Comparison of Stellar Angular Diameters from the NPOI, the Mark III Optical Interferometer, and the Infrared Flux Method

Nordgren, Tyler E.; Sudol, Jeffrey J.; Mozurkewich, David

doi:10.1086/323546

Cited by 86 publications

(83 citation statements)

References 13 publications

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“…Still, the spectrophotometric observations could be affected by the significant magnetic activity exhibited by ζ And. The LD diameter of μ Peg obtained here is consistent with the earlier interferometric measurements of θ LD = 2.53 ± 0.09 mas obtained with the NPOI and θ LD = 2.49 ± 0.04 mas obtained with the Mark III interferometers (Nordgren et al 2001;and Mozurkewich et al 2003), increasing the confidence in the results presented here.…”

Section: Analysis Of Interferometric Datasupporting

confidence: 92%

“…For all the observations, AMBER was used in the low-resolution mode at J, H, and K passbands, giving a resolving power (λ/Δλ) of ∼35 and recording data between In addition to ζ And, a circular check star was observed every night. For this μ Peg was chosen because it is at a similar position on the sky as ζ And and it is expected to have a similar angular diameter (Θ LD = 2.50 ± 0.04 mas; Nordgren et al 2001;Mozurkewich et al 2003). Observations of ζ And and μ Peg were interleaved with observations of the interferometric calibration stars θ Psc (K1 III, K = 1.86, Θ LD = 2.00 ± 0.02 mas), 41 Psc (K3 III, K = 2.43, Θ LD = 1.81 ± 0.02 mas), HD 7087 (G9 III, K = 2.48, Θ LD = 1.59 ± 0.02 mas), and HD 15694 (K3 III, K = 2.48, Θ LD = 1.77 ± 0.02 mas).…”

Section: Optical Interferometrymentioning

confidence: 99%

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Ellipsoidal primary of the RS CVn binaryζ Andromedae

Korhonen

Wittkowski

Kővári³

et al. 2010

A&A

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Aims. We have obtained high-resolution spectroscopy, optical interferometry, and long-term broad band photometry of the ellipsoidal primary of the RS CVn-type binary system ζ And. These observations are used to obtain fundamental stellar parameters and to study surface structures and their temporal evolution. Methods. Temperature maps of the stellar surface were obtained from high-resolution spectra with Doppler imaging techniques. These spectra were also used to investigate the chromospheric activity using the Hα line and to correlate it with the photospheric activity. The possible cyclicity in the spot activity was investigated from the long-term broad band photometry. Optical interferometry was obtained during the same time period as the high-resolution spectra. These observations were used to derive the size and fundamental parameters of ζ And. Results. Based on the optical interferometry the apparent limb darkened diameter of ζ And is 2.55 ± 0.09 mas using a uniform disk fit. The expected ∼4% maximum difference between the long and short axes of the ellipsoidal stellar surface cannot be confirmed from the current data which have 4% errors. The Hipparcos distance and the limb-darkened diameter obtained with a uniform disk fit give stellar radius of 15.9 ± 0.8 R , and combined with bolometric luminosity, it implies an effective temperature of 4665 ± 140 K. The temperature maps obtained from Doppler imaging show a strong belt of equatorial spots and hints of a cool polar cap. The equatorial spots show a concentration around the phase 0.75, i.e., 0.25 in phase from the secondary, and another concentration spans the phases 0.0-0.4. This spot configuration is reminiscent of the one seen in the earlier published temperature maps of ζ And. Investigation of the Hα line reveals both prominences and cool clouds in the chromosphere. These features do not seem to have a clearly preferred location in the binary reference frame, nor are they strongly associated with the cool photospheric spots. The investigation of the long-term photometry spanning 12 years shows hints of a spot activity cycle, which is also implied by the Doppler images, but the cycle length cannot be reliably determined from the current data.

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Section: Analysis Of Interferometric Datasupporting

