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5441. Radial velocities of 108 stars in Ruprecht 147
ID:
ivo://CDS.VizieR/J/AJ/145/134
Title:
Radial velocities of 108 stars in Ruprecht 147
Short Name:
J/AJ/145/134
Date:
21 Oct 2021
Publisher:
CDS
Description:
Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H]=+0.07+/-0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g'-i') and Two Micron All Sky Survey (J-K_S_) color-magnitude diagrams, using the {tau}^2^ maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t=2.5+/-0.25Gyr, m-M=7.35+/-0.1, and A_V_=0.25+/-0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3Gyr and 3.25Gyr, respectively. At ~300pc and ~3Gyr, Ruprecht 147 is by far the oldest nearby star cluster.
5442. Radial velocities of TOI-1728 with HPF
ID:
ivo://CDS.VizieR/J/ApJ/899/29
Title:
Radial velocities of TOI-1728 with HPF
Short Name:
J/ApJ/899/29
Date:
14 Mar 2022 09:03:00
Publisher:
CDS
Description:
We confirm the planetary nature of TOI-1728b using a combination of ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with the Habitable-zone Planet Finder. TOI-1728 is an old, inactive M0 star with Teff=3980_-32_^+31^K, which hosts a transiting super-Neptune at an orbital period of ~3.49days. Joint fitting of the radial velocities and TESS and ground-based transits yields a planetary radius of 5.05_-0.17_^+0.16^ R{Earth}, mass 26.78_-5.13_^+5.43^M{Earth}, and eccentricity 0.057_-0.039_^+0.054^. We estimate the stellar properties, and perform a search for He 10830{AA} absorption during the transit of this planet and claim a null detection with an upper limit of 1.1% with 90% confidence. A deeper level of He 10830{AA} absorption has been detected in the planet atmosphere of GJ3470b, a comparable gaseous planet. TOI-1728b is the largest super-Neptune-the intermediate subclass of planets between Neptune and the more massive gas-giant planets-discovered around an M-dwarf. With its relatively large mass and radius, TOI-1728 represents a valuable data point in the M-dwarf exoplanet mass-radius diagram, bridging the gap between the lighter Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. With a low bulk density of 1.14_-0.24_^+0.26^g/cm^3^, and orbiting a bright host star (J~9.6, V~12.4), TOI-1728b is also a promising candidate for transmission spectroscopy both from the ground and from space, which can be used to constrain planet formation and evolutionary models.
5443. Radial velocities of UCOs in Fornax
ID:
ivo://CDS.VizieR/J/A+A/383/823
Title:
Radial velocities of UCOs in Fornax
Short Name:
J/A+A/383/823
Date:
21 Oct 2021
Publisher:
CDS
Description:
The relation between the Ultra Compact Objects (hereafter UCOs) recently discovered in the Fornax cluster (Drinkwater et al., 2000PASA...17..227D; Hilker et al., 1999, Cat. <J/A+AS/134/75>) and the brightest globular clusters associated with the central galaxy NGC 1399 has been investigated. A spectroscopic survey on compact objects in the central region of the Fornax cluster was carried out with the 2.5 m du Pont telescope (LCO) at Las Campanas, in the three nights of 2000/12/30 to 2001/01/01. The magnitude limit was approx. V=21 mag, the spectral resolution approx. 4{AA}. UCOs and the bright NGC 1399 globular clusters with similar brightness were inspected. 12 GCs from the bright end of the globular cluster luminosity function have been identified as Fornax members. Eight are new members, four were known as members from before.
5444. Radial velocities of 2 VY Sculptoris-type CV stars
ID:
ivo://CDS.VizieR/J/AJ/156/231
Title:
Radial velocities of 2 VY Sculptoris-type CV stars
Short Name:
J/AJ/156/231
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report observations of the known cataclysmic variable star (CV) V704 And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RX J2338+431 is a heretofore-neglected CV. Photometric and spectroscopic observations from MDM Observatory show both systems to be nova-like variables that exhibit dips of 4-5 mag from their mean brightnesses, establishing them as members of the VY Scl subclass. From high-state emission-line radial velocities, we determine orbital periods of 0.151424(3) days (3.63 hr) for V704 And and 0.130400(1) days (3.13 hr) for RX J2338+431. In V704 And, we find that the H{alpha} emission-line measures cluster into distinct regions on a plot of equivalent width versus full width at half-maximum, which evidently correspond to high, intermediate, and low photometric states. This allows us to assign spectra to photometric states when contemporaneous photometry is not available, an apparently novel method that may be useful in studies of other novalikes. Our low-state spectra of RX J2338+431 show features of an M-type secondary star, from which we estimate a distance of 890+/-200 pc, in good agreement with the Gaia DR2 (Cat. I/345) parallax.
