- ID:
- ivo://CDS.VizieR/J/AJ/155/256
- Title:
- Spectroscopic validation of RAVE metal-poor stars
- Short Name:
- J/AJ/155/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a medium-resolution (R~2000) spectroscopic follow-up campaign of 1694 bright (V<13.5), very metal-poor star candidates from the RAdial Velocity Experiment (RAVE). Initial selection of the low-metallicity targets was based on the stellar parameters published in RAVE Data Releases 4 (Cat. III/272) and 5 (Cat. III/279). Follow up was accomplished with the Gemini-N and Gemini-S, the ESO/NTT, the KPNO/Mayall, and the SOAR telescopes. The wavelength coverage for most of the observed spectra allows for the determination of carbon and {alpha}-element abundances, which are crucial for considering the nature and frequency of the carbon-enhanced metal-poor (CEMP) stars in this sample. We find that 88% of the observed stars have [Fe/H]=< -1.0, 61% have [Fe/H]=< -2.0, and 3% have [Fe/H]=< -3.0 (with four stars at [Fe/H]=< -3.5). There are 306 CEMP star candidates in this sample, and we identify 169 CEMP Group I, 131 CEMP Group II, and 6 CEMP Group III stars from the A(C) versus [Fe/H] diagram. Inspection of the [{alpha}/C] abundance ratios reveals that five of the CEMP Group II stars can be classified as "mono-enriched second-generation" stars. Gaia DR1 matches were found for 734 stars, and we show that transverse velocities can be used as a confirmatory selection criteria for low-metallicity candidates. Selected stars from our validated list are being followed-up with high-resolution spectroscopy to reveal their full chemical-abundance patterns for further studies.
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- ID:
- ivo://CDS.VizieR/J/AJ/148/29
- Title:
- Spectroscopy and differential photometry of HATS-4
- Short Name:
- J/AJ/148/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery by the HATSouth survey of HATS-4b, an extrasolar planet transiting a V=13.46mag G star. HATS-4b has a period of P{approx}2.5167days, mass of M_p_{approx}1.32M_Jup_, radius of R_p_{approx}1.02R_Jup_, and density of {rho}_p_=1.55+/-0.16g/cm3{approx}1.24{rho}_Jup_. The host star has a mass of 1.00 M_{sun}_, a radius of 0.92 R_{sun}_, and a very high metallicity [Fe/H]=0.43+/-0.08. HATS-4b is among the densest known planets with masses between 1 and 2M_J_ and is thus likely to have a significant content of heavy elements of the order of 75M_{oplus}_. In this paper we present the data reduction, radial velocity measurements, and stellar classification techniques adopted by the HATSouth survey for the CORALIE spectrograph. We also detail a technique for simultaneously estimating vsini and macroturbulence using high resolution spectra.
- ID:
- ivo://CDS.VizieR/J/AJ/150/108
- Title:
- Spectroscopy and HST imaging in ONC
- Short Name:
- J/AJ/150/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent Hubble Space Telescope images have allowed the determination with unprecedented accuracy of motions and changes of shocks within the inner Orion Nebula. These originate from collimated outflows from very young stars, some within the ionized portion of the nebula and others within the host molecular cloud. We have doubled the number of Herbig-Haro objects known within the inner Orion Nebula. We find that the best-known Herbig-Haro shocks originate from relatively few stars, with the optically visible X-ray source COUP 666 driving many of them. While some isolated shocks are driven by single collimated outflows, many groups of shocks are the result of a single stellar source having jets oriented in multiple directions at similar times. This explains the feature that shocks aligned in opposite directions in the plane of the sky are usually blueshifted because the redshifted outflows pass into the optically thick photon-dominated region behind the nebula. There are two regions from which optical outflows originate for which there are no candidate sources in the SIMBAD database.
