- 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.
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1562. 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/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.
1566. 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.
- ID:
- ivo://CDS.VizieR/J/A+A/634/A93
- Title:
- Limb-darkening coefficients for compact stars
- Short Name:
- J/A+A/634/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The distribution of the specific intensity over the stellar disk is an essential tool for modeling the light curves in eclipsing binaries, planetary transits, and stellar diameters through interferometric techniques, line profiles in rotating stars, gravitational microlensing, etc. However, the available theoretical calculations are mostly restricted to stars on the main sequence or the giant branch, and very few calculations are available for compact stars. The main objective of the present work is to extend these investigations by computing the gravity and limb-darkening coefficients for white dwarf atmosphere models with hydrogen, helium, or mixed compositions (types DA, DB, and DBA). We computed gravity and limb-darkening coefficients for DA, DB, and DBA white dwarfs atmosphere models, covering the transmission curves of the Sloan, UBVRI, Kepler, TESS, and Gaia photometric systems. Specific calculations for the HiPERCAM instrument were also carried out. For all calculations of the limb-darkening coefficients we used the least-squares method. Concerning the effects of tidal and rotational distortions, we also computed for the first time the gravity-darkening coefficients $y(\lambda)$ for white dwarfs using the same models of stellar atmospheres as in the case of limb-darkening. A more general differential equation was introduced to derive these quantities, including the partial derivative <{\partial}lnI_o_(lambda)/{\partial}lng)_Teff_. Six laws were adopted to describe the specific intensity distribution: linear, quadratic, square root, logarithmic, power-2, and a more general one with four coefficients. The computations are presented for the chemical compositions log[H/He]=-10.0 (DB), -2.0 (DBA) and He/H=0 (DA), with logg varying between 5.0 and 9.5 and effective temperatures between 3750K-100000K. For effective temperatures higher than 40000K, the models were also computed adopting nonlocal thermal equilibrium (DA). The adopted mixing-length parameters are ML2/{alpha}= 0.8 (DA case) and 1.25 (DB and DBA). The results are presented in the form of 112 tables. Additional calculations, such as for other photometric systems and/or different values of log[H/He], logg, and Teff can be performed upon request.
- ID:
- ivo://CDS.VizieR/J/A+A/567/A3
- Title:
- Limb-darkening coefficients for MOST
- Short Name:
- J/A+A/567/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new calculations of limb and gravity-darkening coefficients to be used as input in many fields of stellar physics such as synthetic light curves of double-lined eclipsing binaries and planetary transits, studies of stellar diameters or line profiles in rotating stars. We compute the limb-darkening coefficients specifically for the photometric system of the satellite MOST (Microvariability and Oscillations in STars). All computations were performed by adopting the least-square method, but for completeness we also performed calculations for the linear and bi-parametric approaches by adopting the flux conservation method. The passband gravity-darkening coefficients y({lambda}) were computed by adopting a more general differential equation, which also takes the effects of convection into account. We used two stellar atmosphere models: ATLAS (plane-parallel) and PHOENIX (spherical and quasi-spherical). We adopted six laws to describe the specific intensity distribution: linear, quadratic, square root, logarithmic, exponential, and a more general one with four terms. The covered ranges of T_eff_, log g, metallicities, and microturbulent velocities are [1500-50000K, 0-5.5,-5.0-1.0, 0-8km/s], respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/554/A98
- Title:
- Limb-darkening coefficients for red giants
- Short Name:
- J/A+A/554/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Model stellar atmospheres are fundamental tools for understanding stellar observations from interferometry, microlensing, eclipsing binaries and planetary transits. However, the calculations also include assumptions, such as the geometry of the model. We use intensity profiles computed for both plane-parallel and spherically symmetric model atmospheres to determine fitting coefficients in the BVRIHK, CoRoT and Kepler wavebands for limb darkening using several different fitting laws, for gravity-darkening and for interferometric angular diameter corrections. Comparing predicted variables for each geometry, we find that the spherically symmetric model geometry leads to different predictions for surface gravities logg<3. In particular, the most commonly used limb-darkening laws produce poor fits to the intensity profiles of spherically symmetric model atmospheres, which indicates the need for more sophisticated laws. Angular diameter corrections for spherically symmetric models range from 0.67 to 1, compared to the much smaller range from 0.95 to 1 for plane-parallel models.
