Statistical properties of a sample of periodically variable B-type supergiants ⋆
... since they are (by definition) free from saturation effects and least affected by collisional broadening. We have the following lines at our disposal: either Si II 4128-4130 or Si III 45524567-4574 (depending on spectral type), Mg II 4481 (in the same spectral order as He I 4471) and, for slow rotat ...
... since they are (by definition) free from saturation effects and least affected by collisional broadening. We have the following lines at our disposal: either Si II 4128-4130 or Si III 45524567-4574 (depending on spectral type), Mg II 4481 (in the same spectral order as He I 4471) and, for slow rotat ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
... velocity of Sextans A (Huchtmeier & Richter 1986). The average FWHM of the emission is 47 km/s corresponding to a (1σ) velocity dispersion of 20 km/s. This is in excellent agreement with a thermal velocity (22 km/s) of a warm interstellar medium if a temperature of 10 000 K is assumed. In the sky-su ...
... velocity of Sextans A (Huchtmeier & Richter 1986). The average FWHM of the emission is 47 km/s corresponding to a (1σ) velocity dispersion of 20 km/s. This is in excellent agreement with a thermal velocity (22 km/s) of a warm interstellar medium if a temperature of 10 000 K is assumed. In the sky-su ...
Hot Horizontal Branch Stars in the Galactic Bulge. I
... These are mostly cool or warm BHB’s (Moehler, Sweigart, & Catelan 1999), with few if any of the hottest, faintest types, the subdwarf sdB stars and their relatively rare successors the sdO stars. Surprisingly, significant numbers of sdB/O’s are found in metal-rich populations in the Milky Way; even ...
... These are mostly cool or warm BHB’s (Moehler, Sweigart, & Catelan 1999), with few if any of the hottest, faintest types, the subdwarf sdB stars and their relatively rare successors the sdO stars. Surprisingly, significant numbers of sdB/O’s are found in metal-rich populations in the Milky Way; even ...
Hot subdwarf stars-galactic orbits and distribution perpendicular to
... Hot subdwarfs are blue, horizontal-branch like stars, representing the late stages of evolution of stars having started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatu ...
... Hot subdwarfs are blue, horizontal-branch like stars, representing the late stages of evolution of stars having started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatu ...
MPhil Thesis - Final - Suzanne Knight
... much more problematic. Due to their close proximity as well as their smaller size and dimness compared to the brighter parent stars, these planets are often lost in the star’s glare and are difficult to resolve. There have been attempts during the past decade to directly observe likely candidates. F ...
... much more problematic. Due to their close proximity as well as their smaller size and dimness compared to the brighter parent stars, these planets are often lost in the star’s glare and are difficult to resolve. There have been attempts during the past decade to directly observe likely candidates. F ...
Chemical analysis of 24 dusty (pre-) main
... O and S have approximately solar photospheric abundances, while several metals are depleted. Venn & Lambert (1990) pointed out that the λ Boo abundance pattern is comparable to the composition of the gas component of the interstellar medium (e.g. Heiter 2002): the depleted elements (Mg, Ca, Ti, Fe a ...
... O and S have approximately solar photospheric abundances, while several metals are depleted. Venn & Lambert (1990) pointed out that the λ Boo abundance pattern is comparable to the composition of the gas component of the interstellar medium (e.g. Heiter 2002): the depleted elements (Mg, Ca, Ti, Fe a ...
Do We Know of Any Maunder Minimum Stars?
... (Perryman et al. 1997; Perryman & ESA 1997). To increase the confidence in the results here, only those WMBV stars with more than two Keck observations are used in this work. The bulk of the ∼ 1000 stars in WMBV are currently being monitored for radial velocity variations and are typically bright, w ...
... (Perryman et al. 1997; Perryman & ESA 1997). To increase the confidence in the results here, only those WMBV stars with more than two Keck observations are used in this work. The bulk of the ∼ 1000 stars in WMBV are currently being monitored for radial velocity variations and are typically bright, w ...
Stellar evolution - Statistical Physics Group
... compared with the H R diagrams of star clusters and it was found that some of the qualitative features of these diagrams could readily be explained. I n particular, the idea that an individual cluster diagram contained stars of the same age and chemical composition but different mass, while the diff ...
... compared with the H R diagrams of star clusters and it was found that some of the qualitative features of these diagrams could readily be explained. I n particular, the idea that an individual cluster diagram contained stars of the same age and chemical composition but different mass, while the diff ...
preprint, pdf version - LESIA
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
Pulsed Accretion in the Young Binary &
... these have been identified as possible sites for the study of early stellar evolution and planetary formation. Stellar formation starts when a gravitational collapse is triggered in dense regions of slowly rotating gaseous clouds. As the gravitational force depends on the inverse-square of the dista ...
... these have been identified as possible sites for the study of early stellar evolution and planetary formation. Stellar formation starts when a gravitational collapse is triggered in dense regions of slowly rotating gaseous clouds. As the gravitational force depends on the inverse-square of the dista ...
Astronomy 250 - University of Victoria
... need only measure the displacement ∆λ of a spectral line from its expected wavelength λ, provided the latter is known. The radial velocity, vr , is then given by ...
... need only measure the displacement ∆λ of a spectral line from its expected wavelength λ, provided the latter is known. The radial velocity, vr , is then given by ...
“XRbinary”: A Program to Calculate the Orbital Light Curves of X
... For the most accurate calculations, equation 41 needs a large grid of specific intensities as a function of Tef f , log g, µ, and λ. The calculations can be simplified by assuming that the angular dependence can be separated into a limb-darkening function, and that the limbdarkening coefficients are ...
... For the most accurate calculations, equation 41 needs a large grid of specific intensities as a function of Tef f , log g, µ, and λ. The calculations can be simplified by assuming that the angular dependence can be separated into a limb-darkening function, and that the limbdarkening coefficients are ...
Stars & Galaxies - newmanlib.ibri.org
... • 'Galaxies' are what we call the huge star clusters that inhabit our universe. • These clusters range in size from ten million stars to about a trillion. • The galaxy in which we live is popularly called the 'Milky Way,' because that is what it looked like to the ancients. ...
... • 'Galaxies' are what we call the huge star clusters that inhabit our universe. • These clusters range in size from ten million stars to about a trillion. • The galaxy in which we live is popularly called the 'Milky Way,' because that is what it looked like to the ancients. ...
Star Clusters - Caltech Astronomy
... Associations are normally observed as widespread regions with an excess density of spectral type O and B stars (‘OB ASSOCIATIONS’) or T TAURI STARS (‘T associations’). In principle, there could be other types of association as well. It is not uncommon to find one or more open clusters at the core of ...
... Associations are normally observed as widespread regions with an excess density of spectral type O and B stars (‘OB ASSOCIATIONS’) or T TAURI STARS (‘T associations’). In principle, there could be other types of association as well. It is not uncommon to find one or more open clusters at the core of ...
A Star - Cloudy Nights
... bluish tint. The pair are about 410 light years distant and are separated by 4400 A.U. Mizar is a fine example of a double star system. This pair lies at a distance of 88 light years and are separated by 380 A.U. Observations indicate that it must take several thousand years for these two stars to ...
... bluish tint. The pair are about 410 light years distant and are separated by 4400 A.U. Mizar is a fine example of a double star system. This pair lies at a distance of 88 light years and are separated by 380 A.U. Observations indicate that it must take several thousand years for these two stars to ...