starsCYG             package:robustbase             R Documentation

_H_e_r_t_z_s_p_r_u_n_g-_R_u_s_s_e_l_l _D_i_a_g_r_a_m _D_a_t_a _o_f _S_t_a_r _C_l_u_s_t_e_r _C_Y_G _O_B_1

_D_e_s_c_r_i_p_t_i_o_n:

     Data for the Hertzsprung-Russell Diagram of the Star Cluster CYG
     OB1, which contains 47 stars in the direction of Cygnus, from
     C.Doom.  The first variable is the logarithm of the effective
     temperature at the surface of the star (Te) and the second one is
     the logarithm of its light intencity (L/L_0).

     In the Hertzsprung-Russell diagram, which is the scatterplot of
     these data points, where the log temperature is plotted from left
     to right, two groups of points are seen:
      the majority which tend to follow a steep band and four stars in
     the upper corner.  In the astronomy the 43 stars are said to lie
     on the main sequence and the four remaining stars are called
     "giants" (the points 11, 20, 30, 34).

_U_s_a_g_e:

     data(starsCYG)

_F_o_r_m_a_t:

     A data frame with 47 observations on the following 2 variables

     '_l_o_g._T_e' Logarithm of the effective temperature at the surface of
          the star (Te).

     '_l_o_g._l_i_g_h_t' Logarithm of its light intencity (L/L_0)

_S_o_u_r_c_e:

     P. J. Rousseeuw and A. M. Leroy (1987) _Robust Regression and
     Outlier Detection_; Wiley, p.27, table 3.

_E_x_a_m_p_l_e_s:

     data(starsCYG)
     plot(starsCYG)
     cst <- covMcd(starsCYG)
     lm.stars <- lm(log.light ~ log.Te, data = starsCYG)
     summary(lm.stars)
     plot(lm.stars)
     lts.stars <- ltsReg(log.light ~ log.Te, data = starsCYG)
     plot(lts.stars)