5445. Radial velocities & photometry of AD Leonis & GJ 674
ID:
ivo://CDS.VizieR/J/AJ/155/192
Title:
Radial velocities & photometry of AD Leonis & GJ 674
Short Name:
J/AJ/155/192
Date:
21 Oct 2021
Publisher:
CDS
Description:
AD Leonis is a nearby magnetically active M dwarf. We find Doppler variability with a period of 2.23 days, as well as photometric signals: (1) a short-period signal, which is similar to the radial velocity signal, albeit with considerable variability; and (2) a long-term activity cycle of 4070+/-120 days. We examine the short-term photometric signal in the available All-Sky Automated Survey and Microvariability and Oscillations of STars (MOST) photometry and find that the signal is not consistently present and varies considerably as a function of time. This signal undergoes a phase change of roughly 0.8 rad when considering the first and second halves of the MOST data set, which are separated in median time by 3.38 days. In contrast, the Doppler signal is stable in the combined High-Accuracy Radial velocity Planet Searcher and High Resolution Echelle Spectrometer radial velocities for over 4700 days and does not appear to vary in time in amplitude, phase, period, or as a function of extracted wavelength. We consider a variety of starspot scenarios and find it challenging to simultaneously explain the rapidly varying photometric signal and the stable radial velocity signal as being caused by starspots corotating on the stellar surface. This suggests that the origin of the Doppler periodicity might be the gravitational tug of a planet orbiting the star in spin-orbit resonance. For such a scenario and no spin-orbit misalignment, the measured vsini indicates an inclination angle of 15.5+/-2.5{deg} and a planetary companion mass of 0.237+/-0.047 M_Jup_.
5446. Radial velocities & photometry of classical Cepheids
ID:
ivo://CDS.VizieR/J/A+A/318/416
Title:
Radial velocities & photometry of classical Cepheids
Short Name:
J/A+A/318/416
Date:
21 Oct 2021
Publisher:
CDS
Description:
Radial velocities and distances have been measured for a sample of 48 remote classical Cepheids located in the outer disc of the Galaxy (118deg<l<274deg). The distances are determined from BVI photometry, with semi-empirical metallicity corrections calibrated on the Magellanic Clouds. Using these Cepheids as tracers, the rotation curve of the disc is determined between R_0_ and 2R_0_. The result is a flat rotation curve about 30km/s lower than theta_0_, V_rot_=193+/-4km/s for R_0_==8.5kpc and theta_0_=220kms/s assumed, or V_rot_=167+/-4km/s for R_0_=8kpc and theta_0_=200km/s. The possible presence of non-axisymmetric components in the rotation of the outer disc is considered. We find a very small or vanishing value for any radial motion of the LSR or expansion/contraction motion.
5447. Radial velocities & photometry of the K dwarf HD26965
ID:
ivo://CDS.VizieR/J/AJ/155/126
Title:
Radial velocities & photometry of the K dwarf HD26965
Short Name:
J/AJ/155/126
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD 26965, with an orbital period of 42.364+/-0.015 days, or alternatively, as the presence of residual, uncorrected rotational activity in the data. Observations include data from HIRES, PFS, CHIRON, and HARPS, where 1111 measurements were made over 16 years. Our best solution for HD 26965 b is consistent with a super-Earth that has a minimum mass of 6.92+/-0.79 M_{Earth}_ orbiting at a distance of 0.215+/-0.008 au from its host star. We have analyzed the correlation between spectral activity indicators and the radial velocities from each instrument, showing moderate correlations that we include in our model. From this analysis, we recover a ~38-day signal, which matches some literature values of the stellar rotation period. However, from independent Mt. Wilson HK data for this star, we find evidence for a significant 42-day signal after subtraction of longer period magnetic cycles, casting doubt on the planetary hypothesis for this period. Although our statistical model strongly suggests that the 42-day signal is Doppler in origin, we conclude that the residual effects of stellar rotation are difficult to fully model and remove from this data set, highlighting the difficulties to disentangle small planetary signals and photospheric noise, particularly when the orbital periods are close to the rotation period of the star. This study serves as an excellent test case for future works that aim to detect small planets orbiting "Sun-like" stars using radial velocity measurements.
