8 papers · 1 filter
Bright OB stars in the Galaxy.II. Wind variability in O supergiants as traced by H-alpha
N. Markova, J. Puls, S. Scuderi +1
We investigate the line-profile variability (lpv) of H-alpha for a large sample of O-type supergiants. We used the Temporal Variance Spectrum (TVS) analysis, developed by Fullerton…
Pox 186: an ultracompact galaxy with dominant ionized gas emission
N. G. Guseva, P. Papaderos, Y. I. Izotov +2
We present a ground-based optical spectroscopic and HST U, V, I photometric study of the blue compact dwarf (BCD) galaxy Pox 186. It is found that the emission of the low-surface b…
Deep VLT spectroscopy of the blue compact dwarf galaxies Tol 1214-277 and Tol 65
Y. I. Izotov, P. Papaderos, N. G. Guseva +2
We present VLT spectroscopic observations with different spectral resolutions and different slit orientations of the two metal-deficient blue compact dwarf (BCD) galaxies Tol 1214-…
Time-resolved photometry and spectroscopy of the new deeply-eclipsing SW Sextantis star HS 0728+6738
P. Rodriguez-Gil, B. T. Gaensicke, H. Barwig +2
We present time-resolved optical spectroscopy and photometry, and far-ultraviolet spectroscopy of HS 0728+6738, a cataclysmic variable discovered in the Hamburg Quasar Survey. We s…
Simultaneous visible and infrared spectro-polarimetry of a solar internetwork region
J. Sanchez Almeida, I. Dominguez Cerdena, F. Kneer
We present the first simultaneous infrared (IR) and visible spectro-polarimetric observations of a solar internetwork region. The Fe I lines at 6301.6 A, 6302.5 A, 15648 A, and 156…
The N/O abundance ratio in the lowest-metallicity blue compact dwarf galaxies
Y. Izotov, F. Chaffee, C. Foltz +6
The results of the N/O abundance determination in a sample of low-metallicity blue compact dwarf (BCD) galaxies based on new spectroscopic observations with large telescopes (Keck,…