g., from P. Plait, P. Lundqvist, R. Chevalier, & R. P. Kirshner, Univ. Virginia preprint [1994]) are now indicating a shorter
distance (T. Schmidt-Kaler, in New Aspects of Magellanic Cloud Research, ed. B. Baschek, G. Klare, & J. Lequeux [Berlin: SpringerVerlag], 24 [1993]; A. Gould, private communication [1994]). |