confidence: 92%

Section: Optical Interferometrymentioning

confidence: 99%

Ellipsoidal primary of the RS CVn binaryζ Andromedae

Korhonen

Wittkowski

Kővári³

et al. 2010

A&A

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“…Mass Age (2003) 7.95±0.09 Nordgren et al (2001) 7.97±0.11 Nordgren et al (2001) 8.035±0.08 Mozurkewich et al (1991) 9.26±0.15 Shao et al (1988) 7.90±0.31 di Benedetto & Rabbia (1987) (2016) 3.722±0.071 Mozurkewich et al (2003) 3.34±0.07 Nordgren et al (2001) 3.68±0.05 Nordgren et al (2001) 148856 3.472±0.008 3.462±0.035 Mozurkewich et al (2003) 3.53±0.08 Nordgren et al (2001) 3.51±0.05 Nordgren et al (2001) 150997 2.493±0.018 2.624±0.034 Mozurkewich et al (2003) 2.50±0.08 Nordgren et al (2001) 2.64±0.04 Nordgren et al (2001) 2.42±0.07 Nordgren et al (1999) 156283 5.519±0.011 5.275±0.067 Mozurkewich et al (2003) 5.26±0.06 Nordgren et al (2001) 5.27±0.07 Nordgren et al (2001) 5.20±0.03 Nordgren et al (1999) (2016) 2.12±0.02 Ligi et al (2012) 2.041±0.043 Baines et al (2010) 172167 3.280±0.016 2.930±0.007 Monnier et al (2012) 3.08±0.03 * Mourard et al (2009) 3.202±0.005 * Absil et al (2006) 3.329±0.006 Aufdenberg et al (2006) 3.225±0.032 Mozurkewich et al (2003) 3.28±0.01 Ciardi et al (2001) Mozurkewich et al (2003) 3.11±0.04 Nordgren et al (2001) 3.20±0.05 Nordgren et al (2001) 3.08±0.03 Nordgren et al (1999) Note- * No LD diameter was provided, therefore we list the UD diameter here. Figure 4 shows a graphical representation of this table.…”

Section: Targetmentioning

confidence: 99%

Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer

et al. 2017

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We present the fundamental properties of 87 stars based on angular diameter measurements from the Navy Precision Optical Interferometer, 36 of which have not been measured previously using interferometry. Our sample consists of 5 dwarfs, 3 subgiants, 69 giants, 3 bright giants, and 7 supergiants, and span a wide range of spectral classes from B to M. We combined our angular diameters with photometric and distance information from the literature to determine each star's physical radius, effective temperature, bolometric flux, luminosity, mass, and age.

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“…Moreover, the direct application of the SBC relation to Cepheids was done by Fouque & Gieren (1997) and Di Benedetto (1998). Later, 27 stars were measured by NPOI and Mark III optical interferometers and the derived high precision angular diameters were published by Nordgren et al (2001) and Mozurkewich et al (2003), respectively. Finally, using a compilation of 29 dwarfs and subgiant (including the sun) in the 0.0 ≤ (V − K) 0 ≤ 6.0 color range, Kervella et al (2004) calibrated for the first time a linear SBC relation with an intrinsic dispersion of 0.02 mag or 1% in terms of angular diameter.…”

Section: A Revised Sbc Relation For Late-and Early-type Starsmentioning

confidence: 99%

Improving the surface brightness-color relation for early-type stars using optical interferometry

Challouf

Nardetto

Mourard

et al. 2014

A&A

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Context. The method of distance determination of eclipsing binaries consists in combining the radii of both components determined from spectro-photometric observations with their respective angular diameters derived from the surface brightness-color relation (SBC). However, the largest limitation of the method comes from the uncertainty on the SBC relation: about 2% for late-type stars (or 0.04 magnitude) and more than 10% for early-type stars (or 0.2 mag). Aims. The aim of this work is to improve the SBC relation for early-type stars in the −1 ≤ V − K ≤ 0 color domain, using optical interferometry. Methods. Observations of eight B-and A-type stars were secured with the VEGA/CHARA instrument in the visible. The derived uniform disk angular diameters were converted into limb darkened angular diameters and included in a larger sample of 24 stars, already observed by interferometry, in order to derive a revised empirical relation for O, B, A spectral type stars with a V − K color index ranging from −1 to 0. We also took the opportunity to check the consistency of the SBC relation up to V − K 4 using 100 additional measurements. Results. We determined the uniform disk angular diameter for the eight following stars: γ Ori, ζ Per, 8 Cyg, ι Her, λ Aql, ζ Peg, γ Lyr, and δ Cyg with V − K color ranging from −0.70 to 0.02 and typical precision of about 1.5%. Using our total sample of 132 stars with V − K colors index ranging from about −1 to 4, we provide a revised SBC relation. For late-type stars (0 ≤ V − K ≤ 4), the results are consistent with previous studies. For early-type stars (−1 ≤ V − K ≤ 0), our new VEGA/CHARA measurements combined with a careful selection of the stars (rejecting stars with environment or stars with a strong variability), allows us to reach an unprecedented precision of about 0.16 magnitude or 7% in terms of angular diameter. Conclusions. We derive for the first time a SBC relation for stars between O9 and A3, which provides a new and reliable tool for the distance scale calibration.

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Comparison of Stellar Angular Diameters from the NPOI, the Mark III Optical Interferometer, and the Infrared Flux Method

Cited by 86 publications

References 13 publications

Ellipsoidal primary of the RS CVn binaryζ Andromedae

Ellipsoidal primary of the RS CVn binaryζ Andromedae

Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer

Improving the surface brightness-color relation for early-type stars using optical interferometry

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