- ID:
- ivo://CDS.VizieR/J/AZh/84/147
- Title:
- Light curves of V838 Mon and V4332 Sgr
- Short Name:
- J/AZh/84/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze spectra of V838 Mon and V4332 Sgr taken in 2004-2005 using the 6m telescope of the Special Astrophysical Observatory with the UAGS and SCORPIO spectrographs. We conclude based on spectroscopy combined with archive photographs and modern CCD photometry that both peculiar red novae were binaries prior to their outbursts, and contained blue hot components that exploded. The secondary of V838 Mon is a hot B3V star, and that of V4332 Sgr is a cool M7 star.
Number of results to display per page
Search Results
1922. Light curves of WASP-74
- ID:
- ivo://CDS.VizieR/J/MNRAS/485/5168
- Title:
- Light curves of WASP-74
- Short Name:
- J/MNRAS/485/5168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broad-band photometry of 11 planetary transits of the hot Jupiter WASP-74 b, using three medium-class telescopes and employing the telescope-defocusing technique. Most of the transits were monitored through I filters and one was simultaneously observed in five optical (U, g', r', i', z') and three near-infrared (J, H, K) passbands, for a total of 18 light curves. We also obtained new high-resolution spectra of the host star. We used these new data to review the orbital and physical properties of the WASP-74 planetary system. We were able to better constrain the main system characteristics, measuring smaller radius and mass for both the hot Jupiter and its host star than previously reported in the literature. Joining our optical data with those taken with the HST in the near infrared, we built up an observational transmission spectrum of the planet, which suggests the presence of strong optical absorbers, as TiO and VO gases, in its atmosphere.
- ID:
- ivo://CDS.VizieR/J/ApJ/708/717
- Title:
- Light curve templates of RR Lyrae stars
- Short Name:
- J/ApJ/708/717
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an improved analysis of halo substructure traced by RR Lyrae stars in the Sloan Digital Sky Survey (SDSS) stripe 82 region. With the addition of SDSS-II data, a revised selection method based on new ugriz light curve templates results in a sample of 483 RR Lyrae stars that is essentially free of contamination. The main result from our first study persists: the spatial distribution of halo stars at galactocentric distances 5-100kpc is highly inhomogeneous. At least 20% of halo stars within 30kpc from the Galactic center can be statistically associated with substructure. We present strong direct evidence, based on both RR Lyrae stars and main-sequence stars, that the halo stellar number density profile significantly steepens beyond a Galactocentric distance of ~30kpc, and a larger fraction of the stars are associated with substructure. By using a novel method that simultaneously combines data for RR Lyrae and main-sequence stars, and using photometric metallicity estimates for main-sequence stars derived from deep co-added u-band data, we measure the metallicity of the Sagittarius dSph tidal stream (trailing arm) toward RA~2h-3h and DE~0{deg} to be 0.3dex higher ([Fe/H]=-1.2) than that of surrounding halo field stars.
- ID:
- ivo://CDS.VizieR/J/A+A/574/A60
- Title:
- Light curve templates of SNe Ib/c from SDSS
- Short Name:
- J/A+A/574/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical (ugriz) light curve templates of supernovae Ib/c from the SDSS II SN survey.
- ID:
- ivo://CDS.VizieR/J/AJ/156/6
- Title:
- Light element abundances of RGB & AGB stars in M10
- Short Name:
- J/AJ/156/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CN and CH band measurements for 137 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the Galactic globular cluster M10. Our measurements come from low-resolution spectroscopy taken with the Hydra spectrograph on the WIYN-3.5 m telescope. We use these measurements to identify two populations of stars within the cluster, CN-normal and CN-enhanced, and find that in our sample 60% of stars are CN-enhanced. Our large sample allows us to conduct a detailed analysis on the carbon and nitrogen abundances and the radial distribution of each population separately. Our analysis of the radial dependence shows that each population has the same radial distribution in the cluster, which is likely due to the cluster being dynamically evolved. We also compare our results to other methods of classifying multiple populations in globular clusters such as the Na-O anti-correlation and the HST pseudo-color-magnitude diagrams. We find that these three methods of identifying multiple populations are in good agreement with each other for M10 and all lead to an estimate of the fraction of second-generation stars approximately equal to 60%. Among AGB stars, when classified by the CN band, there appears to be a lack of second-generation stars when compared to the RGB stars. However, when classified by [N/Fe], we find a similar 60% of AGB stars in the second generation. Finally, we use the measured carbon and nitrogen abundances in RGB stars to study the change of each element with magnitude as stars evolve up the RGB, comparing the results to globular clusters of similar metallicity, M3 and M13.
