- ID:
- ivo://CDS.VizieR/J/A+A/588/L6
- Title:
- WASP-12 transit light curves
- Short Name:
- J/A+A/588/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most hot Jupiters are expected to spiral in toward their host stars because the angular momentum of the orbital motion is transferred to the stellar spin. Their orbits can also precess as a result of planet-star interactions. Calculations show that both effects might be detected for the very-hot exoplanet WASP-12 b using the method of precise transit-timing over a time span of about 10yr. We acquired new precise light curves for 29 transits of WASP-12 b, spanning four observing seasons from November 2012 to February 2016. New mid-transit times, together with those from the literature, were used to refine the transit ephemeris and analyze the timing residuals. We find that the transit times of WASP-12 b do not follow a linear ephemeris with a 5-{sigma} confidence level. They may be approximated with a quadratic ephemeris that gives a change rate in the orbital period of (-2.56+/-0.40)x10^-2^s/yr. The tidal quality parameter of the host star was found to be equal to 2.5x10^5^, which is similar to theoretical predictions for Sun-like stars. We also considered a model in which the observed timing residuals are interpreted as a result of the apsidal precession. We find, however, that this model is statistically less probable than the orbital decay.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/132/1669
- Title:
- Wide-field CCD phot. around nine open clusters
- Short Name:
- J/AJ/132/1669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we study the evolution of the core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained with the 105cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters vary from 16 to 2000Myr and 9 to 10.8kpc, respectively. Barring Be 62, which is a young open cluster, other clusters show a uniform reddening across the cluster region.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A54
- Title:
- WINGS cluster survey second u-band extension
- Short Name:
- J/A+A/637/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second u-band extension of the WIde-field Nearby Galaxy-cluster Survey (WINGS), obtained by imaging 39 clusters with the ESO-VLT survey telescope. It follows the first one, realized with several telescopes of the northern hemisphere in the U Cousin-Bessel filter band (Omizzolo et al., 2014A&A...561A.111O, Cat. J/A+A/561/A111), that covered 17 clusters. The u-band data, in combination with those already achieved by the WINGS survey, will permit a detailed multi-wavelength investigation of the properties of the member galaxies from the cluster center out to the periphery. We have derived with SEXT the main properties of the galaxies in the observed fields and measured the u-V colors on circular apertures of increasing radius. The photometric accuracy of the magnitudes has been calibrated with the standard stars and tested by means of comparisons with the u-band data of the Sloan Digital Sky Survey (SDSS). We present the catalogs of the photometric analysis performed by SEXT. Then we provide a brief analysis of the u-V vs V color-magnitude diagram of our clusters, the plots of the color as a function of the cluster-centric distance (for cluster members only) and the correlation of the current star formation rate (SFR) vs the absolute V and u magnitudes for the galaxies in the observed fields.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A87
- Title:
- WINGS galaxies surface photometry with GASPHOT
- Short Name:
- J/A+A/572/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the B, V, and K band surface photometry catalogs obtained by running the automatic software GASPHOT on galaxies from the WINGS cluster survey with isophotal areas larger than 200 pixels. The luminosity growth curves of stars and galaxies in a given catalog relative to a given cluster image were obtained simultaneously by slicing the image with a fixed surface brightness step in several SExtractor runs. Then, using a single Sersic law convolved with a space-varying point spread function (PSF), GASPHOT performed a simultaneous {chi}^2^ best-fit of the major- and minor-axis luminosity growth curves of galaxies. We outline the GASPHOT performances and compare our surface photometry with that obtained by SExtractor, GALFIT, and GIM2D. This analysis is aimed at providing statistical information about the accuracy that is generally achieved by the softwares for automatic surface photometry of galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/501/851
- Title:
- WINGS JK photometry of 28 galaxy clusters
- Short Name:
- J/A+A/501/851
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third paper in a series devoted to the WIde-field Nearby Galaxy-cluster Survey (WINGS). WINGS is a long-term project aimed at gathering wide-field, multiband imaging and spectroscopy of galaxies in a complete sample of 77 X-ray selected, nearby clusters (0.04<z<0.07) located far from the galactic plane (|b|>=20{deg}). The main goal of this project is to establish a local reference sample for evolutionary studies of galaxies and galaxy clusters. This paper presents the near-infrared (J,K) photometric catalogs of 28 clusters of the WINGS sample and describes the procedures followed to construct them.
- ID:
- ivo://CDS.VizieR/J/AJ/146/43
- Title:
- WIYN open cluster study. LV. NGC 6819
- Short Name:
- J/AJ/146/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present proper motions and astrometric membership analysis for 15750 stars around the intermediate-age open cluster NGC 6819. The accuracy of relative proper motions for well-measured stars ranges from ~0.2mas/yr within 10' of the cluster center to 1.1mas/yr outside this radius. In the proper motion vector-point diagram, the separation between the cluster members and field stars is convincing down to V~18 and within 10' from the cluster center. The formal sum of membership probabilities indicates a total of ~2500 cluster members down to V~22. We confirm the cluster membership of several variable stars, including some eclipsing binaries. The estimated absolute proper motion of NGC 6819 is {mu}_x_^abs^=-2.6+/-0.5 and {mu}_y_^abs^=-4.2+/-0.5mas/yr. A cross-identification between the proper motion catalog and a list of X-ray sources in the field of NGC 6819 resulted in a number of new likely optical counterparts, including a candidate CV. For the first time we show that there is significant differential reddening toward NGC 6819.