- ID:
- ivo://CDS.VizieR/J/AJ/150/168
- Title:
- Spectroscopy and photometry for HAT-P-50--HAT-P-53
- Short Name:
- J/AJ/150/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery and characterization of four transiting exoplanets by the HATNet survey. The planet HAT-P-50b has a mass of 1.35M_J_ and radius of 1.29R_J_, and orbits a bright (V=11.8mag) M=1.27M_{sun}_, R=1.70R_{sun}_ star every P=3.1220days. The planet HAT-P-51b has a mass of 0.31M_J_ and radius of 1.29R_J_, and orbits a V=13.4mag, M=0.98M_{sun}_, R=1.04R_{sun}_ star with a period of P=4.2180days. The planet HAT-P-52b has a mass of 0.82M_J_ and radius of 1.01R_J_, and orbits a V=14.1mag, M=0.89M_{sun}_, R=0.89R_{sun}_ star with a period of P=2.7536days. The planet HAT-P-53b has a mass of 1.48M_J_ and radius of 1.32R_J_, and orbits a V=13.7mag, M=1.09M_{sun}_, R=1.21R_{sun}_ star with a period of P=1.9616days. All four planets are consistent with having circular orbits and have masses and radii measured to better than 10% precision. The low stellar jitter and favorable R_p_/R_{star}_ ratio for HAT-P-51 make it a promising target for measuring the Rossiter-McLaughlin effect for a Saturn-mass planet.
- ID:
- ivo://CDS.VizieR/J/AJ/147/148
- Title:
- Spectroscopy and photometry of AP And
- Short Name:
- J/AJ/147/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- AP And is a well-detached F5 eclipsing binary star for which only a very limited amount of information was available before this publication. We have obtained very extensive measurements of the light curve (19097 differential V magnitude observations) and a radial velocity curve (83 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.277+/-0.004 and 1.251+/-0.004M_{sun}_, radii of 1.233+/-0.006 and 1.1953+/-0.005R_{sun}_, and temperatures of 6565+/-150K and 6495+/-150K. The distance to the system is about 400+/-30pc. Comparison with the theoretical properties of the stellar evolutionary models of the Yonsei-Yale series of Yi et al. shows good agreement between the observations and the theory at an age of about 500 Myr and a slightly sub-solar metallicity.
- ID:
- ivo://CDS.VizieR/J/AJ/144/81
- Title:
- Spectroscopy and photometry of CV candidates
- Short Name:
- J/AJ/144/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Catalina Real Time Survey (CRTS) has found over 500 cataclysmic variable (CV) candidates, most of which were previously unknown. We report here on follow-up spectroscopy of 36 of the brighter objects. Nearly all of the spectra are typical of CVs at minimum light. One object appears to be a flare star, while another has a spectrum consistent with a CV but lies, intriguingly, at the center of a small nebulosity. We measured orbital periods for eight of the CVs, and estimated distances for two based on the spectra of their secondary stars. In addition to the spectra, we obtained direct imaging for an overlapping sample of 37 objects, for which we give magnitudes and colors. Most of our new orbital periods are shortward of the so-called period gap from roughly 2 to 3hr. By considering the cross-identifications between the Catalina objects and other catalogs such as the Sloan Digital Sky Survey, we argue that a large number of CVs remain uncataloged. By comparing the CRTS sample to lists of previously known CVs that CRTS does not recover, we find that the CRTS is biased toward large outburst amplitudes (and hence shorter orbital periods). We speculate that this is a consequence of the survey cadence.
