18 citations · 36 across the 4 of their papers we have counts for
3 papers · 1 filter
Variability in Proto-Planetary Nebulae: VII. Light Curve Studies of Five Medium-bright, Oxygen-rich or Mixed-chemistry Post-AGB/Post-RGB Objects
Bruce J. Hrivnak, Gary Henson, Todd C. Hillwig +3
We have monitored over a ten-year interval the light variations of five evolved stars with very large mid-infrared excesses. All five objects appear to have oxygen-rich or mixed ox…
Carbon and Oxygen Isotopic Ratios. II. Semiregular Variable M Giants
Thomas Lebzelter, Kenneth H. Hinkle, Oscar Straniero +3
Carbon and oxygen isotopic ratios are reported for a sample of 51 SRb- and Lb-type variable asymptotic giant branch stars. Vibration-rotation first- and second-overtone CO lines in…
Variability in Proto-Planetary Nebulae: IV. Light Curve Analyses of Four Oxygen-Rich, F Spectral-Type Objects
Bruce J. Hrivnak, Wenxian Lu, Kristie A. Nault
We present new light curves covering 14 to 19 years of observations of four bright proto-planetary nebulae (PPNs), all O-rich and of F spectral type. They each display cyclical lig…