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5561. Red variables near NGC 6749
ID:
ivo://CDS.VizieR/J/other/IBVS/5187
Title:
Red variables near NGC 6749
Short Name:
J/other/IBVS/518
Date:
21 Oct 2021
Publisher:
CDS
Description:
As part of a photometric study of the obscured globular cluster NGC 6749, Rosino et al. (1997, Cat. <J/MNRAS/289/745>) include a list of seventy-eight new red variables within 1{deg} of the cluster. Although two of the stars lie near the cluster, probably none of them is related to it. Perhaps because the stars' positions were given to only 0.1' precision, none of the stars has yet received a GCVS designation.
5562. Red variable stars in NSVS
ID:
ivo://CDS.VizieR/J/other/JAVSO/37.169
Title:
Red variable stars in NSVS
Short Name:
J/other/JAVSO/37
Date:
21 Oct 2021
Publisher:
CDS
Description:
Candidate variable stars in the publicly available data of the Northern Sky Variability Survey (NSVS) were identified by data mining the 2MASS survey for entries that matched the following criteria: DE>20.000,(J-K)>1.2, and Jmag<7.000. A total of 1233 such stars were identified: 1 type M, 64 type M:, 26 type SR:, and 1142 type L:, with amplitudes between 0.3 magnitude and 3.4 magnitudes. Only stars not listed in the International Variable Star Index (VSX) at the time of submission or not identified as variable in Simbad have been included.
5563. Reference A0V stars
ID:
ivo://CDS.VizieR/J/A+AS/137/273
Title:
Reference A0V stars
Short Name:
J/A+AS/137/273
Date:
21 Oct 2021
Publisher:
CDS
Description:
Hipparcos data for 71 nearby dwarf A0 stars were combined with other data, in particular with high resolution spectra to establish the HR diagram in this temperature range. Almost 30% of unknown binaries were detected and discarded before establishing the M-L relation for bright A0 V field stars. The relationship derived for these single stars is compared to the classical diagram derived from eclipsing binaries. The scatter of the latter is examined and the role of gravity is discussed. A good agreement is found between the evolution-based surface gravity logg_ev_ and the value of logg_ph_ obtained from photometric data.
5564. Refined Analysis of T-Cyg1-12664
ID:
ivo://CDS.VizieR/J/A+A/600/A55
Title:
Refined Analysis of T-Cyg1-12664
Short Name:
J/A+A/600/A55
Date:
21 Oct 2021
Publisher:
CDS
Description:
The observational mass-radius relation of main sequence stars with masses between ~0.3 and 1.0M_{sun}_ reveals deviations between the stellar radii predicted by models and the observed radii of stars in detached binaries. We generate an accurate physical model of the low-mass eclipsing binary T-Cyg1-12664 in the Kepler mission field to measure the physical parameters of its components and to compare them with the prediction of theoretical stellar evolution models. We analyze the Kepler mission light curve of T-Cyg1-12664 to accurately measure the times and phases of the primary and secondary eclipse. In addition, we measure the rotational period of the primary component by analyzing the out-of-eclipse oscillations that are due to spots. We accurately constrain the effective temperature of the system using ground-based absolute photometry in B, V, R_C_, and I_C_. We also obtain and analyze VR_C_I_C_ differential light curves to measure the eccentricity and the orbital inclination of the system, and a precise Teff ratio. From the joint analysis of new radial velocities and those in the literature we measure the individual masses of the stars. Finally, we use the PHOEBE code to generate a physical model of the system.
5565. Reflectivity of 4 Gallilean satellites with ISS
ID:
ivo://CDS.VizieR/J/AJ/160/238
Title:
Reflectivity of 4 Gallilean satellites with ISS
Short Name:
J/AJ/160/238
Date:
10 Dec 2021
Publisher:
CDS
Description:
For terrestrial exoplanets with thin or no atmospheres, the surface contributes light to the reflected light signal of the planet. Measurement of the variety of disk-integrated brightnesses of bodies in the solar system and the variation with illumination and wavelength is essential for both planning imaging observations of directly imaged exoplanets and interpreting the eventual data sets. Here we measure the change in brightness of the Galilean satellites as a function of planetocentric longitude, illumination phase angle, and wavelength. The data span a range of wavelengths from 400 to 950nm and predominantly phase angles from 0{deg} to 25{deg}, with some constraining observations near 60{deg}-140{deg}. Despite the similarity in size and density between the moons, surface inhomogeneities result in significant changes in the disk-integrated reflectivity with planetocentric longitude and phase angle. We find that these changes are sufficient to determine the rotational periods of the moon. We also find that at low phase angles, the surface can produce reflectivity variations of 8%-36%, and the limited high phase angle observations suggest variations will have proportionally larger amplitudes at higher phase angles. Additionally, all of the Galilean satellites are darker than predicted by an idealized Lambertian model at the phases most likely to be observed by direct imaging missions. If Earth-sized exoplanets have surfaces similar to that of the Galilean moons, we find that future direct imaging missions will need to achieve precisions of less than 0.1ppb. Should the necessary precision be achieved, future exoplanet observations could exploit similar observation schemes to deduce surface variations, determine rotation periods, and potentially infer surface composition.
