Abstract: Observations of 314 stars with the uvbyß photometric system are used to establish the reddening in the direction of the nearby Triangulum galaxy M33. Color excesses are obtained for 151 A and F type stars in a 1° radius centered around the galaxy. A color excess of E(b-y) = 0.057 mag (E(B-V) = 0.077 mag) is obtained for a distance modulus m-M = 10. A secondary result of this investigation is the discovery of six suspected variable stars, as well as ten observations of V Triangulum, a β Lyrae eclipsing variable.

Abstract:

Photometric (uvby β) observations ofthe prototype variable BL Her are described. The photometry indicates the variable is reddened. We have adopted E(b — y) = 0ṃ055. Intrinsic (b—y) and c₁ values are used to derive the mean temperature and surface gravity ‹T eff› = 6660 K, and ‹log g› = 2.46. The (m₁ =0.198 indicating the variable is very metal strong. We infer that [Fe/H] = + 0.20. An application of a modified Baade-Wesselink analysis to the photometric and radial-velocity data in the phase interval 0.45 ≤ φ ≤ 0.775, when most ofthe light variation can be attributed to a change in radius, yields (R) = 8.5 R⊙ and ‹Mv› = -0.5. The radius and surface gravity indicate that the mass is 𝕸 ≃ 0.75 𝕸⊙

Abstract: The authors report accidental errors and blanketing sensitivities for seven disk K giant temperature indices: Johnson J-K, Cousins R-I, Johnson R-I, Kron R-I, the Spinrad-Taylor T index. T1-T2, and V-K. The authors ultimately compare these indices to a blanketing-free color index, with the latter being derived from narrowband photometry, empirical blocking data, and a model-atmosphere backwarming correction. They also investigate the anomalous R band blanketing reported by Frogel, Whitford, and Rich for Baade's Window K giants.

Abstract: The authors present new data which will contribute to an analysis of the so-called super-metal-rich K giants. The results include DDO photometry and photomultiplier scanner data; some of the latter reflect blanketing and feature strengths, and the rest bear primarily on stellar temperatures. Some of the scanner data are transformed to the Cousins R-I system and are given with previously published measurements on this system.

Abstract:

Photometry (uvby β) of EH Lib has been secured and analyzed. A small correction is made to the period in order to better predict times of light maxima. A reddening value, E(b — y) = +0ṃ041, is derived from standard calibrations applied to the photometry. Intrinsic (b—y) and c₁ values are used to determine a mean effective temperature, ‹Teff› = 7840 K, and a mean surface gravity, ‹log g› = 4.08. The metal abundance, [Fe/H] = -0.015, is determined from δm₁ Using new and previously published spectroscopie data, a mean radius, ‹R› = 2.4 R⊙, is derived using a Wesselink method. The radius and effective temperature indicate a mean absolute bolometric magnitude, ‹Mbol› = + 1.5. Also a m

Abstract:

Over 700 observations of HD 200925 in the uvby and ß systems have been secured and analyzed. Our data show that this variable is multiperiodic. A reddening value, E(b-y) = 0ṃ029, has been derived from the observations. The reddening-corrected normals for y, (b-y), and c₁ yield a mean effective temperature, ‹Teff›=7020 K, a mean surface gravity, ‹log g›=3.44, and a mean bolometric magnitude, ‹Mbol› = 0ṃ8. We determine a preliminary mean radius, ‹R› = 4.1 R⊙. Our m₁ data show that the blanketing is high, but this index varies in an anomalous way which precludes a definitive determination of [Fe/H]. We consider two possible explanations for the behavior of the m₁ index. One is high microturbulance excited by the secondary pulsation mode, the other is the Am/Fm phenomenon. We find that the parameters from the Imbert (1980) radial velocity curve are essentially unchanged by our analysis. The Baade-Wesselink method fails for this star.