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Related papers: Angular Sizes and Effective Temperatures of O-type…

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The bright, well-known K5 giant Aldebaran, alpha Tau, is probably the star with the largest number of direct angular diameter determinations, achieved over a long time by several authors using various techniques. In spite of this wealth of…

Astrophysics · Physics 2009-11-10 A. Richichi , V. Roccatagliata

With a possible angular resolution down to 0.1-0.2 millisecond of arc using the 330 m baselines and the access to the 600-900 nm spectral domain, the CHARA Array is ideally configured for focusing on precise and accurate fundamental…

Past studies based on optical spectroscopy suggest that the five $\omega$ Cen pulsators form a rather homogeneous group of hydrogen-rich subdwarf O stars with effective temperatures of around 50 000 K. This places the stars below the red…

Solar and Stellar Astrophysics · Physics 2017-04-12 M. Latour , S. K. Randall , P. Chayer , G. Fontaine , A. Calamida , J. Ely , T. M. Brown , W. Landsman

We present infrared interferometric angular size measurements for the A7IV-V star Altair which indicate a non-circular projected disk brightness distribution. Given the known rapid rotation of this star, we model the data as arising from an…

The Narrabri intensity interferometer was successfully used until 1974 to observe 32 stars, all brighter than B=+2.5, among which some were found to have an angular diameter as small as 0.41+/-0.03 milli-arc-seconds (mas). The technique was…

Astrophysics · Physics 2007-05-23 S. LeBohec , J. Holder

Atmospheric turbulence is an important limit to high angular resolution in astronomy. Interferometry resolved this issue by filtering the incoming light with single-mode fibers. Thanks to this technique, we obtained with the IOTA…

Instrumentation and Methods for Astrophysics · Physics 2010-03-18 Sylvestre Lacour

The most complete catalogue of nearby stars (Gliese and Jarheiss, 1991) has been used to search for the stars whose photospheric thermal emission can be detected by the future millimeter array ALMA. We found that 446 nearby stars with…

Astrophysics · Physics 2007-05-23 Jean-Francois Lestrade

Determining the physical properties of microlensing events depends on having accurate angular sizes of the source star. Using long-baseline optical interferometry we are able to measure the angular sizes of nearby stars with uncertainties…

Solar and Stellar Astrophysics · Physics 2017-12-06 Arthur D. Adams , Tabetha S. Boyajian , Kaspar von Braun

Two red supergiants of the Per OB1 association, RS Per and T Per, have been observed in H band using the MIRC instrument at the CHARA array. The data show clear evidence of departure from circular symmetry. We present here new techniques…

MIRC-X is a six telescope beam combiner at the CHARA array that works in J and H wavelength bands and provides an angular resolution equivalent to a $B$=331m diameter telescope. The legacy MIRC combiner has delivered outstanding results in…

We find the angular diameter of R Doradus to be 57 +/- 5 mas, exceeding that of Betelgeuse and implying that R Dor is larger in apparent size than every star except the Sun. R Dor is shown to be closely related to the Mira variables. We…

Reliable prediction of stellar diameters, particularly angular diameters, is a useful and necessary tool for the increasing number of milliarcsecond resolution studies being carried out in the astronomical community. A new and accurate…

Astrophysics · Physics 2008-11-26 G. T. van Belle

A crucial issue in star formation is to understand the physical mechanism by which mass is accreted onto and ejected by a young star. The visible spectrometer VEGA on the CHARA array can be an efficient means of probing the structure and…

Context. Late O-type stars at luminosities $\log L/L_\odot \lesssim 5.2$ show weak winds with mass-loss rates lower than 10$^{-8} M_\odot$ yr$^{-1}$. This implies that their photospheric layers are not strongly affected by the stellar wind.…

Solar and Stellar Astrophysics · Physics 2023-03-08 Patrick Aschenbrenner , Norbert Przybilla , Keith Butler

Alpha Centauri A is the closest solar-type star to the Sun and offers an excellent opportunity to detect the thermal emission of a mature planet heated by its host star. The MIRI coronagraph on JWST can search the 1-3 AU (1"-2") region…

Cool stars on the main sequence generate X-rays from coronal activity, powered by a convective dynamo. With increasing temperature, the convective envelope becomes smaller and X-ray emission fainter. We present Chandra/HRC-I observations of…

Solar and Stellar Astrophysics · Physics 2022-06-22 Hans Moritz Günther , Carl Melis , J. Robrade , P. C. Schneider , Scott J. Wolk , Rakesh K. Yadav

We present spectroscopic and interferometric measurements for a sample of nine K giant stars. These targets are of particular interest because they are slated for stellar oscillation observations. Our improved parameters will directly…

Solar and Stellar Astrophysics · Physics 2016-09-21 Ellyn K. Baines , Michaela P. Döllinger , Eike W. Guenther , Artie P. Hatzes , Marie Hrudkovu , Gerard T. van Belle

The study of Young Stellar Objects (YSOs) is one of the most exciting topics that can be undertaken by long baseline optical interferometry. The magnitudes of these objects are at the edge of capabilities of current optical interferometers,…

Astrophysics · Physics 2009-11-07 Fabien Malbet

The Chandra Carina Complex contains 200 known O- and B type stars. The Chandra survey detected 68 of the 70 O stars and 61 of 127 known B0-B3 stars. We have assembled a publicly available optical/X-ray database to identify OB stars that…

Context. Red giant branch (RGB) stars are very bright objects in galaxies and are often used as standard candles. Interferometry is the ideal tool to characterize the dynamics and morphology of their atmospheres. Aims. We aim at precisely…

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