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- ID:
- ivo://CDS.VizieR/J/MNRAS/405/1770
- Title:
- LMC red giants in E sequence
- Short Name:
- J/MNRAS/405/1770
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied a sample of Large Magellanic Cloud red giant binaries that lie on sequence E in the period-luminosity plane. We show that their combined light and velocity curves unambiguously demonstrate that they are binaries showing ellipsoidal variability. By comparing the phased light and velocity curves of both sequence D and E variables, we show that the sequence D variation - the long secondary period - is not caused by ellipsoidal variability. We also demonstrate several further differences between stars on sequences D and E. These include differences in velocity amplitude, in the distribution of eccentricity and in the correlations of velocity amplitude with luminosity and period. We also show that the sequence E stars, unlike stars on sequence D, do not show any evidence of a mid-infrared excess that would indicate circumstellar dust.
- ID:
- ivo://CDS.VizieR/J/A+A/423/97
- Title:
- LMC RR Lyrae radial velocities
- Short Name:
- J/A+A/423/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediate resolution spectra and infrared images were obtained with FORS1 at the ESO VLT and with the SOFI infrared imager at the ESO NTT.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3034
- Title:
- LMC Type II Cepheids J and Ks light curves
- Short Name:
- J/MNRAS/446/3034
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The VISTA (Visible and Infrared Survey Telescope for Astronomy) survey of the Magellanic Clouds System (VMC) is collecting deep Ks-band time-series photometry of the pulsating variable stars hosted in the system formed by the two Magellanic Clouds and the Bridge connecting them. In this paper, we have analysed a sample of 130 Large Magellanic Cloud (LMC) Type II Cepheids (T2CEPs) found in tiles with complete or near-complete VMC observations for which identification and optical magnitudes were obtained from the OGLE III (Optical Gravitational Lensing Experiment) survey. We present J and Ks light curves for all 130 pulsators, including 41 BL Her, 62 W Vir (12 pW Vir) and 27 RV Tau variables. We complement our near-infrared photometry with the V magnitudes from the OGLE III survey, allowing us to build a variety of period-luminosity (PL), period-luminosity-colour (PLC) and period-Wesenheit (PW) relationships, including any combination of the V, J, Ks filters and valid for BL Her and W Vir classes. These relationships were calibrated in terms of the LMC distance modulus, while an independent absolute calibration of the PL(Ks) and the PW(Ks, V) was derived on the basis of distances obtained from Hubble Space Telescope parallaxes and Baade-Wesselink technique. When applied to the LMC and to the Galactic globular clusters hosting T2CEPs, these relations seem to show that (1) the two Population II standard candles RR Lyrae and T2CEPs give results in excellent agreement with each other; (2) there is a discrepancy of ~0.1mag between Population II standard candles and classical Cepheids when the distances are gauged in a similar way for all the quoted pulsators. However, given the uncertainties, this discrepancy is within the formal 1{sigma} uncertainties.
- ID:
- ivo://CDS.VizieR/J/MNRAS/397/933
- Title:
- LMC type II Cepheids JHKs magnitudes
- Short Name:
- J/MNRAS/397/933
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKs magnitudes corrected to mean intensity are estimated for Large Magellanic Cloud (LMC) type II Cepheids in the OGLE-III survey the third phase of the Optical Gravitational Lensing Experiment (OGLE). Period-luminosity (PL) relations are derived in JHKs as well as in a reddening-free VI parameter. Within the uncertainties, the BL Her stars (P<4d) and the W Vir stars (P=4 to 20d) are colinear in these PL relations. The slopes of the infrared relations agree with those found previously for type II Cepheids in globular clusters within the uncertainties.
- ID:
- ivo://CDS.VizieR/J/ApJ/678/865
- Title:
- LONEOS-I RR Lyrae stars
- Short Name:
- J/ApJ/678/865
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 838 ab-type RR Lyrae stars from the Lowell Observatory Near Earth Objects Survey Phase I (LONEOS-I). These objects cover 1430deg^2^ and span distances ranging from 3 to 30kpc from the Galactic center. Object selection is based on phased, photometric data with 28-50 epochs. We use this large sample to explore the bulk properties of the stellar halo, including the spatial distribution. The period-amplitude distribution of this sample shows that the majority of these RR Lyrae stars resemble Oosterhoff type I, but there is a significant fraction (26%) which have longer periods and appear to be Oosterhoff type II. We find that the radial distributions of these two populations have significantly different profiles ({rho}_OoI_~R^-2.26+/-0.07^ and {rho}_OoII_~R^-2.88+/-0.11^). This suggests that the stellar halo was formed by at least two distinct accretion processes and supports dual-halo models.
467. Long period Cepheids
- ID:
- ivo://CDS.VizieR/J/A+A/314/541
- Title:
- Long period Cepheids
- Short Name:
- J/A+A/314/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The light curves of 124 classical Cepheids with period longer than 8 days were Fourier decomposed with the aim of detecting resonance effects between pulsation modes in the Fourier parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/532/A78
- Title:
- Long-period variables in NGC 147 and NGC 185
- Short Name:
- J/A+A/532/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Previous studies on the stellar content of the two nearby dwarf galaxies NGC 147 and NGC 185 reveal a rich population of late-type giants in both systems, including a large number of carbon-rich objects. These stars are known to show pronounced photometric variability, which can be used for a more detailed characterisation of these highly evolved stars. Owing to their well-studied parameters, these Local Group members are ideal candidates for comparative studies. Through photometric monitoring, we attempt to provide a catalogue of long-period variables (LPVs), including Mira variables, semi-regular variables, and even irregular variables in NGC 147 and NGC 185. We investigate the light variations and compare the characteristics of these two LPV populations with the results found for other galaxies, such as the LMC.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A111
- Title:
- Long period variables in omega Cen
- Short Name:
- J/A+A/585/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent studies have detected multiple populations in globular clusters. The massive globular cluster {omega} Cen hosts at least three populations of different metallicity. The most metal-rich one is thought to show also an overabundance of He. These differences should become visible in the structure, evolution, and pulsation of its stars. We aim to study the effects of the different starting compositions of the three populations in {omega} Cen on the most luminous red giants in this cluster. The long-periodic variability of evolved stars in {omega} Cen opens a comparably easy access window to the structure and composition of these objects. We made a detailed search for long-period variables (LPVs) in {omega} Cen leading to the detection of many new variables and period determinations for a significant number of them. Periods and luminosities were then compared with the most recent pulsation models for these kinds of stars.
- ID:
- ivo://CDS.VizieR/J/other/RAA/18.137
- Title:
- Long-term BVRI photometry of 15 PMS stars
- Short Name:
- J/other/RAA/18.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper reports results from the multicolor photometric observations of 15 pre-main sequence stars collected in the period September 2010 - October 2017. The stars from our study are located in the star-forming HII region IC 5070. These objects were previously detected as either emission line stars, flare stars, T Tauri variables or Herbig Ae/Be stars. Photometric observations, especially concerning the long-term behavior of the objects, are missing in the literature. We present the first photometric monitoring for all stars from our study. The analysis of the obtained BVRI photometric data allows us to draw the conclusion that all investigated objects are variable stars. In the case of LkHa 146, we identified previously unknown periodicity in its photometric variability.
