Zobrazeno 1 - 10
of 54
pro vyhledávání: '"Woolf, Vincent M"'
Autor:
Woolf, Vincent M., Wallerstein, George
We report iron and titanium abundance measurements from high resolution spectra in a volume-limited sample of 106 M0 and M0.5 dwarf stars. The sample includes stars north of the celestial equator and closer than 29 parsecs. The results imply that the
Externí odkaz:
http://arxiv.org/abs/2003.11447
Autor:
Hema, B. P., Pandey, Gajendra, Kamath, Devika, Rao, N. Kameswara, Lambert, David, Woolf, Vincent M.
Abundance analyses of the two newly discovered R Coronae Borealis (RCB) stars ASAS-RCB-8 and ASAS-RCB-10 were conducted using high-resolution optical spectra and model atmospheres. Their chemical compositions place the pair among the majority class o
Externí odkaz:
http://arxiv.org/abs/1707.01268
High-resolution optical spectra of the R Coronae Borealis (RCB) star V532 Oph at light maximum are discussed. The absolute visual magnitude M_V of the star is found to be -4.9 \pm 0.5. The elemental abundances suggest the star belongs to the majority
Externí odkaz:
http://arxiv.org/abs/1407.3696
Autor:
Rao, N. Kameswara, Lambert, David L., Garcia-Hernandez, D. A., Jeffery, C. Simon, Woolf, Vincent M., McArthur, Barbara
The remarkable hot R Coronae Borealis star DY Cen is revealed to be the first and only binary system to be found among the R Coronae Borealis (RCB) stars and their likely relatives, including the Extreme Helium stars and the hydrogen-deficient carbon
Externí odkaz:
http://arxiv.org/abs/1210.4199
Autor:
Woolf, Vincent M., West, Andrew A.
We present evidence that there is an M dwarf problem similar to the previously identified G dwarf and K dwarf problems: the number of low-metallicity M dwarfs is not sufficient to match simple closed-box models of local Galactic chemical evolution. W
Externí odkaz:
http://arxiv.org/abs/1202.3078
Autor:
Woolf, Vincent M, Wallerstein, George
Publikováno v:
Publ.Astron.Soc.Pac.118:218-226,2006
We report progress in the calibration of a method to determine cool dwarf star metallicities using molecular band strength indices. The molecular band index to metallicity relation can be calibrated using chemical abundances calculated from atomic li
Externí odkaz:
http://arxiv.org/abs/astro-ph/0510148
Autor:
Woolf, Vincent M., Wallerstein, George
Publikováno v:
Mon.Not.Roy.Astron.Soc. 356 (2005) 963-968
We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda / Delta l
Externí odkaz:
http://arxiv.org/abs/astro-ph/0410452
Autor:
Woolf, Vincent M., Jeffery, C. Simon
Publikováno v:
Astron.Astrophys. 395 (2002) 535-540
We report the analysis of optical spectra of the extreme helium star LSS 3184 (BX Cir) to determine its effective temperature and gravity throughout its pulsation cycle. The spectra were also used to measure its chemical abundances. We report rest gr
Externí odkaz:
http://arxiv.org/abs/astro-ph/0208269
Publikováno v:
Mon.Not.Roy.Astron.Soc. 329 (2002) 497
We present an analysis of high-speed spectroscopy of the pulsating subdwarf B star PG 1605+072. Periodic radial motions are detected at frequencies similar to those reported for photometric variations in the star, with amplitudes of up to 6 km/s. Dif
Externí odkaz:
http://arxiv.org/abs/astro-ph/0111225
Autor:
Rao, N. Kameswara, Lambert, David L., Adams, Mark T., Doss, David R., Gonzalez, Guillermo, Hatzes, Artie P., James, C. Renee, Johns-Krull, C. M., Luck, R. Earle, Pandey, Gajendra, Reinsch, Klaus, Tomkin, Jocelyn, Woolf, Vincent M.
A set of high-resolution optical spectra of RCrB acquired before, during, and after its 1995-1996 decline is discussed. All of the components reported from earlier declines are seen. This novel dataset provides new information on these components inc
Externí odkaz:
http://arxiv.org/abs/astro-ph/9907099