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5731. RVs and [Fe/H] of star members of NGC 6388
ID:
ivo://CDS.VizieR/J/ApJ/769/107
Title:
RVs and [Fe/H] of star members of NGC 6388
Short Name:
J/ApJ/769/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
By combining high spatial resolution and wide-field spectroscopy performed, respectively, with SINFONI and FLAMES at the ESO/VLT we measured the radial velocities of more than 600 stars in the direction of NGC 6388, a Galactic globular cluster which is suspected to host an intermediate-mass black hole. Approximately 55% of the observed targets turned out to be cluster members. The cluster velocity dispersion has been derived from the radial velocity of individual stars: 52 measurements in the innermost 2", and 276 stars located between 18" and 600". The velocity dispersion profile shows a central value of ~13km/s, a flat behavior out to ~60" and a decreasing trend outward. The comparison with spherical and isotropic models shows that the observed density and velocity dispersion profiles are inconsistent with the presence of a central black hole more massive than ~2000M_{sun}_. These findings are at odds with recent results obtained from integrated light spectra, showing a velocity dispersion profile with a steep central cusp of 23-25km/s at r<2" and suggesting the presence of a black hole with a mass of ~1.7x10^4^M_{sun}_. We also found some evidence of systemic rotation with amplitude A_rot_~8km/s in the innermost 2" (0.13pc), decreasing to A_rot_=3.2km/s at 18"<r<160".
5732. RVs and light curves for HATS-60-HATS-69
ID:
ivo://CDS.VizieR/J/AJ/157/55
Title:
RVs and light curves for HATS-60-HATS-69
Short Name:
J/AJ/157/55
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of 10 transiting extrasolar planets by the HATSouth survey. The planets range in mass from the super-Neptune HATS-62b, with M_p_<0.179 M_J_, to the super-Jupiter HATS-66b, with M_p_=5.33 M_J_, and in size from the Saturn HATS-69b, with R_p_=0.94 R_J_, to the inflated Jupiter HATS-67b, with R_p_=1.69 R_J_. The planets have orbital periods between 1.6092 days (HATS-67b) and 7.8180 days (HATS-61b). The hosts are dwarf stars with masses ranging from 0.89 M_{sun}_ (HATS-69) to 1.56 M_{sun}_ (HATS-64) and have apparent magnitudes between V=12.276+/-0.020 mag (HATS-68) and V=14.095+/-0.030 mag (HATS-66). The super-Neptune HATS-62b is the least massive planet discovered to date with a radius larger than Jupiter. Based largely on the Gaia DR2 distances and broadband photometry, we identify three systems (HATS-62, HATS-64, and HATS-65) as having possible unresolved binary star companions. We discuss in detail our methods for incorporating the Gaia DR2 observations into our modeling of the system parameters and into our blend analysis procedures.
5733. RVs and opt. photometry of the host star TOI-677
ID:
ivo://CDS.VizieR/J/AJ/159/145
Title:
RVs and opt. photometry of the host star TOI-677
Short Name:
J/AJ/159/145
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of TOI-677b, first identified as a candidate in light curves obtained within Sectors 9 and 10 of the Transiting Exoplanet Survey Satellite (TESS) mission and confirmed with radial velocities. TOI-677b has a mass of M_p_=1.236_-0.067_^+0.069^M_J_, a radius of R_P_=1.170{+/-}0.03R_J_, and orbits its bright host star (V=9.8mag) with an orbital period of 11.23660{+/-}0.00011d, on an eccentric orbit with e=0.435{+/-}0.024. The host star has a mass of M_*_=1.181{+/-}0.058M_{sun}_, a radius of R_*_=1.28_-0.03_^+0.03^R_{sun}_, an age of 2.92_-0.73_^+0.80^Gyr and solar metallicity, properties consistent with a main-sequence late-F star with T_eff_=6295{+/-}77K. We find evidence in the radial velocity measurements of a secondary long-term signal, which could be due to an outer companion. The TOI-677b system is a well-suited target for Rossiter-Mclaughlin observations that can constrain migration mechanisms of close-in giant planets.
