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6151. Spectroscopy and HST photometry in Westerlund 2
ID:
ivo://CDS.VizieR/J/AJ/145/125
Title:
Spectroscopy and HST photometry in Westerlund 2
Short Name:
J/AJ/145/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a spectroscopic and photometric determination of the distance to the young Galactic open cluster Westerlund 2 using WFPC2 imaging from the Hubble Space Telescope (HST) and ground-based optical spectroscopy. HST imaging in the F336W, F439W, F555W, and F814W filters resolved many sources previously undetected in ground-based observations and yielded photometry for 1136 stars. We identified 15 new O-type stars, along with two probable binary systems, including MSP188 (O3+O5.5). We fit reddened spectral energy distributions based on the Padova isochrones to the photometric data to determine individual reddening parameters R_V_ and A_V_for O-type stars in Wd2. We find average values <R_V_>=3.77+/-0.09 and <A_V_>=6.51+/-0.38mag, which result in a smaller distance than most other spectroscopic and photometric studies. After a statistical distance correction accounting for close unresolved binaries (factor of 1.08), our spectroscopic and photometric data on 29 O-type stars yield that Westerlund 2 has a distance <d>=4.16+/-0.07(random)+0.26(systematic)kpc. The cluster's age remains poorly constrained, with an upper limit of 3Myr. Finally, we report evidence of a faint mid-IR polycyclic aromatic hydrocarbon ring surrounding the well-known binary candidate MSP 18, which appears to lie at the center of a secondary stellar grouping within Westerlund 2.
6152. Spectroscopy and photometry for HAT-P-50--HAT-P-53
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.
6153. Spectroscopy and photometry in A2744 and A2537
ID:
ivo://CDS.VizieR/J/A+A/500/947
Title:
Spectroscopy and photometry in A2744 and A2537
Short Name:
J/A+A/500/947
Date:
21 Oct 2021
Publisher:
CDS
Description:
The current paradigm of cosmic formation and evolution of galaxy clusters foresees growth mostly through merging. Galaxies in the infall region or in the core of a cluster undergo transformations owing to different environmental stresses. For two X-ray luminous clusters at redshift z~0.3 with opposite X-ray morphologies (i.e., dynamical states), RXCJ0014.3-3022 and RXCJ2308.3-0211, we assess differences in galaxy populations as a function of cluster topography. This is a pilot study for the joint X-ray and optical analysis of the REFLEX-DXL cluster sample.
6154. Spectroscopy and photometry of AP And
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.
6155. Spectroscopy and photometry of CV candidates
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.
6156. Spectroscopy and photometry of HATS-17
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.
6157. Spectroscopy and photometry of HATS-11 and HATS-12
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).
6158. Spectroscopy and photometry of HP Aur
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.
6159. Spectroscopy and photometry of IM Per
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.
6160. Spectroscopy and photometry of V501 Her
ID:
ivo://CDS.VizieR/J/AJ/148/71
Title:
Spectroscopy and photometry of V501 Her
Short Name:
J/AJ/148/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
V501 Her is a well detached G3 eclipsing binary star with a period of 8.597687days for which we have determined very accurate light and radial-velocity curves using robotic telescopes. Results of these data indicate that the component stars have masses of 1.269+/-0.004 and 1.211+/-0.003 solar masses, radii of 2.001+/-0.003 and 1.511+/-0.003 solar radii, and temperatures of 5683+/-100 K and 5720+/-100K, respectively. Comparison with the Yonsei-Yale series of evolutionary models results in good agreement at an age of about 5.1Gyr for a somewhat metal-rich composition. Those models indicate that the more massive, larger, slightly cooler star is just beyond core hydrogen exhaustion while the less massive, smaller, slightly hotter star has not quite reached core hydrogen exhaustion. The orbit is not yet circularized, and the components are rotating at or near their pseudosynchronous velocities. The distance to the system is 420+/-30pc.