Stars in the Making

Payne-Gaposchkin, Cecilia

doi:10.4159/harvard.9780674423794

Cited by 20 publications

(22 citation statements)

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“…Van den Hoven van Genderen (1939) refined the orbital period using a 914-point photographic light curve, but stated that the period should be doubled even though there was no clear evidence that adjacent minima had different depths. Gaposchkin (1952Gaposchkin ( , 1953 published a photographic light curve containing over one thousand points and found an orbital period of 1.3277504 d. His estimated masses and radii are quite close to the values we measure below.…”

Section: Dw Carinaesupporting

confidence: 84%

Absolute dimensions of eclipsing binaries

Southworth

Clausen

2006

A&A

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Context. The study of detached eclipsing binaries which are members of stellar clusters is is a powerful way of determining the properties of the cluster and of constraining the physical ingredients of theoretical stellar evolutionary models. Aims. DW Carinae is a close but detached early B-type eclipsing binary in the young open cluster Collinder 228. We have measured accurate physical properties of the components of DW Car (masses and radii to 1%, effective temperatures to 0.02 dex) and used these to derive the age, metallicity and distance of Collinder 228. Methods. The rotational velocities of both components of DW Car are high, so we have investigated the performance of doubleGaussian fitting, one-and two-dimensional cross-correlation and spectral disentangling for deriving spectroscopic radial velocites in the presence of strong line blending. Gaussian and cross-correlation analyses require substantial corrections for the effects of line blending, which are only partially successful for cross-correlation. Spectral disentangling is to be preferred because it does not assume anything about the shapes of spectral lines, and is not significantly affected by blending. However, it suffers from a proliferation of local minima in the least-squares fit. We show that the most reliable radial velocities are obtained using spectral disentangling constrained by the results of Gaussian fitting. Complete Strömgren uvby light curves have been obtained and accurate radii have been measured from them by modelling the light curves using the Wilson-Devinney program. This procedure also suffers from the presence of many local minima in parameter space, so we have constrained the solution using an accurate spectroscopic light ratio. The effective temperatures and reddening of the system have been found from Strömgren photometric calibrations. Results. The mass and radius of DW Car A are M A = 11.34 ± 0.12 M and R A = 4.558 ± 0.045 R . The values for DW Car B are M B = 10.63 ± 0.14 M and R B = 4.297 ± 0.055 R . Strömgren photometric calibrations give effective temperatures of T eff A = 27 900 ± 1000 K and T eff B = 26 500 ± 1000 K, and a reddening of E b−y = 0.18 ± 0.02, where the quoted uncertainties include a contribution from the intrinsic uncertainty of the calibrations. The membership of DW Car in Cr 228 allows us to measure the distance, age and chemical composition of the cluster. We have used empirical bolometric corrections to calculate a distance modulus of 12.24 ± 0.12 mag for DW Car, which is in agreement with, and more accurate than, literature values. A comparison between the properties of DW Car and the predictions of recent theoretical evolutionary models is undertaken in the mass-radius and mass-T eff diagrams. The model predictions match the measured properties of DW Car for an age of about 6 Myr and a fractional metal abundance of Z ≈ 0.01.

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Section: Dw Carinaesupporting

confidence: 84%

Absolute dimensions of eclipsing binaries

Southworth

Clausen

2006

A&A

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“…UU Aquarii (UU Aqr: V:13.5) was identified as a variable star early in this century (Beljawsky 1926). As observations of UU Aqr have been accumulated, its classification has evolved from a long-period semi-regular variable (Payne-Gaposchkin 1952), to a low Ṁ , optically thin disc, dwarf-nova type CV (Volkov, Shugarov & Seregina 1986), to a high Ṁ , optically thick disc, nova-like CV (Diaz & Steiner 1991, henceforth DS91;Baptista, Steiner & Cieslinski 1994, henceforth BSC94). Volkov et al (1986) and Goldader & Garnavich (1989) observed deep (:1.5 mag) eclipses in UU Aqr, and established an orbital period of P orb :0.163 579 089(61) d (:3.93 h).…”

Section: Introductionmentioning

confidence: 99%

Observations of the SW Sextantis star UU Aquarii

Hoard

Still

Szkody

et al. 1998

Monthly Notices of the Royal Astronomical Society

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A B S T R A C TWe present 14 nights of medium resolution (1-2Å) spectroscopy of the eclipsing cataclysmic variable UU Aquarii obtained during a high accretion state in 1995 August-October. UU Aqr appears to be an SW Sextantis (SW Sex) star, as noted by Baptista, Steiner & Horne, and we discuss its spectroscopic behaviour in the context of the SW Sex phenomenon. Emission-line equivalent width curves, Doppler tomography, and line profile simulation provide evidence for the presence of a bright spot at the impact site of the accretion stream with the edge of the disc, and a non-axisymmetric, vertically and azimuthally extended absorbing structure in the disc. The absorption has maximum depth in the emission lines around orbital phase 0.8, but is present from :0.4 to :0.95. An origin is explored for this absorbing structure (as well as for the other spectroscopic behaviour of UU Aqr) in terms of the explosive impact of the accretion stream with the disc.

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“…UU Aquarii (V ≈ 13.5) was identified as a variable star early in this century (Beljawsky 1926). As observations of UU Aqr have been accumulated, its classification has evolved from a long-period semi-regular variable (Payne-Gaposchkin 1952), to a lowṀ , optically thin disk, dwarf nova type CV (Volkov, Shugarov, & Seregina 1986), to a highṀ , optically thick disk, novalike CV (Diaz & Steiner 1991, henceforth DS91;Baptista, Steiner, & Cieslinski 1994, henceforth BSC94). Volkov et al (1986) and Goldader & Garnavich (1989) observed deep (≈ 1.5 mag) eclipses in UU Aqr, and established an orbital period of P orb = 0.163579089(61) d (≈ 3.93 h).…”

Section: Introductionmentioning

confidence: 99%

Observations of the SW Sextantis star UU Aquarii

Hoard

Still

Szkody

et al. 1998

Monthly Notices RAS

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We present 14 nights of medium resolution (1-2Å) spectroscopy of the eclipsing cataclysmic variable UU Aquarii obtained during a high accretion state in 1995 August-October. UU Aqr appears to be an SW Sextantis star, as noted by Baptista, Steiner, & Horne (1996), and we discuss its spectroscopic behavior in the context of the SW Sex phenomenon. Emission line equivalent width curves, Doppler tomography, and line profile simulation provide evidence for the presence of a bright spot at the impact site of the accretion stream with the edge of the disk, and a non-axisymmetric, vertically-and azimuthally-extended absorbing structure in the disk. The absorption has maximum depth in the emission lines around orbital phase 0.8, but is present from φ ≈ 0.4 to φ ≈ 0.95. An origin is explored for this absorbing structure (as well as the other spectroscopic behavior of UU Aqr) in terms of the explosive impact of the accretion stream with the disk.

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Stars in the Making

Cited by 20 publications

References 0 publications

Absolute dimensions of eclipsing binaries

Absolute dimensions of eclipsing binaries

Observations of the SW Sextantis star UU Aquarii

Observations of the SW Sextantis star UU Aquarii

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