scholarly journals Ultraviolet and optical spectroscopy of AGB stars showing UV excess

2018 ◽  
Vol 482 (4) ◽  
pp. 4697-4712 ◽  
Author(s):  
Roberto Ortiz ◽  
Martín A Guerrero ◽  
Roberto D D Costa
Keyword(s):  
Optical Spectroscopy ◽  
Agb Stars ◽  
Uv Excess

The Atmospheres of AGB Stars: Opacities, Radiative Transfer and Models

2008 ◽  
Vol 28 ◽  
pp. 67-74 ◽  
Author(s):  
B. Aringer ◽  
W. Nowotny ◽  
S. Höfner
Keyword(s):  
Radiative Transfer ◽  
Agb Stars

Using optical spectroscopy for the study of paper degradation

2006 ◽  
Vol 49 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Mauro Missori ◽  
Marcofabio Righini
Keyword(s):  
Optical Spectroscopy ◽  
Paper Degradation

Properties of Ultraviolet Exposed Camptothecin Studied by Using Optical Spectroscopy Methods

2016 ◽  
Vol 19 (4) ◽  
pp. 319-324 ◽  
Author(s):  
Blanka Ziomkowska ◽  
Tomasz Wybranowski ◽  
Michal Cyrankiewicz ◽  
Stefan Kruszewski
Keyword(s):  
Optical Spectroscopy

scholarly journals Gaia DR2 data and the evolutionary status of eight high-velocity hot post-AGB candidates

2020 ◽  
Vol 72 (6) ◽  
Author(s):  
Mudumba Parthasarathy ◽  
Tadafumi Matsuno ◽  
Wako Aoki
Keyword(s):  
Effective Temperature ◽  
High Velocity ◽  
Circumstellar Dust ◽  
Evolutionary Status ◽  
Agb Stars ◽  
Horizontal Branch ◽  
Dust Shells ◽  
The Past ◽  
Gaia Dr2 ◽  
Branch Star

Abstract From Gaia DR2 data of eight high-velocity hot post-AGB candidates, LS 3593, LSE 148, LS 5107, HD 172324, HD 214539, LS IV −12 111, LS III +52 24, and LS 3099, we found that six of them have accurate parallaxes which made it possible to derive their distances, absolute visual magnitudes (MV) and luminosity (log L/L⊙). All the stars except LS 5107 have an accurate effective temperature (Teff) in the literature. Some of these stars are metal poor, and some of them do not have circumstellar dust shells. In the past, the distances of some stars were estimated to be 6 kpc, which we find to be incorrect. The accurate Gaia DR2 parallaxes show that they are relatively nearby, post-AGB stars. When compared with post-AGB evolutionary tracks we find their initial masses to be in the range 1 M⊙ to 2 M⊙. We find the luminosity of LSE 148 to be significantly lower than that of post-AGB stars, suggesting that this is a post-horizontal-branch star or post-early-AGB star. LS 3593 and LS 5107 are new high-velocity hot post-AGB stars from Gaia DR2.

Intraspecific differentiation of sandflies specimens by optical spectroscopy and multivariate analysis

2021 ◽  
Author(s):  
Aline E. Casaril ◽  
Carlos G. Santos ◽  
Bruno S. Marangoni ◽  
Sandro M. Lima ◽  
Luis H.C. Andrade ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Optical Spectroscopy ◽  
Intraspecific Differentiation

Growth of pentacene on α−Al2O3 (0001) studied by in situ optical spectroscopy

2017 ◽  
Vol 1 (4) ◽  
Author(s):  
Lei Zhang ◽  
X. Fu ◽  
M. Hohage ◽  
P. Zeppenfeld ◽  
L. D. Sun
Keyword(s):  
Optical Spectroscopy ◽  
Α Al2o3

scholarly journals Discovery of Infrared Stars in Globular Clusters in the Magellanic Clouds and Their Light Variations

1998 ◽  
Vol 11 (1) ◽  
pp. 395-395
Author(s):  
S. Nishida ◽  
T. Tanabé ◽  
S. Matsumoto ◽  
T. Onaka ◽  
Y. Nakada ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Main Sequence ◽  
Near Infrared ◽  
Magellanic Clouds ◽  
Infrared Light ◽  
Agb Stars ◽  
Dust Shells ◽  
Infrared Stars ◽  
Infrared Survey

A systematic near-infrared survey was made for globular clusters in the Magellanic Clouds. Two infrared stars were discovered in NGC419 (SMC) and NGC1783 (LMC). NGC419 and NGC1783 are well-studied rich globular clusters whose turn-off masses and ages are estimated MTO ~ 2.0 Mʘ and т ~1.2 Gyr for NGC419, and MT0 ~ 2.0 Mʘ and т ʘ 0.9 Gyr for NGC1783, respectively. The periods of the infrared light variations were determined to be 540 dfor NGC419IR1 and to be 480 d for NGC1783IR1, respectively. Comparison of the measurements with the period—if magnitude relation for carbon Miras in the LMC by Groenewegen and Whitelock(1996) revealed that the Kmagnitudes of the infrared stars were fainter by about 0.3 — 0.8 magnitude than those predicted by the P — K relation. This deviation can be explained if the infrared stars are surrounded by thick dust shells and are obscured even in the K band. The positions of NGC419IR1and NGC1783IR1 on the P — K diagram suggest that AGB stars with the main sequence masses of about 2 Mʘ start their heavy mass-loss when P ʘ 500 d.

Accurate determination of the onset wavelength (λonset) in optical spectroscopy

2021 ◽  
Vol 265 ◽  
pp. 107544
Author(s):  
Austin M. Wallace ◽  
Christine Curiac ◽  
Jared H. Delcamp ◽  
Ryan C. Fortenberry
Keyword(s):  
Optical Spectroscopy ◽  
Accurate Determination
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