5448. Radial velocity and g-i color in M85 globular clusters
ID:
ivo://CDS.VizieR/J/ApJ/903/110
Title:
Radial velocity and g-i color in M85 globular clusters
Short Name:
J/ApJ/903/110
Date:
15 Mar 2022
Publisher:
CDS
Description:
We present a study on the stellar population and kinematics of globular clusters (GCs) in the peculiar galaxy M85. We obtain optical spectra of 89 GCs at 8kpc<R<160kpc using the MMT/Hectospec. We divide them into three groups, blue/green/red GCs (B/G/RGCs), with their (g-i)0 colors. All GC subpopulations have mean ages of about 10Gyr, but showing differences in metallicities. The BGCs and RGCs are the most metal-poor ([Z/H]~-1.49) and metal-rich ([Z/H]~-0.45), respectively, and the GGCs are in between. We find that the inner GC system exhibits a strong overall rotation that is entirely due to a disklike rotation of the RGC system. The BGC system shows little rotation. The GGCs show kinematic properties clearly distinct among the GC subpopulations, having higher mean velocities than the BGCs and RGCs and being aligned along the major axis of M85. This implies that the GGCs have an origin different from the other GC subpopulations. The rotation-corrected velocity dispersion of the RGC system is much lower than that of the BGC system, indicating the truncation of the red halo of M85. The BGCs have a flat velocity dispersion profile out to R=67kpc, reflecting the dark matter extent of M85. Using the velocity dispersion of the BGC system, we estimate the dynamical mass of M85 to be 3.8x1012M{sun}. We infer that M85 has undergone merging events lately, resulting in the peculiar kinematics of the GC system.
5449. Radial velocity and light curves of WASP-190
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.
5450. Radial velocity and photometry in NGC 4372
ID:
ivo://CDS.VizieR/J/A+A/567/A69
Title:
Radial velocity and photometry in NGC 4372
Short Name:
J/A+A/567/A69
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first in-depth study of the kinematic properties and derive the structural parameters of NGC 4372 based on the fit of a Plummer profile and a rotating, physical model. We explore the link between internal rotation to different cluster properties and together with similar studies of more GCs, we put these in the context of globular cluster formation and evolution. We present radial velocities for 131 cluster member stars measured from high-resolution FLAMES/GIRAFFE observations. Their membership to the GC is additionally confirmed from precise metallicity estimates. Using this kinematic data set we build a velocity dispersion profile and a systemic rotation curve. Additionally, we obtain an elliptical number density profile of NGC 4372 based on optical images using a MCMC fitting algorithm. From this we derive the cluster's half-light radius and ellipticity as r_h_=3.4'+/-0.04' and e=0.08+/-0.01. Finally, we give a physical interpretation of the observed morphological and kinematic properties of this GC by fitting an axisymmetric, differentially rotating, dynamical model. Our results show that NGC 4372 has an unusually high ratio of rotation amplitude to velocity dispersion (1.2 vs. 4.5km/s) for its metallicity. This, however, puts it in line with two other exceptional, very metal-poor GCs - M 15 and NGC 4590. We also find a mild flattening of NGC 4372 in the direction of its rotation. Given its old age, this suggests that the flattening is indeed caused by the systemic rotation rather than tidal interactions with the Galaxy. Additionally, we estimate the dynamical mass of the GC M_dyn=2.0+/-0.5 x 10^5 M_Sun based on the dynamical model, which constrains the mass-to-light ratio of NGC 4372 between 1.4 and 2.3 M_Sun/L_Sun, representative of an old, purely stellar population.