- ID:
- ivo://CDS.VizieR/J/A+A/656/A88
- Title:
- TrES-5 photometric timeseries
- Short Name:
- J/A+A/656/A88
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The orbital motion of the transiting hot Jupiter TrES-5 b was reported to be perturbed by a planetary companion on a nearby orbit. Such compact systems do not frequently occur in nature, and learning their orbital architecture could shed some light on hot Jupiters' formation processes. We acquired fifteen new precise photometric time series for twelve transits of TrES-5 b between June 2019 and October 2020 using 0.9-2.0m telescopes. The method of precise transit timing was employed to verify the deviation of the planet from the Keplerian motion. Although our results show no detectable short-time variation in the orbital period of TrES-5 b and the existence of the additional nearby planet is not confirmed, the new transits were observed about two minutes earlier than expected. We conclude that the orbital period of the planet could vary in a long timescale. We found that the most likely explanation of the observations is the line-of-sight acceleration of the system's barycentre due to the orbital motion induced by a massive, wide-orbiting companion.
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- ID:
- ivo://CDS.VizieR/J/A+A/310/715
- Title:
- Tucana dwarf galaxy VI photometry
- Short Name:
- J/A+A/310/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep CCD photometry for the dwarf galaxy in Tucana (l=323, b=-47.4). The data indicate that the galaxy is dominated by an intermediate/old stellar population with metallicity similar to that of the galactic globular clusters NGC 6752 and NGC 7089 (M2) (we find [Fe/H]=~-1.56). The distance modulus we derived, (m-M)_V_=~24.72+/-0.2, makes clear that this galaxy belongs to the Local Gro up. Tucana is clearly different from other dwarf galaxies, such as Leo I (Lee et al., 1993AJ....106.1420L), or Phoenix (Ortolani and Gratton, 1988PASP..100.1405O), because there is no evidence of a young stellar population (t<=5Gyrs) We suggest that the Tucana Galaxy is a genuine dwarf spheroidal in which no recent burst of star formation occurred.
- ID:
- ivo://CDS.VizieR/J/A+AS/143/357
- Title:
- Tuorla Quasar Monitoring
- Short Name:
- J/A+AS/143/357
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observations presented in table 3 were made by using the 1.03m Dall-Kirkham-type telescope (f/8.45) of Tuorla Observatory with a SBIG ST-8 CCD-camera and a standard V-band filter. Table 4 includes data (B-, V- , and R-bands) observed at the Nordic Optical Telescope (NOT) on La Palma. Corrections for dark-current effects, additive effects (bias) and multiplicative effects (flatfield) were applied. Due to the relatively small field of view of the telescope separate frames of comparison stars were exposed for Mrk 421 and 4C 29.45. For the other objects normal differential photometry methods were applied. Exposure times with the Tuorla 1.03 meter telescope were between 60 and 240 seconds for objects brighter than 16 mag. For fainter objects, we have combined several exposures to achieve a sufficiently high signal to noise ratio.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A94
- Title:
- TU UMa light curves and maxima, CL Aur minima
- Short Name:
- J/A+A/589/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent statistical studies prove that the percentage of RR Lyrae pulsators that are located in binaries or multiple stellar systems is considerably lower than might be expected. This can be better understood from an in-depth analysis of individual candidates. We investigate in detail the light time effect of the most probable binary candidate TU UMa. This is complicated because the pulsation period shows secular variation. We model possible light time effect of TU UMa using a new code applied on previously available and newly determined maxima timings to confirm binarity and refine parameters of the orbit of the RRab component in the binary system. The binary hypothesis is also tested using radial velocity measurements. We used new approach to determine brightness maxima timings based on template fitting. This can also be used on sparse or scattered data. This approach was successfully applied on measurements from different sources. To determine the orbital parameters of the double star TU UMa, we developed a new code to analyse light time effect that also includes secular variation in the pulsation period. Its usability was successfully tested on CL Aur, an eclipsing binary with mass-transfer in a triple system that shows similar changes in the O-C diagram. Since orbital motion would cause systematic shifts in mean radial velocities (dominated by pulsations), we computed and compared our model with centre-of-mass velocities. They were determined using high-quality templates of radial velocity curves of RRab stars. Maxima timings adopted from the GEOS database (168) together with those newly determined from sky surveys and new measurements (85) were used to construct an O-C diagram spanning almost five proposed orbital cycles. This data set is three times larger than data sets used by previous authors. Modelling of the O-C dependence resulted in 23.3-year orbital period, which translates into a minimum mass of the second component of about 0.33Ms. Secular changes in the pulsation period of TU UMa over the whole O-C diagram were satisfactorily approximated by a parabolic trend with a rate of -2.2ms/yr. To confirm binarity, we used radial velocity measurements from nine independent sources. Although our results are convincing, additional long-term monitoring is necessary to unambiguously confirm the binarity of TU UMa.
- ID:
- ivo://CDS.VizieR/J/A+A/398/49
- Title:
- UBgRIJKs photometry in the FORS Deep Field
- Short Name:
- J/A+A/398/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FORS Deep Field project is a multi-colour, multi-object spectroscopic investigation of a 7' times 7' region near the south galactic pole based mostly on observations carried out with the FORS instruments attached to the VLT telescopes. It includes the QSO Q0103-260 (z=3.36). The goal of this study is to improve our understanding of the formation and evolution of galaxies in the young Universe. In this paper the field selection, the photometric observations, and the data reduction are described. The source detection and photometry of objects in the FORS Deep Field is discussed in detail. A combined B and I selected UBgRIJKs photometric catalog of 8753 objects in the FDF is presented and its properties are briefly discussed. The formal 50% completeness limits for point sources, derived from the coadded images, are 25.64, 27.69, 26.86, 26.68, 26.37, 23.60 and 21.57 in U, B, g, R, I, J and Ks (Vega-system), respectively. A comparison of the number counts in the FORS Deep Field to those derived in other deep field surveys shows very good agreement.