- ID:
- ivo://CDS.VizieR/V/141
- Title:
- Light-Motion Curve Catalogue (LMCC) in Stripe 82
- Short Name:
- V/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a public archive of light-motion curves in Sloan Digital Sky Survey (SDSS) Stripe 82, covering 99{deg} in right ascension (20.7h to 3.3h) and spanning 2.52{deg} in declination (-1.26 to 1.26), for a total sky area of about 249sq.deg. Stripe 82 has been repeatedly monitored in the u, g, r, i and z bands over a seven-year baseline. Objects are cross-matched between runs, taking into account the effects of any proper motion. The resulting catalogue contains almost 4million light-motion curves of stellar objects and galaxies. The photometry are recalibrated to correct for varying photometric zeropoints, achieving ~20mmag and 30mmag root-mean-square (RMS) accuracy down to 18mag in the g, r, i and z bands for point sources and extended sources, respectively. The astrometry are recalibrated to correct for inherent systematic errors in the SDSS astrometric solutions, achieving 32mas and 35mas RMS accuracy down to 18mag for point sources and extended sources, respectively. For each light-motion curve, 229 photometric and astrometric quantities are derived and stored in a higher-level catalogue. On the photometric side, these include mean exponential and PSF magnitudes along with uncertainties, RMS scatter, {chi}^2^ per degree of freedom, various magnitude distribution percentiles, object type (stellar or galaxy), and eclipse, Stetson and Vidrih variability indices. On the astrometric side, these quantities include mean positions, proper motions as well as their uncertainties and {chi}^2^ per degree of freedom. The here presented light-motion curve catalogue is complete down to r~21.5mag and is at present the deepest large-area photometric and astrometric variability catalogue available.
- ID:
- ivo://CDS.VizieR/J/A+A/299/557
- Title:
- Light variations on Beta Pic
- Short Name:
- J/A+A/299/557
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed {beta} Pictoris photometric measurements obtained from La Silla by the Geneva Observatory from 1975 to 1992. These data show evidence of variations in the brightness of the star, with no color dependency. Here, we demonstrate that the light variations are present on long as well as on short time scales. On a long time scale, we show that the apparent magnitude of {beta} Pictoris decreased by 0.011+/-0.004mag from 1979 to 1982. Moreover, when we consider all the measurements, the chance that there is no variation at all can be estimated to be less than 10^-4^. On short time scales there is a peculiar feature observed during about 30 days; the variations may be as high as 0.04mag magnitude. A maximum entropy reconstruction of the photometric data is tentatively proposed and some physical interpretations are presented.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/125
- Title:
- Likelihood method for QSOs selection
- Short Name:
- J/ApJ/743/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new method for quasar target selection using photometric fluxes and a Bayesian probabilistic approach. For our purposes, we target quasars using Sloan Digital Sky Survey (SDSS) photometry to a magnitude limit of g=22. The efficiency and completeness of this technique are measured using the Baryon Oscillation Spectroscopic Survey (BOSS) data taken in 2010. This technique was used for the uniformly selected (CORE) sample of targets in BOSS year-one spectroscopy to be realized in the ninth SDSS data release. When targeting at a density of 40 objects deg^-2^ (the BOSS quasar targeting density), the efficiency of this technique in recovering z>2.2 quasars is 40%. The completeness compared to all quasars identified in BOSS data is 65%. This paper also describes possible extensions and improvements for this technique.
1929. Liller 1
- ID:
- ivo://CDS.VizieR/J/A+A/306/134
- Title:
- Liller 1
- Short Name:
- J/A+A/306/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out VRI and Gunn z observations of the obscured globular cluster Liller 1. The cluster is so reddened (A_V_=~9.0) that it is at the detection limit in V. The RGB in I vs. (I-z) shows a strong curvature. Recalling that the nearly solar metallicity globular clusters NGC 6553 and NGC 6528 present similar blanketing effects only in the visible bandpasses, we conclude that Liller 1 is considerably more metal-rich than these clusters. The CMD comparison of Liller 1 with the inner bulge field around it (located =~5deg from the nucleus), suggests that the cluster is as metallic as the most metallic fraction of this inner bulge population. Similarly deep I and z observations at =~0.5deg away from Liller 1, at the nominal position of Grindlay 1 do not reveal any cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/529/A75
- Title:
- Limb-darkening coefficients
- Short Name:
- J/A+A/529/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The degree of complexity of physics due to proximity effects in close binary stars is one of the most important challenges in theoretical stellar physics. The knowledge of how the specific intensity is distributed over the stellar disk is primordial to model the light curves of eclipsing binaries and planetary transits correctly. In order to provide theoretical input for light curve modelling codes, we present new calculations of gravity- and limb darkening coefficients for a wide range of effective temperatures, gravities, metallicities and microturbulent velocities. We have computed limb darkening coefficients for several atmosphere models, covering the transmission curves of the Kepler, CoRoT and Spitzer space missions as well as more widely used passbands (Stroemgren, Johnson-Cousins, Sloan). In addition to these computations, which were computed by adopting the Least-Square Method, we also performed calculations for the bi-parametric approximations by adopting the Flux Conservation Method to provide users with an additional tool to estimate the theoretical error bars. To facilitate the modelling of the effects of tidal and rotational distortions, we computed the GDCs y({lambda}) using the same models of stellar atmospheres as in the case of limb-darkening. Compared to previous work, a more general differential equation was used which now takes into account local gravity variations and the effects of convection. The limb darkening coefficients were computed with a larger numerical resolution (100um points instead of 15 or 17 as is often used in the ATLAS models) and five equations were used to describe the specific intensities (linear, quadratic, root-square, logarithmic and a 4-coefficient law (Equation 5)). Concerning the GDCs, the influence of the local gravity on y({lambda}) is shown as well as the effects of convection, which turn out to be very significant for cool stars. The results are tabulated for log(g)'s ranging from 0.0 to 5.0,-5.0<=log[M/H]<=+1, 2000K<=Teff<=50000K and for 5 values of the microturbulent velocity (0, 2, 4, 6, 8). ATLAS and PHOENIX plane-parallel atmosphere models were used for all the computations.
