- ID:
- ivo://CDS.VizieR/J/other/RAA/19.41
- Title:
- TTVs & linear ephemerides of Kepler exoplanets
- Short Name:
- J/other/RAA/19.4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determined new linear ephemerides of transiting exoplanets using long-cadence de-trended data from quarters Q1 to Q17 of Kepler mission. We analysed TTV diagrams of 2098 extrasolar planets. The TTVs of 121 objects were excluded (because of insufficient data-points, influence of stellar activity, etc). Finally, new linear ephemerides of 1977 exoplanets from Kepler archive are presented. The significant linear trend was observed on TTV diagrams of approximately 35% of studied exoplanets. Knowing correct linear ephemeris is principal for successful follow-up observations of transits. Residual TTV diagrams of 64 analysed exoplanets shows periodic variation, 43 of these TTV planets were not reported yet.
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Search Results
- ID:
- ivo://CDS.VizieR/VI/107
- Title:
- Tubingen Ultraviolet Echelle Spectrometer
- Short Name:
- VI/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Tubingen Echelle Spectrograph (TUES), designed and managed at the University of Tubingen, flew on the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrograph (ORFEUS)-SPAS II space shuttle mission in 1996, returning spectra in the 900 Angstrom to 1400 Angstrom wavelength range. The instrument was designed to achieve a spectral resolution of 10000 when used with an entrance aperture of 10" diameter. During the 17.7 day flight, TUES returned 239 spectra of 62 targets.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A116
- Title:
- Tucana dSph CMD and star formation history
- Short Name:
- J/A+A/630/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a new star formation history for the Tucana dwarf spheroidal galaxy, obtained from a new look at a deep HST/ACS colour-magnitude diagram. We combined information from the main sequence turn-off and the horizontal branch to resolve the ancient star formation rates on a finer temporal scale than previously possible. We show that Tucana experienced three major phases of star formation, two very close together at ancient times and the last one ending between 6 and 8 Gyr ago. We show that the three discrete clumps of stars on the horizontal branch are linked to the distinct episodes of star formation in Tucana. The spatial distribution of the clumps reveals that each generation of stars presents a higher concentration than the previous one. The simultaneous modelling of the horizontal branch and the main sequence turn-off also allows us to measure the amount of mass lost by red giant branch stars in Tucana with unprecedented precision, confirming dwarf spheroidals to be excellent laboratories to study the advanced evolution of low-mass stars.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A152
- Title:
- Tucana dSph galaxy spectroscopic dataset
- Short Name:
- J/A+A/635/A152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Isolated local group (LG) dwarf galaxies have evolved most or all of their life unaffected by interactions with the large LG spirals and therefore offer the opportunity to learn about the intrinsic characteristics of this class of objects. Our aim is to explore the internal kinematic and metallicity properties of one of the three isolated LG early-type dwarf galaxies, the Tucana dwarf spheroidal. This is an intriguing system, as it has been found in the literature to have an internal rotation of up to 16km/s, a much higher velocity dispersion than dwarf spheroidals of similar luminosity, and a possible exception to the too-big-too-fail problem. We present the results of a new spectroscopic dataset that we procured from the Very Large Telescope (VLT) taken with the FORS2 instrument in the region of the Ca II triplet for 50 candidate red giant branch stars in the direction of the Tucana dwarf spheroidal. These yielded line-of-sight (l.o.s.) velocity and metallicity ([Fe/H]) measurements of 39 effective members that double the number of Tucana's stars with such measurements. In addition, we re-reduce and include in our analysis the other two spectroscopic datasets presented in the literature, the VLT/FORS2 sample by Fraternali et al. (2009A&A...499..121F), and the VLT/FLAMES one from Gregory et al. (2019MNRAS.485.2010G). Across the various datasets analyzed, we consistently measure a l.o.s. systemic velocity of 180+/-1.3km/s and find that a dispersion-only model is moderately favored over models that also account for internal rotation. Our best estimate of the internal l.o.s. velocity dispersion is 6.2_-1.3_^+1.6^km/s, much smaller than the values reported in the literature and in line with similarly luminous dwarf spheroidals; this is consistent with NFW halos of circular velocities <30km/s. Therefore, Tucana does not appear to be an exception to the too-big-to-fail problem, nor does it appear to reside in a dark matter halo much more massive than those of its siblings. As for the metallicity properties, we do not find anything unusual; there are hints of the presence of a metallicity gradient, but more data are needed to pinpoint its presence.
- 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/AJ/127/1588
- Title:
- 47 Tuc main-sequence star abundances
- Short Name:
- J/AJ/127/1588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of an analysis of CN and CH band strengths among a large sample of 47 Tucanae main-sequence and turnoff stars presented earlier by Harbeck et al. (2003, Cat. <J/AJ/125/197>).
