Abnormal color-color diagram of R1 saturated stars

                                             C.X. 10.3.2001

During QA, Davy found an abnormal color-color diagram of R1 saturated stars in 981023s:

Gene and I looked into the two worst cases on this plot,
which are the two green spots that represent two
stars saturated in H. The most relevant data about these
stars can be summarized in the following table:

|scan| name        |type| V    |  g_lat      | J_2m| H_2m| K_2m|see_sh|
 029  HD202034  K2   7.27  -34.4341  4.898   3.631   4.035  1.13
 041  HD10957    K2   8.60  -66.6088  4.776   3.193   3.685  1.15

Here are what we found:

1) They are in the high-g_lat/low-density regions.
2) The J-K colors of them are reasonable given their types (K2).
3) They have too red J-H (1.2 and 1.6, respectively) and too blue
    H-K (-0.4 and -0.5, respectively).
4) It most likely that the magnitudes of the H band, the single
    band at which these stars are saturated, are too bright, rather than
    the J and K band magnitudes are simultaneously too faint.
5) Given that for both stars the seeing is rather bad, it is likely that the
    over-estimates of the H band brightness are due to the seeing effect.
6) Using the seeing correction formula given here
    I got a correction of 0.48 for the H mag of HD202034 and 0.57
    for the H mag of HD10957. After the seeing correction,
    these stars have J-H of 0.78 and 1.01, respectively,
    and H-K of 0.08 and 0.08, respectively. These colors fit well into the
    color-color diagram.

Conclusion: The anomaly is due to the seeing effect. After the seeing
correction, which is prescribed in my website, the colors of these stars look OK.