Zobrazeno 1 - 10
of 199
pro vyhledávání: '"Reiff E"'
Autor:
Provencal, J. L., Montgomery, M. H., Kanaan, A., Shipman, H. L., Childers, D., Baran, A., Kepler, S. O., Reed, M., Zhou, A., Eggen, J., Watson, T. K., Winget, D. E., Thompson, S. E., Riaz, B., Nitta, A., Kleinman, S. J., Crowe, R., Slivkoff, J., Sherard, P., Purves, N., Binder, P., Knight, R., Kim, S. -L., Chen, Wen-Ping, Yang, M., Lin, H. C., Lin, C. C., Chen, C. W., Jiang, X. J., Sergeev, A. V., Mkrtichian, D., Janiashvili, E., Andreev, M., Janulis, R., Siwak, M., Zola, S., Koziel, D., Stachowski, G., Paparo, M., Bognar, Zs., Handler, G., Lorenz, D., Steininger, B., Beck, P., Nagel, T., Kusterer, D., Hoffman, A., Reiff, E., Kowalski, R., Vauclair, G., Charpinet, S., Chevreton, M., Solheim, J. E., Pakstiene, E., Fraga, L., Dalessio, J.
Publikováno v:
Astrophys.J.693:564-585,2009
We report on the analysis of 436.1 hrs of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transfor
Externí odkaz:
http://arxiv.org/abs/0811.0768
Previous studies aiming at the iron-abundance determination in three PG 1159 stars (K 1-16, PG 1159-035, NGC 7094) and a [WC]-PG 1159 transition star (Abell 78) have revealed that no object shows any iron line in the UV spectrum. The stars are iron-d
Externí odkaz:
http://arxiv.org/abs/0804.2372
Spectral analyses of H-deficient post-AGB stars have shown that a small group of four extremely hot objects exists which have almost pure He absorption-line spectra in the optical. These are classified as O(He) stars. For their evolution there are tw
Externí odkaz:
http://arxiv.org/abs/0804.2366
A possible origin of the iron-deficiency in PG1159 stars could be neutron captures on Fe nuclei. A nickel overabundance would corroborate this idea. Consequently we are looking for nickel lines in PG1159 stars. Prime targets are relatively cool objec
Externí odkaz:
http://arxiv.org/abs/0803.0066
Autor:
Schuh, S., Traulsen, I., Nagel, T., Reiff, E., Homeier, D., Schwager, H., Kusterer, D. -J., Lutz, R., Schreiber, M. R.
Methods to measure masses of PG1159 stars in order to test evolutionary scenarios are currently based on spectroscopic masses or asteroseismological mass determinations. One recently discovered PG1159 star in a close binary system may finally allow t
Externí odkaz:
http://arxiv.org/abs/0712.0739
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usually-hidden intershell region. T
Externí odkaz:
http://arxiv.org/abs/0710.4506
PG1159-035 is the prototype of the PG1159 spectral class which consists of extremely hot hydrogen-deficient (pre-) white dwarfs. It is also the prototype of the GW Vir variables, which are non-radial g-mode pulsators. The study of PG1159 stars reveal
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610592
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usually-hidden intershell region. T
Externí odkaz:
http://arxiv.org/abs/astro-ph/0603225
Publikováno v:
ASP Conf.Ser. 349 (2006) 323
GW Vir variables are the pulsating members in the spectroscopic class of PG 1159 stars. In order to understand the characteristic differences between pulsating and non-pulsating PG 1159 stars, we analyse FUSE spectra of eleven objects, of which six a
Externí odkaz:
http://arxiv.org/abs/astro-ph/0601566
Autor:
Werner, K., Hoffmann, A. I. D., Jahn, D., Rauch, T., Reiff, E., Traulsen, I., Kruk, J. W., Dreizler, S.
Publikováno v:
AIP Conf.Proc.804:129-132,2006
We present new results from our spectral analyses of very hot central stars achieved since the last IAU Symposium on planetary nebulae held in Canberra 2001. The analyses are mainly based on UV and far-UV spectroscopy performed with the Hubble Space
Externí odkaz:
http://arxiv.org/abs/astro-ph/0508108