- ID:
- ivo://CDS.VizieR/J/MNRAS/352/285
- Title:
- u(bj)r & BV photometry of blue HB stars
- Short Name:
- J/MNRAS/352/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second in a series of papers presenting a new calculation of the mass of the Galaxy based on radial velocities and distances for a sample of faint 16<B<21.3 field blue horizontal-branch (BHB) stars. We present accurate BV CCD photometry and spectra for 142 candidate A-type stars selected from ubjr photometry of UK Schmidt telescope plates in six high-Galactic-latitude fields. Classification of these candidates produces a sample of 60 BHB stars at distances of 11-52kpc from the Sun (mean 28kpc), with heliocentric line-of-sight velocities accurate to 15km/s, and distance errors <10 per cent. We provide a summary table listing coordinates and velocities of these stars.
- ID:
- ivo://CDS.VizieR/J/AJ/128/544
- Title:
- UBRI Photometry of Quasars
- Short Name:
- J/AJ/128/544
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBRI photometry and spectra for 60 quasars found within 1{deg}^2^ centered on the J0053+1234 region, which has been the subject of the Caltech Faint Galaxy Redshift Survey. Candidate quasars were selected by their ultraviolet excess with respect to the stellar locus and confirmed spectroscopically. The quasars span a wide range in brightness (17.5<B<21.6) and redshift (0.43<z<2.38).
- ID:
- ivo://CDS.VizieR/J/AJ/100/1091
- Title:
- UBR photometry of 39 elliptical galaxies
- Short Name:
- J/AJ/100/1091
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained U,B, and R CCD surface photometry for a sample of 39 elliptical galaxies. For each galaxy we have determined the surface brightness profile, U-R and B-R color profiles, and the ellipticity and position angle profiles, all as function of major axis radius, using a two-dimensional ellipse fitting program. In addition, we have derived the sin and cos(3.theta) and 4.theta terms that describe the high-order deviations of the B and R isophotes from ellipses. While it is very common for ellipticals to display measurable 3.theta and 4.theta terms, the amplitudes of these terms rarely exceed 0.5%. The isophotes of elliptical galaxies are very well characterized by ellipses. The surface brightness and color profiles are given to radii at which the error in the profile reaches 0.1 mag from the uncertainty in the brightness of the night sky. We have carried out a series of simulations of the effects of seeing on luminosity and ellipticity profiles, to determine the radius beyond which the errors in our data from seeing are less than 0.05 mag and 0.02 in ellipticity. Measurable effects of seeing extend to surprisingly large radii, as much as 5-10 seeing radii, depending upon the ellipticity of the galaxy and the form of the surface brightness profile. Ellipticity and position angle profiles are usually the same in all passbands with no indication that the contours of constant color are more or less flattened than the isophotes, i.e., the isochromes and isophotes have the same shapes, but the insensitivity of the ellipticity to differences between these properties makes this a weak argument. The high-order terms, particularly the 3.theta terms, appear to be sensitive diagnostics for the existence of dust in ellipticals. We find that all the galaxies in this sample either become bluer in B-R and U-R with increasing radius or are of constant color. Mean values for the logarithmic gradients in color are -0.09 mag/arcsec2 per dex in radius in B-R, and -0.20 mag/arcsec2 per dex in radius in U-R. These color changes are consistent with a decrease in the [Fe/H] of approximately 0.20 per decade in radius. Surprisingly, there is no correlation of color gradient with luminosity. It is striking, however, that the lowest luminosity galaxies in the sample (i.e., those with M(B) > -20) do not show any color gradients. They have boxy isophotes, and are also rotationally flattened. While these properties may be related to the fact that they are companions of larger ellipsoidal systems, it could provide an important clue to the formation of ellipticals. Low luminosity ellipticals that are not close companions to giant ellipticals need to be studied.
- ID:
- ivo://CDS.VizieR/J/AJ/121/935
- Title:
- UBV and proper motions of Palomar 13
- Short Name:
- J/AJ/121/935
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a proper-motion, CCD photometric study of stars in the distant halo globular cluster Palomar 13. The absolute proper motion of Pal 13 with respect to the background galaxies, derived from moderate-scale photographic plates separated by a 40 year baseline, is (pmRAcosDE, pmDE)=(2.30, 0.27)+/-(0.26, 0.25)mas/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/391/179
- Title:
- UBV CCD photometry of NGC 1220
- Short Name:
- J/A+A/391/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBV CCD observations obtained in the field of the northern open cluster NGC 1220, for which little information is available. We provide also BV CCD photometry of a field 5' northward of NGC 1220 to take into account field star contamination. We argue that NGC 1220 is a young compact open cluster, for which we estimate a core radius in the range 1.5-2.0arcmin. We identify 26 likely candidate members with spectral type earlier than A5, down to V_0_=15.00mag on the basis of the position in the two-colour Diagram and in the Colour Magnitude Diagrams (CMDs). By analyzing the distribution of these stars in the colour-colour and CMDs, we find that NGC 1220 has a reddening E(B-V)=0.70+/-0.15mag, is placed 1800+/-200pc distant from the Sun, and has an age of about 60Myrs. The cluster turns out to be located about 120pc above the Galactic plane, relatively high with respect to its age.
