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- ID:
- ivo://CDS.VizieR/J/AJ/157/141
- Title:
- Radial velocity and light curves of WASP-190
- Short Name:
- J/AJ/157/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of WASP-190b, an exoplanet on a 5.37 day orbit around a mildly evolved F6 IV-V star with V=11.7, T_eff_=6400+/-100 K, M_*_=1.35+/-0.05 M_{sun}_, and R_*_=1.6+/-0.1 R_{sun}_. The planet has a radius of R_P_=1.15+/-0.09 R_Jup_ and a mass of M_P_=1.0+/-0.1 M_Jup_, making it a mildly inflated hot Jupiter. It is the first hot Jupiter confirmed via Doppler tomography with an orbital period of >5 days. The orbit is also marginally misaligned with respect to the stellar rotation, with {lambda}=21{deg}+/-6{deg} measured using Doppler tomography.
- ID:
- ivo://CDS.VizieR/J/AJ/150/12
- Title:
- Radial velocity of HD 33643
- Short Name:
- J/AJ/150/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of 1.28+/-0.18M_J_, radius of 1.533^+0.046^_-0.047_R_J_, and an orbital period of 2.7347749+/-0.0000039days. The bright host star (HD33643; KELT-7) is an F-star with V=8.54, T_eff_=6789^+50^_-49_K, [Fe/H]=0.139^+0.075^_-0.081_, and logg=4.149+/-0.019. It has a mass of 1.535^+0.066^_-0.054_M_{Sun}_, a radius of 1.732^+0.043^_-0.045_R_{Sun}_, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which Kilodegree Extremely Little Telescope (KELT) has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star (73+/-0.5km/s) results in a Rossiter-McLaughlin effect with an unusually large amplitude of several hundred m/s. We find that the orbit normal of the planet is likely to be well-aligned with the stellar spin axis, with a projected spin-orbit alignment of {lambda}=9.7{deg}+/-5.2{deg}. This is currently the second most rapidly rotating star to have a reflex signal (and thus mass determination) due to a planetary companion measured.
- ID:
- ivo://CDS.VizieR/J/AJ/161/235
- Title:
- Radial velocity of TOI-201
- Short Name:
- J/AJ/161/235
- Date:
- 16 Mar 2022 11:46:40
- Publisher:
- CDS
- Description:
- We present the confirmation of the eccentric warm giant planet TOI-201b, first identified as a candidate in Transiting Exoplanet Survey Satellite photometry (Sectors 1-8, 10-13, and 27-28) and confirmed using ground-based photometry from Next Generation Transit Survey and radial velocities from FEROS, HARPS, CORALIE, and Minerva-Australis. TOI-201b orbits a young (0.87_-0.49_^+0.46^Gyr) and bright (V=9.07mag) F-type star with a 52.9781day period. The planet has a mass of 0.42_-0.03_^+0.05^M_J_, a radius of 1.008_-0.015_^+0.012^R_J_, and an orbital eccentricity of 0.28_-0.09_^+0.06^; it appears to still be undergoing fairly rapid cooling, as expected given the youth of the host star. The star also shows long-term variability in both the radial velocities and several activity indicators, which we attribute to stellar activity. The discovery and characterization of warm giant planets such as TOI-201b are important for constraining formation and evolution theories for giant planets.
- ID:
- ivo://CDS.VizieR/J/ApJ/709/159
- Title:
- Relative Ic photometry of WASP-17
- Short Name:
- J/ApJ/709/159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the transiting giant planet WASP-17b, the least-dense planet currently known. It is 1.6 Saturn masses, but 1.5-2 Jupiter radii, giving a density of 6%-14% that of Jupiter. WASP-17b is in a 3.7 day orbit around a sub-solar metallicity, V=11.6, F6 star. Preliminary detection of the Rossiter-McLaughlin effect suggests that WASP-17b is in a retrograde orbit ({lambda}~-150{deg}), indicative of a violent history involving planet-planet or star-planet scattering. WASP-17b's bloated radius could be due to tidal heating resulting from recent or ongoing tidal circularization of an eccentric orbit, such as the highly eccentric orbits that typically result from scattering interactions. It will thus be important to determine more precisely the current orbital eccentricity by further high-precision radial velocity measurements or by timing the secondary eclipse, both to reduce the uncertainty on the planet's radius and to test tidal-heating models. Owing to its low surface gravity, WASP-17b's atmosphere has the largest scale height of any known planet, making it a good target for transmission spectroscopy.