- ID:
- ivo://CDS.VizieR/J/A+A/572/A108
- Title:
- 47 Tuc red giants chemical composition
- Short Name:
- J/A+A/572/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of chemical abundance patterns in globular clusters is of key importance to constrain the different candidates for intra-cluster pollution of light elements. We aim at deriving accurate abundances for a large range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Using tailored 1D LTE atmospheric models together with a combination of equivalent width measurements, LTE, and NLTE synthesis we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al and Ba. We find a mean [Fe/H]=-0.78+/-0.07 and [alpha/Fe]=0.34+/-0.03 in good agreement with previous studies. The remaining elements show good agreement with the literature, but the inclusion of NLTE for Al has a significant impact on the behaviour of this key element. We confirm the presence of an Na-O anti-correlation in 47 Tucanae found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to lower values, indicating that this may be overestimated in earlier works. No evidence for an intrinsic variation is found in any of the remaining elements.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/610
- Title:
- 47 Tuc sub-giant branch chemical abundances
- Short Name:
- J/MNRAS/459/610
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The globular cluster 47 Tuc exhibits a complex sub-giant branch (SGB) with a faint-SGB comprising only about the 10 per cent of the cluster mass and a bright-SGB hosting at least two distinct populations. We present a spectroscopic analysis of 62 SGB stars including 21 faint-SGB stars. We thus provide the first chemical analysis of the intriguing faint-SGB population and compare its abundances with those of the dominant populations. We have inferred abundances of Fe, representative light elements C, N, Na, and Al, {alpha} elements Mg and Si for individual stars. Oxygen has been obtained by co-adding spectra of stars on different sequences. In addition, we have analysed 12 stars along the two main RGBs of 47 Tuc. Our principal results are (i) star-to-star variations in C/N/Na among RGB and bright-SGB stars; (ii) substantial N and Na enhancements for the minor population corresponding to the faint-SGB; (iii) no high enrichment in C+N+O for faint-SGB stars. Specifically, the C+N+O of the faint-SGB is a factor of 1.1 higher than the bright-SGB, which, considering random (+/-1.3) plus systematic errors (+/-0.3), means that their C+N+O is consistent within observational uncertainties. However, a small C+N+O enrichment for the faint-SGB, similar to what predicted on theoretical ground, cannot be excluded. The N and Na enrichment of the faint-SGB qualitatively agrees with this population possibly being He-enhanced, as suggested by theory. The iron abundance of the bright and faint-SGB is the same to a level of ~0.10dex, and no other significant difference for the analysed elements has been detected.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/527
- Title:
- Tully-Fisher distances for Spitzer galaxies
- Short Name:
- J/MNRAS/444/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper involves a data release of the observational campaign: Cosmicflows with Spitzer (CFS). Surface photometry of the 1270 galaxies constituting the survey is presented. An additional ~400 galaxies from various other Spitzer surveys are also analysed. CFS complements the Spitzer Survey of Stellar Structure in Galaxies, that provides photometry for an additional 2352 galaxies, by extending observations to low galactic latitudes (|b|<30{deg}). Among these galaxies are calibrators, selected in the K band, of the Tully-Fisher relation. The addition of new calibrators demonstrates the robustness of the previously released calibration. Our estimate of the Hubble constant using supernova host galaxies is unchanged, H_0_=75.2+/-3.3km/s/Mpc. Distance-derived radial peculiar velocities, for the 1935 galaxies with all the available parameters, will be incorporated into a new data release of the Cosmicflows project. The size of the previous catalogue will be increased by 20 percent, including spatial regions close to the Zone of Avoidance.
- ID:
- ivo://CDS.VizieR/J/AJ/118/1489
- Title:
- Tully-Fisher peculiar velocities in 52 clusters
- Short Name:
- J/AJ/118/1489
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained I-band Tully-Fisher (T-F) measurements for 522 late-type galaxies in the fields of 52 rich Abell clusters distributed throughout the sky between ~50 and 200h^-1^Mpc. Here we estimate corrections to the data for various forms of observational bias, most notably Malmquist and cluster population incompleteness bias. The bias-corrected data are applied to the construction of an I-band T-F template, resulting in a relation with a dispersion of 0.38mag and a kinematic zero point accurate to 0.02mag. This represents the most accurate T-F template relation currently available. Individual cluster T-F relations are referred to the average template relation to compute cluster peculiar motions. The line-of-sight dispersion in the peculiar motions is 341x93km/s, in general agreement with that found for the cluster sample of Giovanelli and coworkers.