5566. Region I of La Silla QUEST RR Lyrae star survey
ID:
ivo://CDS.VizieR/J/ApJ/781/22
Title:
Region I of La Silla QUEST RR Lyrae star survey
Short Name:
J/ApJ/781/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
A search for RR Lyrae stars (RRLSs) in ~840deg^2^ of the sky in right ascension 150{deg}-210{deg} and declination -10{deg} to + 10{deg} yielded 1013 type ab and 359 type c RRLS. This sample is used to study the density profile of the Galactic halo, halo substructures, and the Oosterhoff type of the halo over distances (d_{sun}_) from ~5 to ~80kpc. The halo is flattened toward the Galactic plane, and its density profile steepens in slope at galactocentric distances greater than ~25kpc. The RRLS in the stellar stream from the Sagittarius dwarf spheroidal (dSph) galaxy match well the model of Law & Majewski for the stars that were stripped 1.3-3.2Gyr ago, but not for the ones stripped 3.2-5.0Gyr ago. Over densities are found at the locations of the Virgo Overdensity and the Virgo Stellar Stream. Within 1{deg} of 1220-1, which Jerjen et al. identify as a halo substructure at d_{sun}_~24kpc, there are four RRLS that are possibly members. Away from substructures, the RRLS are a mixture of Oosterhoff types I and II, but mostly OoI (~73%). The accretion of galaxies resembling in RRLS content the most massive Milky Way satellites (LMC, SMC, For, Sgr) may explain this preponderance of OoI. Six new RRLS and three new anomalous Cepheids were found in the Sextans dSph galaxy.
5567. Region of the open cluster Tr 14
ID:
ivo://CDS.VizieR/J/A+AS/116/75
Title:
Region of the open cluster Tr 14
Short Name:
J/A+AS/116/75
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present UBVRI CCD imaging photometry down to approximately V=19mag in the area of the very young open cluster Tr 14. Our results confirm the existence of an anomalous extinction law in the area if it is interpreted in terms of the UBVRI photometry. According to our analysis the cluster distance is d=3100 (V_0_-M_V_=12.50mag) and its age is 1.5+/-.5x10^6^y. We want to draw the attention on stars which, from the observed magnitude-spread at constant color, could be stars in an early stage of evolution. In that case, the observed spread leads to assume that the process of star formation in Tr 14 is continuous whereas, from pre-main sequence evolutionary tracks, a duration of about 5x10^6^y is deduced for it. The computation of the cluster initial mass function reveals a flat slop e even though it still compares to a Salpeter law. At the same time, we found a spatial variation of the cluster IMF, which could be explained by mass segregation in the star formation process. The cluster youth and its compact appearance seem to confirm that it is far from virial equilibrium. The observed tot al cluster mass is around 2000M_{sun}_ and its core contains about 40% of the total.
5568. Relations between spectra and colors of SNe Ia
ID:
ivo://CDS.VizieR/J/ApJ/742/89
Title:
Relations between spectra and colors of SNe Ia
Short Name:
J/ApJ/742/89
Date:
21 Oct 2021
Publisher:
CDS
Description:
To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of 255 SNe, based primarily on data from the CfA Supernova Program, we examine how the velocity evolution and line strengths of SiII(6355) and CaII H&K are related to the B-V color at peak brightness. We find that the maximum-light velocity of SiII6355 and CaII H&K and the maximum-light pseudo-equivalent width of SiII6355 are correlated with intrinsic color, with intrinsic color having a linear relation with the SiII6355 measurements. CaII H&K does not have a linear relation with intrinsic color, but lower-velocity SNe tend to be intrinsically bluer. Combining the spectroscopic measurements does not improve intrinsic color inference. The intrinsic color scatter is larger for higher-velocity SNe Ia - even after removing a linear trend with velocity - indicating that lower-velocity SNe Ia are more "standard crayons". Employing information derived from SN Ia spectra has the potential to improve the measurements of extragalactic distances and the cosmological properties inferred from them.
5569. Relative Ic photometry of WASP-17
ID:
ivo://CDS.VizieR/J/ApJ/709/159
Title:
Relative Ic photometry of WASP-17
Short Name:
J/ApJ/709/159
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of the transiting giant planet WASP-17b, the least-dense planet currently known. It is 1.6 Saturn masses, but 1.5-2 Jupiter radii, giving a density of 6%-14% that of Jupiter. WASP-17b is in a 3.7 day orbit around a sub-solar metallicity, V=11.6, F6 star. Preliminary detection of the Rossiter-McLaughlin effect suggests that WASP-17b is in a retrograde orbit ({lambda}~-150{deg}), indicative of a violent history involving planet-planet or star-planet scattering. WASP-17b's bloated radius could be due to tidal heating resulting from recent or ongoing tidal circularization of an eccentric orbit, such as the highly eccentric orbits that typically result from scattering interactions. It will thus be important to determine more precisely the current orbital eccentricity by further high-precision radial velocity measurements or by timing the secondary eclipse, both to reduce the uncertainty on the planet's radius and to test tidal-heating models. Owing to its low surface gravity, WASP-17b's atmosphere has the largest scale height of any known planet, making it a good target for transmission spectroscopy.
5570. Relative photometry of WASP-10
ID:
ivo://CDS.VizieR/J/ApJ/692/L100
Title:
Relative photometry of WASP-10
Short Name:
J/ApJ/692/L100
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the photometry of WASP-10 during a transit of its short-period Jovian planet. We employed the novel point-spread function shaping capabilities of the Orthogonal Parallel Transfer Imaging Camera mounted on the UH 2.2m telescope to achieve a photometric precision of 4.7x10^-4^ per 1.3 minute sample. With this new light curve, in conjunction with stellar evolutionary models, we improve on existing measurements of the planetary, stellar, and orbital parameters. We find a stellar radius R_*_=0.698+/-0.012R_{sun}_ and a planetary radius R_P_=1.080+/-0.020R_Jup_. The quoted errors do not include any possible systematic errors in the stellar evolutionary models. Our measurement improves the precision of the planet's radius by a factor of 4, and revises the previous estimate downward by 16% (2.5{sigma}, where {sigma} is the quadrature sum of the respective confidence limits). Our measured radius of WASP-10b is consistent with previously published theoretical radii for irradiated Jovian planets.