- ID:
- ivo://CDS.VizieR/J/AJ/151/89
- Title:
- Spectroscopy and photometry of HATS-17
- Short Name:
- J/AJ/151/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HATS-17b, the first transiting warm Jupiter of the HATSouth network. HATS-17b transits its bright (V=12.4) G-type (M_{star}_=1.131+/-0.030M_{sun}_, R_{star}_=1.090_-0.046_^+0.070^) metal-rich ([Fe/H]=+0.3dex) host star in a circular orbit with a period of P=16.2546days. HATS-17b has a very compact radius of 0.777+/-0.056R_J_ given its Jupiter-like mass of 1.338+/-0.065M_J_. Up to 50% of the mass of HATS-17b may be composed of heavy elements in order to explain its high density with current models of planetary structure. HATS-17b is the longest period transiting planet discovered to date by a ground-based photometric survey, and is one of the brightest transiting warm Jupiter systems known. The brightness of HATS-17 will allow detailed follow-up observations to characterize the orbital geometry of the system and the atmosphere of the planet.
- ID:
- ivo://CDS.VizieR/J/AJ/152/88
- Title:
- Spectroscopy and photometry of HATS-11 and HATS-12
- Short Name:
- J/AJ/152/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two transiting extrasolar planets from the HATSouth survey. HATS-11, a V=14.1 G0-star shows a periodic 12.9mmag dip in its light curve every 3.6192days and a radial velocity variation consistent with a Keplerian orbit. HATS-11 has a mass of 1.000+/-0.060M_{Sun}_, a radius of 1.444+/-0.057R_{Sun}_ and an effective temperature of 6060+/-150K, while its companion is a 0.85+/-0.12M_J_, 1.510+/-0.078R_J_ planet in a circular orbit. HATS-12 shows a periodic 5.1mmag flux decrease every 3.1428days and Keplerian radial velocities variations around a V=12.8 F-star. HATS-12 has a mass of 1.489+/-0.071M_{Sun}_, a radius of 2.21+/-0.21R_{Sun}_, and an effective temperature of 6408+/-75K. For HATS-12b, our measurements indicate that this is a 2.38+/-0.11M_J_, 1.35+/-0.17R_J_ planet in a circular orbit. Both host stars show subsolar metallicities of -0.390+/-0.060dex and -0.100+/-0.040dex, respectively, and are (slightly) evolved stars. In fact, HATS-11 is among the most metal-poor and, HATS-12, with a logg_*_ of 3.923+/-0.065, is among the most evolved stars hosting a hot-Jupiter planet. Importantly, HATS-11 and HATS-12 have been observed in long cadence by Kepler as part of K2 campaign 7 (EPIC216414930 and EPIC218131080 respectively).
- ID:
- ivo://CDS.VizieR/J/AJ/147/1
- Title:
- Spectroscopy and photometry of HP Aur
- Short Name:
- J/AJ/147/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometric, spectroscopic, and eclipse timing observations of the eclipsing binary star HP Aur allow for very accurate orbital determinations, even in the presence of a third body and transient starspot activity. The eclipsing binary masses are determined to an accuracy of +/-0.4% and the radii to +/-0.6%. The masses are 0.9543+/-0.0041 and 0.8094+/-0.0036 solar masses, and the radii are 1.0278+/-0.0042 and 0.7758+/-0.0034 solar radii, respectively. The orbital period in the outer orbit is accurately determined for the first time: 4.332+/-0.011yr. A comparison with current theories of stellar evolution shows that the components' absolute properties can be well-matched by the current models at an age of about 7 billion years.
- ID:
- ivo://CDS.VizieR/J/AJ/149/34
- Title:
- Spectroscopy and photometry of IM Per
- Short Name:
- J/AJ/149/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IM Per is a detached A7 eccentric eclipsing binary star. We have obtained extensive measurements of the light curve (28225 differential magnitude observations) and radial velocity curve (81 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.7831+/-0.0094 and 1.7741+/-0.0097 solar masses, and radii of 2.409+/-0.018 and 2.366+/-0.017 solar radii. The orbital period is 2.25422694(15) days and the eccentricity is 0.0473(26). A faint third component was detected in the analysis of the light curves, and also directly observed in the spectra. The observed rate of apsidal motion is consistent with theory (U=151.4+/-8.4year). We determine a distance to the system of 566+/-46pc.
