Browsing by Author "Vogt, Nikolaus"
Now showing 1 - 10 of 10
Results Per Page
Sort Options
- ItemA Novel Growth Mode of Alkane Films on a Sio2 Surface(2003) Mo, H.; Vogt, Nikolaus
- ItemA Search for Rapid Photometric Variations in Southern Be and Bn Stars(1991) Barrera S., Luis.; Vogt, Nikolaus
- ItemAn astrometric catalogue of southern and equatorial dwarf novae(1992) Vogt, Nikolaus
- ItemAtomic Force Microscopy Measurements of Topography and Friction on Dotriacontane Films Adsorbed on a Sio2 Surface(2005) Trogisch, S.; Vogt, Nikolaus
- ItemCorrelation and variability of the HeI 4471 and MgII 4481 absorption lines in Be stars: A possible diagnostic tool for nonradial pulsations(1990) Vogt, Nikolaus; Barrera, Luis H.; Navarro, MarioIn a total of 181 photographic spectrograms, obtained at the Manuel Foster Observatory of the Catholic University in Santiago (Chile), the equivalent widths of the absorption lines HeI 4471 and MgII 4481 have been determined for 10 selected southern Be stars and 4 normal B-type stars. The mean equivalent widths of each star are compared to published mean values from largers samples of B stars. On the average, Be stars coincide with normal B-type stars in their equivalent width. However, a striking difference between rapidly and slowly rotating stars in their line ratios (HeI/MgII) was found, which is probably an artifact due to a systematic misclassification of spectral types of rapidly rotating B stars (v sini>200 km s?1). Six of the ten Be stars show evidence for variability in HeI and/or MgII with time-scales shorter than a few days and amplitudes up to a factor 2 in equivalent width. Line variability occurs in the entire range of projected rotation velocity (70 km s?1
- ItemEvidence for Hibernation From a Statistical Analysis of Nova Eruption Amplitudes(1990) Vogt, Nikolaus
- ItemNanoscale observation of delayering in alkane films(2007) Bai, M.; Vogt, Nikolaus
- ItemThe Photometric Period of the Recurrent Nova T Pyxidis(1992) Vogt, Nikolaus
- ItemThe photometric variations of the Ap star HD34631(1991) Vogt, Nikolaus
- ItemV/R Variations in H B Emision Profiles of Be Stars(1991) Vogt, Nikolaus