Photoelectric measurements of the λ4200 A CN band and the G band in G8-K5 spectra
Abstract
A description is given of a rapid method of using a spectrometer to give reproducible photoelectric measures of integrated intensities over significant features of stellar spectra, without the necessity for a sky of photometric quality. The accuracy achieved is I per cent. The A4200 A CN band has been measured in 712 late-type stars and the G band in 212 of these. Absolute magnitudes derived from CN intensities have mean errors of at least 1m .5. There is only a weak correlation of weak CN with high space velocity. "Weak-line" stars have no anomaly in their CN absorption; "strong-line" stars have slightly enhanced CN. For G to Ki stars the spectral type deduced from G band intensities has a mean deviation of 0 15 class from the MK type. There is a small absolute magnitude effect, the G band strengthening with intrinsic luminosity. High-velocity stars have completely normal G band intensities. "Weakline" stars show the G band very slightly stronger," strong-line" stars show it slightly weaker than the mean, but the individual scatter is fairly large and the difference between the two groups is scarcely significant statistically.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- 1960
- DOI:
- 10.1093/mnras/120.4.287
- Bibcode:
- 1960MNRAS.120..287G