5734. RVs and R-band obs. of the EB* V541 Cyg
ID:
ivo://CDS.VizieR/J/ApJ/836/177
Title:
RVs and R-band obs. of the EB* V541 Cyg
Short Name:
J/ApJ/836/177
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report new spectroscopic and photometric observations of the main-sequence, detached, eccentric, double-lined eclipsing binary V541Cyg (P=15.34d, e=0.468). Using these observations together with existing measurements, we determine the component masses and radii to better than 1% precision: M_1_=2.335_-0.013_^+0.017^M_{sun}_, M_2_=2.260_-0.013_^+0.016^M_{sun}_, R_1_=1.859_-0.009_^+0.012^R_{sun}_, and R_2_=1.808_-0.013_^+0.015^R_{sun}_. The nearly identical B9.5 stars have estimated effective temperatures of 10650+/-200K and 10350+/-200K. A comparison of these properties with current stellar evolution models shows excellent agreement at an age of about 190Myr and [Fe/H]~-0.18. Both components are found to be rotating at the pseudo-synchronous rate. The system displays a slow periastron advance that is dominated by general relativity (GR), and has previously been claimed to be slower than predicted by theory. Our new measurement, dot{omega}=0.859_-0.017_^+0.042^deg/century, has an 88% contribution from GR and agrees with the expected rate within the uncertainties. We also clarify the use of the gravity darkening coefficients in the light-curve fitting Eclipsing Binary Orbit Program (EBOP), a version of which we use here.
5735. RVs and RI-photometry of HATS-37 and HATS-38
ID:
ivo://CDS.VizieR/J/AJ/160/222
Title:
RVs and RI-photometry of HATS-37 and HATS-38
Short Name:
J/AJ/160/222
Date:
09 Mar 2022 22:00:00
Publisher:
CDS
Description:
We report the discovery of two transiting Neptunes by the HATSouth survey. The planet HATS-37Ab has a mass of 0.099{+/-}0.042M_Jup_ (31.5{+/-}13.4M{Earth}) and a radius of 0.606{+/-}0.016R_Jup_, and is on a P=4.3315day orbit around a V=12.266{+/-}0.030mag, 0.843_-0.012_^+0.017^M{odot} star with a radius of 0.877_-0.012_^+0.019^R{odot}. We also present evidence that the star HATS-37A has an unresolved stellar companion HATS-37B, with a photometrically estimated mass of 0.654{+/-}0.033M{odot}. The planet HATS-38b has a mass of 0.074{+/-}0.011M_Jup_ (23.5{+/-}3.5M{Earth}) and a radius of 0.614{+/-}0.017R_Jup_, and is on a P=4.3750day orbit around a V=12.411{+/-}0.030mag, 0.890_-0.012_^+0.016^M{odot} star with a radius of 1.105{+/-}0.016 R{odot}. Both systems appear to be old, with isochrone-based ages of 11.46_-1.45_^+0.79^Gyr, and 11.89{+/-}0.60Gyr, respectively. Both HATS-37Ab and HATS-38b lie in the Neptune desert and are thus examples of a population with a low occurrence rate. They are also among the lowest-mass planets found from ground-based wide-field surveys to date.
5736. RVs & V-band LCs of probable members of Cyg OB2
ID:
ivo://CDS.VizieR/J/ApJ/811/85
Title:
RVs & V-band LCs of probable members of Cyg OB2
Short Name:
J/ApJ/811/85
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the "Cygnus X" complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this l~=80{deg} sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33+/-0.17, 1.32+/-0.07, 1.44+/-0.18, and 1.32+/-0.13kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33+/-0.06kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4" visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.
5737. RV variability in SDSS dwarf carbon stars
ID:
ivo://CDS.VizieR/J/ApJ/877/44
Title:
RV variability in SDSS dwarf carbon stars
Short Name:
J/ApJ/877/44
Date:
21 Oct 2021
Publisher:
CDS
Description:
Dwarf carbon (dC) stars (main-sequence stars showing carbon molecular bands) were initially thought to be an oxymoron because only asymptotic giant branch (AGB) stars dredge carbon into their atmospheres. Mass transfer from a former AGB companion that has since faded to a white dwarf seems the most likely explanation. Indeed, a few types of giants known to show anomalous abundances- notably, the CH, Ba and CEMP-s stars-are known to have a high binary frequency. The dC stars may be the enhanced-abundance progenitors of most, if not all of these systems, but this requires demonstrating a high binary frequency for dCs. Here, for a sample of 240 dC stars targeted for repeat spectroscopy by the SDSS-IV's Time Domain Spectroscopic Survey, we analyze radial velocity (RV) variability to constrain the binary frequency and orbital properties. A handful of dC systems show large velocity variability (>100km/s). We compare the dCs to a control sample with a similar distribution of magnitude, color, proper motion, and parallax. Using Markov chain Monte Carlo methods, we use the measured {Delta}RV distribution to estimate the binary fraction and the separation distribution assuming both a unimodal and bimodal distribution. We find the dC stars have an enhanced binary fraction of 95%, consistent with them being products of mass transfer. These models result in mean separations of less than 1 au corresponding to periods on the order of 1 yr. Our results support the conclusion that dC stars form from close binary systems via mass transfer.
