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Titolo:
Direct multi-wavelength limb-darkening measurements of three late-type giants with the Navy Prototype Optical Interferometer
Autore:
Wittkowski, M; Hummel, CA; Johnston, KJ; Mozurkewich, D; Hajian, AR; White, NM;
Indirizzi:
USN Observ, Washington, DC 20392 USA USN Observ Washington DC USA 20392USN Observ, Washington, DC 20392 USA USN, Res Lab, Code 7210, Washington, DC 20375 USA USN Washington DC USA 20375 Res Lab, Code 7210, Washington, DC 20375 USA Lowell Observ, Flagstaff, AZ 86001 USA Lowell Observ Flagstaff AZ USA 86001 well Observ, Flagstaff, AZ 86001 USA USRA, Washington, DC 20024 USA USRA Washington DC USA 20024USRA, Washington, DC 20024 USA
Titolo Testata:
ASTRONOMY & ASTROPHYSICS
fascicolo: 3, volume: 377, anno: 2001,
pagine: 981 - 993
SICI:
1432-0746(200110)377:3<981:DMLMOT>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
EFFECTIVE TEMPERATURE SCALE; SPECKLE-MASKING INTERFEROMETRY; ANGULAR DIAMETER MEASUREMENTS; STELLAR INTERFEROMETER; STARS; RADII; SUPERGIANTS; MODEL; MIRA; TELESCOPE;
Keywords:
techniques : interferometric; techniques : high angular resolution; stars : fundamental parameters; stars : atmospheres; stars : late-type;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Wittkowski, M USN Observ, AD5,3450 Massachusetts Ave NW, Washington, DC 20392 USA USN Observ AD5,3450 Massachusetts Ave NW Washington DC USA 20392
Citazione:
M. Wittkowski et al., "Direct multi-wavelength limb-darkening measurements of three late-type giants with the Navy Prototype Optical Interferometer", ASTRON ASTR, 377(3), 2001, pp. 981-993

Abstract

We present direct measurements of the limb-darkened intensity profiles of the late-type giant stars HR5299, HR7635, and HR8621 obtained with the NavyPrototype Optical Interferometer (NPOI) at the Lowell Observatory. A triangle of baselines with lengths of 18.9 m, 22.2 m, and 37.5 m was used. We utilized squared visibility amplitudes beyond the first minimum, as well as triple amplitudes and phases in up to 10 spectral channels covering a wavelength range of similar to 650 nm to similar to 850 nm. We find that our datacan best be described by featureless symmetric limb-darkened disk models while uniform disk and fully darkened disk models can be rejected. We derivehigh-precision angular limb-darkened diameters for the three stars of 7.44mas +/- 0.11 mas, 6.18 mas +/- 0.07 mas, and 6.94 mas +/- 0.12 mas, respectively. Using the HIPPARCOS parallaxes, we determine linear limb-darkened radii of 114 R. +/- 13 R., 56 R. +/- 4 R., and 98 R. +/- 9 R., respectively. We compare our data to a grid of Kurucz stellar model atmospheres, with them derive the effective temperatures and surface gravities without additional information, and find agreement with independent estimates derived from empirical calibrations and bolometric fluxes. This confirms the consistencyof model predictions and direct observations of the limb-darkening effect.

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Documento generato il 28/09/20 alle ore 01:49:13