scholarly journals Spectroscopic Determination of Atmospheric Parameters of Solar-Type Stars: Description of the Method and Application to the Sun

2002 ◽  
Vol 54 (3) ◽  
pp. 451-462 ◽  
Author(s):  
Yoichi Takeda ◽  
Michiko Ohkubo ◽  
Kozo Sadakane
Keyword(s):  
Spectroscopic Determination ◽  
The Sun ◽  
Atmospheric Parameters ◽  
Solar Type

scholarly journals Detailed Analyses of Four Solar Analogs Analysed On High S/N CFH and ESO Spectra

1988 ◽  
Vol 132 ◽  
pp. 429-432
Author(s):  
C. Bentolila ◽  
G. Cayrel de Strobel
Keyword(s):  
High Resolution ◽  
Effective Temperature ◽  
The Sun ◽  
Atmospheric Parameters ◽  
Iron Abundance ◽  
Solar Type ◽  
Solar Analogs

Four solar type G stars claimed to be photometrically very similar to the Sun have been analyzed in detail on high resolution, high S/N spectra. Their atmospheric parameters : effective temperature, spectroscopic gravity, microturbulence and iron abundance, [Fe/H], have been determined.

scholarly journals Lithium Abundances in Solar-Type Stars

2000 ◽  
Vol 198 ◽  
pp. 495-497 ◽  
Author(s):  
L. da Silva ◽  
G. F. Porto de Mello
Keyword(s):  
Angular Momentum ◽  
Momentum Distribution ◽  
The Sun ◽  
Atmospheric Parameters ◽  
Solar Type ◽  
Subgiant Stars ◽  
High Degree ◽  
Li Content

We report Li abundances from the λ6707 line for 19 nearby dwarf and subgiant solar-type stars. The unevolved stars in this sample present high (> 2.00) Li abundances. We found a few cases of subgiant stars which present high Li content. The Sun seems to be part of a population of nearly unevolved stars which have depleted their Li to a high degree: all other metal-normal, near ZAMS stars in our sample show higher than solar Li content. There seems to be no correlation of the degree of Li depletion with mass, atmospheric parameters or state of evolution: as an example we found a star (HR1532) almost identical to the Sun in its state of evolution and atmospheric parameters, but with over ten times the solar Li abundance. We propose that different histories of angular momentum distribution at star birth, and/or post-birth angular momentum evolution, may account for these differences.

scholarly journals Distribution of refractory and volatile elements in CoRoT planet host stars

2009 ◽  
Vol 5 (S265) ◽  
pp. 424-425
Author(s):  
C. Chavero ◽  
R. de la Reza ◽  
R. C. Domingos ◽  
N. A. Drake ◽  
C. B. Pereira ◽  
...  
Keyword(s):  
Internal Migration ◽  
Spectroscopic Determination ◽  
Atmospheric Parameters ◽  
Chemical Abundances ◽  
Volatile Elements ◽  
Preliminary Results ◽  
Transiting Planets ◽  
Host Stars ◽  
Flat Distribution

AbstractWe report on preliminary results of spectroscopic determination of the atmospheric parameters and chemical abundances of the parent stars of the recently discovered transiting planets CoRoT-2b and CoRoT-4b. We found a flat distribution of the relative abundances as a function of their condensation temperatures. Also, we introduce a new methodology to investigate a relation between the abundances of these stars and the internal migration of their planets.

scholarly journals On the Spectroscopic Determination of Atmospheric Parameters and O/Fe Abundances of RR Lyrae Stars

2006 ◽  
Vol 58 (2) ◽  
pp. 389-406 ◽  
Author(s):  
Yoichi Takeda ◽  
Satoshi Honda ◽  
Wako Aoki ◽  
Masahide Takada-Hidai ◽  
Gang Zhao ◽  
...  
Keyword(s):  
Spectroscopic Determination ◽  
Atmospheric Parameters ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Lyrae Stars

scholarly journals {High dispersion spectroscopy of solar-type superflare stars with Subaru/HDS

2015 ◽  
Vol 11 (S320) ◽  
pp. 138-143
Author(s):  
Yuta Notsu ◽  
Satoshi Honda ◽  
Hiroyuki Maehara ◽  
Shota Notsu ◽  
Takuya Shibayama ◽  
...  
Keyword(s):  
Binary System ◽  
Large Amplitude ◽  
Rotational Velocity ◽  
Brightness Variation ◽  
High Dispersion ◽  
The Sun ◽  
Atmospheric Parameters ◽  
Spectroscopic Observations ◽  
Solar Type

AbstractWe carried out spectroscopic observations with Subaru/HDS of 50 solar-type superflare stars found from Kepler data. More than half (34 stars) of the target stars show no evidence of the binary system, and we confirmed atmospheric parameters of these stars are roughly in the range of solar-type stars.We then conducted the detailed analyses for these 34 stars. First, the value of the “v sin i” (projected rotational velocity) measured from spectroscopic results is consistent with the rotational velocity estimated from the brightness variation. Second, there is a correlation between the amplitude of the brightness variation and the intensity of Ca II IR triplet line. All the targets expected to have large starspots because of their large amplitude of the brightness variation show high chromospheric activities compared with the Sun. These results support that the brightness variation of superflare stars is explained by the rotation of a star with large starspots.

scholarly journals Spectroscopic Determination of Stellar Atmospheric Parameters: Application to Mid-F through Early-K Dwarfs and Subgiants

2002 ◽  
Vol 54 (6) ◽  
pp. 1041-1056 ◽  
Author(s):  
Yoichi Takeda ◽  
Bun’ei Sato ◽  
Eiji Kambe ◽  
Kozo Sadakane ◽  
Michiko Ohkubo
Keyword(s):  
Spectroscopic Determination ◽  
Atmospheric Parameters

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

A Search for Dyson Spheres around Late-Type Stars in the Solar Neighborhood II

1997 ◽  
Vol 161 ◽  
pp. 707-709 ◽  
Author(s):  
Jun Jugaku ◽  
Shiro Nishimura
Keyword(s):  
Solar Neighborhood ◽  
The Sun ◽  
Late Type ◽  
Solar Type

AbstractWe continued our search for partial (incomplete) Dyson spheres associated with 50 solar-type stars (spectral classes F, G, and K) within 25 pc of the Sun. No candidate objects were found.

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