5738. RXJ1604.3-2130A griz and JHK light curves
ID:
ivo://CDS.VizieR/J/A+A/633/A37
Title:
RXJ1604.3-2130A griz and JHK light curves
Short Name:
J/A+A/633/A37
Date:
21 Oct 2021
Publisher:
CDS
Description:
RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk with respect to its face-on outer disk. We study the eclipses to constrain the inner disk properties. We use time-resolved photometry from the Rapid Eye Mount telescope and Kepler 2 data to study the multi-wavelength variability, and archival optical and IR data to track accretion, rotation, and changes in disk structure. The observations reveal details of the structure and matter transport through the inner disk. The eclipses show 5d quasi-periodicity, with the phase drifting in time and some periods showing increased/decreased eclipse depth and frequency. Dips are consistent with extinction by slightly processed dust grains in an inclined, irregularly-shaped inner disk locked to the star through two relatively stable accretion structures. The grains are located near the dust sublimation radius (~0.09au) at the corotation radius, and can explain the shadows observed in the outer disk. The total mass (gas and dust) required to produce the eclipses and shadows is a few % of a Ceres mass. Such amount of mass is accreted/replenished by accretion in days to weeks, which explains the variability from period to period. Spitzer and WISE variability reveal variations in the dust content in the innermost disk on a few years timescale, which is consistent with small imbalances (compared to the stellar accretion rate) in the matter transport from the outer to the inner disk. A decrease in the accretion rate is observed at the times of less eclipsing variability and low mid-IR fluxes, confirming this picture. The vsini=16km/s confirms that the star cannot be aligned with the outer disk, but is likely close to equator-on and to be aligned with the inner disk. This anomalous orientation is a challenge for standard theories of protoplanetary disk formation.
5739. RX J105453.3+552102 cluster SDSS photometry
ID:
ivo://CDS.VizieR/J/A+A/527/A143
Title:
RX J105453.3+552102 cluster SDSS photometry
Short Name:
J/A+A/527/A143
Date:
21 Oct 2021
Publisher:
CDS
Description:
The most accepted scenario for the origin of fossil groups is that they are galaxy associations in which the merging rate was fast and efficient. These systems have assembled half of their mass at early epoch of the Universe, subsequently growing by minor mergers, and therefore could contain a fossil record of the galaxy structure formation. We have started an observational project in order to characterize a large sample of fossil groups. In this paper we present the analysis of the fossil system RX J105453.3+552102.
5740. RX J2117.1+3412 (V2027 Cyg) light curves
ID:
ivo://CDS.VizieR/J/A+A/558/A63
Title:
RX J2117.1+3412 (V2027 Cyg) light curves
Short Name:
J/A+A/558/A63
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the effort to search for white dwarf p-mode oscillations in RX J2117.1+3412 (V2027 Cyg), a GW Vir star. The data were taken with Miosotys, a multi-fiber photometer, mounted on the 1.93-m telescope at Observatoire de Haute-Provence (OHP) with a 20-Hz cadence in May 2010 and June 2012. Two intriguing signatures at 1.2081Hz and 2.5852Hz were found at 3.8{sigma} and 3.5{sigma} significance levels, respectively. However, possible atmospheric effects cannot be ruled out. If these two features are not real, the 3{sigma} upper limit of the relative amplitude for the possible oscillations in the frequency range from 1 to 10Hz is estimated to be about 6x10^-4^. This is the first report in the literature for a p-mode oscillation search of GW Vir stars.