Zobrazeno 1 - 10
of 208
pro vyhledávání: '"Oswalt T"'
Autor:
Otani, Tomomi, von Hippel, Ted, Buzasi, Derek, Oswalt, T. D., Stone-Martinez, Alexander, Majewski, Patrice
Accurate stellar ages are essential for our understanding of the star formation history of the Milky Way, Galactic chemical evolution, and to constrain exoplanet formation models. Gyrochronology, a relationship between stellar rotation and age, appea
Externí odkaz:
http://arxiv.org/abs/2105.07266
Autor:
Mackebrandt, F., Schuh, S., Silvotti, R., Kim, S. -L., Kilkenny, D., Green, E. M., Lutz, R., Nagel, T., Provencal, J. L., Otani, T., Oswalt, T. D., Benatti, S., Lanteri, L., Bonanno, A., Frasca, A., Janulis, R., Paparó, M., Molnár, L., Claudi, R., Østensen, R. H.
Publikováno v:
A&A 638, A108 (2020)
We aim to investigate variations in the arrival time of coherent stellar pulsations due to the light-travel time effect to test for the presence of sub-stellar companions. Those companions are the key to one possible formation scenario of apparently
Externí odkaz:
http://arxiv.org/abs/2004.04764
Autor:
Henze, M., Darnley, M. J., Williams, S. C., Kato, M., Hachisu, I., Anupama, G. C., Arai, A., Boyd, D., Burke, D., Chinetti, K., Ciardullo, R., Cook, L. M., Cook, M. J., Erdman, P., Gao, X., Harris, B., Hartmann, D. H., Hornoch, K., Horst, J. Chuck, Hounsell, R., Husar, D., Itagaki, K., Kabashima, F., Kafka, S., Kaur, A., Kiyota, S., Kojiguchi, N., Kucakova, H., Kuramoto, K., Maehara, H., Mantero, A., Masci, F. J., Matsumoto, K., Naito, H., Ness, J. -U., Nishiyama, K., Oksanen, A., Osborne, J. P., Page, K. L., Paunzen, E., Pavana, M., Pickard, R., Prieto-Arranz, J., Rodriguez-Gil, P., Sala, G., Sano, Y., Shafter, A. W., Sugiura, Y., Tan, H., Tordai, T., Vratil, J., Wagner, R. M., Watanabe, F., Williams, B. F., Bode, M. F., Bruno, A., Buchheim, B., Crawford, T., Goff, B., Hernanz, M., Igarashi, A. S., Jose, J., Motta, M., O'Brien, T. J., Oswalt, T., Poyner, G., Ribeiro, V. A. R. M., Sabo, R., Shara, M. M., Shears, J., Starkey, D., Starrfield, S., Woodward, C. E.
Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and a high accretion rate, which is the most pr
Externí odkaz:
http://arxiv.org/abs/1803.00181
Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario. EC~20117-4014 (=V4640~Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion (O'Donoghue et al.
Externí odkaz:
http://arxiv.org/abs/1708.06029
We present the fractional distribution of spectroscopic subtypes, range and distribution of surface temperatures, and kinematical properties of the white dwarfs within 25pc of the sun. There is no convincing evidence of halo white dwarfs in the total
Externí odkaz:
http://arxiv.org/abs/1401.4989
Approximately 70 percent of the nearby white dwarfs appear to be single stars, with the remainder being members of binary or multiple star systems. The most numerous and most easily identifiable systems are those in which the main sequence companion
Externí odkaz:
http://arxiv.org/abs/1307.8047
We present a spectroscopically identified catalogue of 72 DA white dwarfs from the LAMOST pilot survey. 35 are found to be new identifications after cross-correlation with the Eisenstein et al. and Villanova catalogues. The effective temperature and
Externí odkaz:
http://arxiv.org/abs/1304.3551
We present chromospheric activity index $S\rm_{HK}$ measurements for over 13,000 F, G and K disk stars with high signal-to-noise ratio ($>$ 60) spectra in the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) spectroscopic sample. A parameter $\de
Externí odkaz:
http://arxiv.org/abs/1304.3537
The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations
Externí odkaz:
http://arxiv.org/abs/1201.3822
We present the chromospheric activity (CA) levels, metallicities and full space motions for 41 F, G, K and M dwarf stars in 36 wide binary systems. Thirty-one of the binaries, contain a white dwarf component. In such binaries the total age can be est
Externí odkaz:
http://arxiv.org/abs/1101.3257