Zobrazeno 1 - 10
of 114
pro vyhledávání: '"Bohlender, David A."'
Autor:
Hrivnak, Bruce J., Van de Steene, Griet, Van Winckel, Hans, Sperauskas, Julius, Bohlender, David, Lu, Wenxian
Publikováno v:
Astrophysical Journal 846, 96 - 2017 September 10
We present the results of an expanded, long-term radial velocity search (25 yrs) for evidence of binarity in a sample of seven bright proto-planetary nebulae (PPNe). The goal is to investigate the widely-held view that the bipolar or point-symmetric
Externí odkaz:
http://arxiv.org/abs/1708.03614
Autor:
Sikora, James, Wade, Gregg, Bohlender, David, Shultz, Matt, Adelman, Saul, Alecian, Evelyne, Hanes, David, Monin, Dmitry, Neiner, Coralie, MiMeS, the, Collaborations, BinaMIcS
We present our analysis of HD~35502 based on high- and medium-resolution spectropolarimetric observations. Our results indicate that the magnetic B5IVsnp star is the primary component of a spectroscopic triple system and that it has an effective temp
Externí odkaz:
http://arxiv.org/abs/1605.01353
Based on gas-phase laboratory spectra at 6 K, Campbell et al. (2015) confirmed that the diffuse interstellar bands (DIBs) at 9632.7 and 9577.5A are due to absorption by the fullerene ion C60+. They also reported the detection of two other, weaker ban
Externí odkaz:
http://arxiv.org/abs/1509.06818
Autor:
Sikora, James, Wade, Gregg, Bohlender, David, Neiner, Coralie, Oksala, Mary, Shultz, Matt, Cohen, David, ud-Doula, Asif, Grunhut, Jason, Monin, Dmitry, Owocki, Stan, Petit, Véronique, Rivinius, Thomas, Townsend, Richard
In this paper we report 23 magnetic field measurements of the B3IV star HD 23478: 12 obtained from high resolution Stokes $V$ spectra using the ESPaDOnS (CFHT) and Narval (TBL) spectropolarimeters, and 11 from medium resolution Stokes $V$ spectra obt
Externí odkaz:
http://arxiv.org/abs/1505.02427
Autor:
Hrivnak, Bruce J., Lu, Wenxian, Sperauskas, Julius, Van Winckel, Hans, Bohlender, David, Zacs, Laimons
Publikováno v:
Astrophysical Journal 2013, 766, 116; Erratum 2013, 777, 80
We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, to
Externí odkaz:
http://arxiv.org/abs/1310.8558
Autor:
Monin, Dmitry, Bohlender, David
The fast-switching DAO spectropolarimeter mounted on the 1.8-m Plaskett telescope started operation in 2007. Almost 14,000 medium-resolution (R=15,000) polarimetric spectra of 65 O - F type stars have been obtained since then in the course of three o
Externí odkaz:
http://arxiv.org/abs/1110.1415
Autor:
Bohlender, David A., Monin, Dmitry
We report the detection of a strong, reversing magnetic field and variable H-alpha emission in the bright helium-weak star HD 176582 (HR 7185). Spectrum, magnetic and photometric variability of the star are all consistent with a precisely determined
Externí odkaz:
http://arxiv.org/abs/1103.1685
Autor:
Hrivnak, Bruce J., Lu, Wenxian, Wefel, Katrina Loewe, Bohlender, David, Morris, S. C., Woodsworth, Andrew W., Scarfe, C. D.
The shaping of the nebula is currently one of the outstanding unsolved problems in planetary nebula (PN) research. Several mechanisms have been proposed, most of which require a binary companion. However, direct evidence for a binary companion is lac
Externí odkaz:
http://arxiv.org/abs/1012.5658
The helium-peculiar star a Cen exhibits line profile variations of elements such as iron, nitrogen and oxygen in addition to its well-known extreme helium variability. New high S/N, high-resolution spectra are used to perform a quantitative measureme
Externí odkaz:
http://arxiv.org/abs/1007.0977
Autor:
Hrivnak, Bruce J., Van Winckel, Hans, Reyniers, Maarten, Bohlender, David, Waelkens, Christoffel, Lu, Wenxian
The metal-poor post-AGB star HD 46703 is shown to be a single-line spectroscopic binary with a period of 600 days, a high velocity of -94 km/s, and an orbital eccentricity of 0.3. Light curve studies show that it also pulsates with a period of 29 day
Externí odkaz:
http://arxiv.org/abs/0807.3752