- ID:
- ivo://CDS.VizieR/J/ApJ/595/1206
- Title:
- ROSAT view of Hipparcos F stars
- Short Name:
- J/ApJ/595/1206
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For a set of 11900 F stars that have uvby photometry and are in the Hipparcos (Cat. <I/239>) catalog, we have found 1980 X-ray counterparts (~17%) in the ROSAT All-Sky Surveys (RASS, Cat. <IX/10> and <IX/29>). In this paper we analyze X-ray properties of these ROSAT F stars and compare that sample with the entire set of our F stars.
- ID:
- ivo://CDS.VizieR/J/A+A/398/647
- Title:
- Rotational velocities of F and G stars
- Short Name:
- J/A+A/398/647
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed study of rotation and differential rotation analyzing high resolution high S/N spectra of 142 F-, G- and early K-type field stars. Using Least Squares Deconvolution we obtain broadening profiles for our sample stars and use the Fourier transform method to determine projected rotational velocities vsini. Distributions of rotational velocities and periods are studied in the HR-diagram. For a subsample of 32 stars of spectral type F0-G0 we derive the amount of differential rotation. We find evidence for differential rotation in ten of the 32 stars. The observations were done with the ESO 3.6m telescope at La Silla, Chile, in October 2000, October 2001 and April 2002. The CES instrument (resolution 235000) was used, in the wavelength regions 577-581nm and 322.5-627nm.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/545
- Title:
- Rotational velocities of F dwarfs
- Short Name:
- J/A+AS/118/545
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- table4 contains rotational velocities for 177 dwarfs with spectral types between A7 en G2.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/277
- Title:
- Rotation and binary rate among giant F stars
- Short Name:
- J/A+AS/127/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have tested the hypothesis of Berthet (1991A&A...251..171B) which foresees that Am stars become giant metallic A and F stars (defined by an enhanced value of the blanketing parameter {delta}m2 of the Geneva photometry) when they evolved. If this hypothesis is right, Am and metallic A-FIII stars need to have the same rate of binaries and a similar distribution of vsini. From our new spectroscopic data and from vsini and radial velocities in the literature, we show that it is not the case. The metallic giant stars are often fast rotators with vsini larger than 100 km/s, while the maximum rotational velocity for Am stars is about 100 km/s. The rate of tight binaries with periods less than 1000 days is less than 30 % among metallic giants, which is incompatible with the value of 75 % for Am stars (Abt & Levy, 1985ApJS...59..229A). Therefore, the simplest way to explain the existence of giant metallic F stars is to suggest that all normal A and early F stars might go through a short "metallic" phase when they are finishing their life on the main sequence. Besides, it is shown that only giant stars with spectral type comprised between F0 and F6 may have a really enhanced {delta}m2 value, while all A-type giants seem to be normal.
- ID:
- ivo://CDS.VizieR/J/A+A/412/813
- Title:
- Rotation in F-stars
- Short Name:
- J/A+A/412/813
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained high quality spectra of 135 stars of spectral types F and later and derived "overall" broadening functions in selected wavelength regions utilizing a Least Squares Deconvolution (LSD) procedure. Precision values of the projected rotational velocity vsini were derived from the first zero of the Fourier transformed profiles and the shapes of the profiles were analyzed for effects of differential rotation. The broadening profiles of 70 stars rotating faster than vsini=45km/s show no indications of multiplicity nor of spottedness. In those profiles we used the ratio of the first two zeros of the Fourier transform q2/q1 to search for deviations from rigid rotation. In the vast majority the profiles were found to be consistent with rigid rotation. Five stars were found to have flat profiles probably due to cool polar caps, in three stars cuspy profiles were found. Two out of those three cases may be due to extremely rapid rotation seen pole on, only in one case (vsini=52km/s) solar-like differential rotation is the most plausible explanation for the observed profile. These results indicate that the strength of differential rotation diminishes in stars rotating as rapidly as vsini>50km/s.