- ID:
- ivo://CDS.VizieR/J/AJ/143/10
- Title:
- 2008-2009 WIYN speckle observations of binaries. VII.
- Short Name:
- J/AJ/143/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Five hundred thirty-one speckle measures of binary stars are reported. These data were taken mainly during the period 2008 June through 2009 October at the WIYN 3.5m Telescope at Kitt Peak and represent the last data set of single-filter speckle observations taken in the WIYN speckle program prior to the use of the current two-channel speckle camera. The astrometric and photometric precision of these observations is consistent with previous papers in this series: we obtain a typical linear measurement uncertainty of approximately 2.5mas, and the magnitude differences reported have typical uncertainties in the range of 0.1-0.14mag. In combination with measures already in the literature, the data presented here permit the revision of the orbit of A 1634AB (= HIP 76041) and the first determination of visual orbital elements for HDS 1895 (= HIP 65982).
- ID:
- ivo://CDS.VizieR/J/A+A/561/A12
- Title:
- W3 Main JHKs photometry
- Short Name:
- J/A+A/561/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Embedded clusters like W3 Main are complex and dynamically evolving systems that represent an important phase in the star formation process. We aim to characterize of the entire stellar content of W3 Main in a statistical sense, which will then identify possible differences in evolutionary phase of the stellar populations and find clues about the formation mechanism of this massive embedded cluster. Deep JHKs imaging is used to derive the disk fraction, Ks-band luminosity functions, and mass functions for several subregions in W3 Main. A two-dimensional completeness analysis using artificial star experiments is applied as a crucial ingredient for assessing realistic completeness limits for our photometry. We find an overall disk fraction of 7.7+/-2.3%, radially varying from 9.4+/-3.0 in the central 1pc to 5.6+/-2.2% in the outer parts of W3 Main. The mass functions derived for three subregions are consistent with a Kroupa and Chabrier mass function. The mass function of IRSN3 is complete down to 0.14M_{sun}_ and shows a break at M~0.5M_{sun}_. We interpret the higher disk fraction in the center as evidence that the cluster center is younger. We find that the evolutionary sequence observed in the low-mass stellar population is consistent with the observed age spread among the massive stars. An analysis of the mass function variations does not show evidence of mass segregation. W3 Main is currently still actively forming stars, showing that the ionizing feedback of OB stars is confined to small areas (~0.5pc). The FUV feedback might be influencing large regions of the cluster as suggested by the low overall disk fraction.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A63
- Title:
- W51 OB stars NIR spectroscopy
- Short Name:
- J/A+A/624/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The interplay between the formation of stars, stellar feedback and cloud properties strongly influences the star formation history of giant molecular clouds. The formation of massive stars leads to a variety of stellar clusters, ranging from low stellar density OB associations to dense, gravitationally bound starburst clusters. We aimed at identifying the massive stellar content and reconstructing the star formation history of the W51 giant molecular cloud. We performed near-infrared imaging and K-band spectroscopy of the massive stars in W51. We analysed the stellar populations using colour-magnitude and colour-colour diagrams and compared the properties of the spectroscopically identified stars with stellar evolution models. We derive the ages of the different sub-clusters in W51 and, based on our spectroscopy derive an age for W51 of 3Myrs or less. The age of the P Cygni star LS1 and the presence of two still forming proto- clusters suggests that the star formation history of W51 is more complex than a single burst. We did not find evidence for triggered star formation and we concluded that the star formation in W51 is multi seeded. We finally concluded that W51 is a OB association where different sub-clusters form over a time span of at least 3-5Myrs.
- ID:
- ivo://CDS.VizieR/J/AJ/152/192
- Title:
- WOCS. LXXII. A uvbyCaHb study of NGC 2506
- Short Name:
- J/AJ/152/192
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precision uvbyCaH{beta} photometry of the metal-deficient, old open cluster NGC2506 is presented. The survey covers an area of 20'*20' and extends to V~18 for b-y and H{beta} and to V~17.0 for c_1_ and hk. For V brighter than 16.0, photometric scatter among the indices leads to the recovery of six known variables within the cluster core and five new variables in the outer 5' of the survey field. Proper motions, radial velocities, and precise multicolor indices are used to isolate a highly probable sample of cluster members from the very rich color-magnitude diagram. From 257 highly probable members at the cluster turnoff, we derive a reddening estimate of E(b-y)=0.042+/-0.001 (E(B-V)=0.058+/-0.001), where the errors refer to the internal standard errors of the mean. [Fe/H] is derived from the A/F dwarf members using both m_1_ and hk, leading to [Fe/H]=-0.296+/-0.011 (sem) and -0.317+/-0.004 (sem), respectively. The weighted average, heavily dominated by hk, is [Fe/H]=-0.316+/-0.033. Based on red giant members, we place an upper limit of +/-0.010 on the variation in the reddening across the face of the cluster. We also identify two dozen potential red giant cluster members outside the cluster core. Victoria-Regina isochrones on the Stromgren system produce an excellent match to the cluster for an apparent modulus of (m-M)=12.75+/-0.1 and an age of 1.85+/-0.05Gyr.
