VVV survey near-infrared colour catalogue of known variable stars

Herpich, F. R.; Lopes, C. E. Ferreira; Saito, R. K.; Minniti, D.; Ederoclite, A.; Ferreira, T. S.; Catelan, M.

doi:10.1051/0004-6361/201834356

Cited by 7 publications

(5 citation statements)

References 46 publications

(21 reference statements)

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“…Disk tile names are labeled by a d followed by an ID number ranging between 001 and 152; bulge tiles are instead denoted by a b, followed by an ID number in the range 201-396 (e.g., Catelan et al 2011;Saito et al 2012). Due to the very high stellar density in our studied fields, we consider point-spread function (PSF) photometry to be superior to aperture photometry, as adopted in some previous variability studies that also used VVV data (e.g., Saito et al 2013;Teixeira et al 2018;Dékány et al 2019;Ferreira Lopes et al 2020;Herpich et al 2021). Accordingly, PSF photometry was obtained for all sources by fitting appropriate models on individual pawprint images, using the daophot/allstar software package (Stetson 1987).…”

Section: Observations and Data Reductionmentioning

confidence: 99%

The VVV survey: Long-period variable stars

Nikzat

Lopes

Catelan

et al. 2022

A&A

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Context. Long-period variable stars (LPVs) are pulsating red giants, primarily in the asymptotic giant branch phase, and they include both Miras and semi-regular variables (SRVs). Their period-age and period-luminosity relations enable us to trace different stellar populations, as they are intrinsically very bright and cover a wide range in distances and ages. Aims. The purpose of this study is to establish a census of LPV stars in a region close to the Galactic center, using the six-year database of the Vista Variables in the Vía Láctea (VVV) ESO Public Survey, as well as to describe the methodology that was employed to search for and characterize LPVs using VVV data. Near-IR surveys such as VVV provide a unique opportunity to probe the high-extinction innermost regions of the Milky Way. The detection and analysis of the intrinsically bright Miras in this region could provide us with an excellent probe of the properties of the Milky Way far behind its bulge. Methods. We used point-spread function photometry for all available Ks-band images in ten VVV tiles, covering 16.4 deg2 in total, overlapping fields observed in the course of the Optical Gravitational Lensing Experiment (OGLE)-III survey. We designed a method to select LPV candidates, and we used the known variables from OGLE-III and other known variables from the literature to test our approach. The reduced χ2 statistic, along with the flux-independent index K(fi), were used in our analysis. The Lomb-Scargle period search method, Fourier analysis, template fitting, and visual inspection were then performed to refine our sample and characterize the properties of the stars included in our catalog. Results. A final sample of 130 Mira candidates, of which 129 are new discoveries, was thus obtained, with periods in the range between about 80 and 1400 days. Moreover, a sample of 1013 LPV candidates is also presented, whose periods are however not sufficiently constrained by the available data. A fraction of the latter may eventually turn out to be SRVs. Ages are measured for these stars based on a reassessment of the period-age relations available in the literature. The Miras in our catalog include 18 stars satisfying the requirements to serve as reliable distance indicators and which are not saturated in the VVV Ks-band images. Their distances are accordingly derived and discussed. A number of objects that are seemingly placed far behind the Milky Way’s bulge was detected.

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Section: Observations and Data Reductionmentioning

confidence: 99%

The VVV survey: Long-period variable stars

Nikzat

Lopes

Catelan

et al. 2022

A&A

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“…As a result, catalogues of RR Lyrae stars along the Southern Galactic Plane (Dékány et al 2018), inner bulge , outer bulge (Gran et al 2016) and 100 arcmin from the Galactic Centre (Minniti et al 2016;Contreras Ramos et al 2018) have been compiled for analysis. Similarly, VISTA Variables in the Vía Láctea infrared variability catalogue (VIVA, Ferreira Lopes et al 2020) provides a near complete variability census for the Galactic Bulge, whilst Herpich et al (2021) have presented an analysis of previously known variable sources in VVV. These catalogues paired with preliminary results on the RR Lyrae star distribution (Cabral et al 2020), novae (Saito et al 2013) and the composite bulge structure of the Milky Way (Dékány et al 2013b) Variable star classification with VVV 3 tific merit of the VVV project.…”

Section: Introductionmentioning

confidence: 99%

Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey

Molnar

Sanders

Smith

et al. 2021

Monthly Notices of the Royal Astronomical Society

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We present VIVACE, the VIrac VAriable Classification Ensemble, a catalogue of variable stars extracted from an automated classification pipeline for the Vista Variables in the Vía Láctea (VVV) infrared survey of the Galactic bar/bulge and southern disc. Our procedure utilises a two-stage hierarchical classifier to first isolate likely variable sources using simple variability summary statistics and training sets of non-variable sources from the Gaia early third data release, and then classify candidate variables using more detailed light curve statistics and training labels primarily from OGLE and VSX. The methodology is applied to point-spread-function photometry for ∼490 million light curves from the VIRAC v2 astrometric and photometric catalogue resulting in a catalogue of ∼1.4 million likely variable stars, of which ∼39, 000 are high-confidence (classification probability >0.9) RR Lyrae ab stars, ∼8000 RR Lyrae c/d stars, ∼187, 000 detached/semi-detached eclipsing binaries, ∼18, 000 contact eclipsing binaries, ∼1400 classical Cepheid variables and ∼2200 Type II Cepheid variables. Comparison with OGLE-4 suggests a completeness of around 90 per cent for RRab and ≲ 60 per cent for RRc/d, and a misclassification rate for known RR Lyrae stars of around 1 per cent for the high confidence sample. We close with two science demonstrations of our new VIVACE catalogue: first, a brief investigation of the spatial and kinematic properties of the RR Lyrae stars within the disc/bulge, demonstrating the spatial elongation of bar-bulge RR Lyrae stars is in the same sense as the more metal-rich red giant population whilst having a slower rotation rate of ∼40 km s−1kpc−1; and secondly, an investigation of the Gaia EDR3 parallax zeropoint using contact eclipsing binaries across the Galactic disc plane and bulge.

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“…where we use R JK = 0.428 ± 0.04 mag in the VISTA bands (Alonso-García et al 2018) and adopt K s and color index (J − K s ) values from Herpich et al (2021). We calculate an absolute W JK = 3.671 ± 0.062 mag from the PLR relation of Jayasinghe et al (2020), and the distance is estimated from the distance modulus to be 1740 pc.…”

Section: Ogle104mentioning

confidence: 99%

Three Ultra-short-period Contact Eclipsing Binary Systems Mined from Massive Astronomical Surveys

Παπαγεωργίου

Christopoulou

Lopes

et al. 2023

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We present the photometric analysis of three ultra-short-period total eclipsing binaries in contact configuration, CRTS_J172718.0+431624, OGLE-BLG-ECL-000104, and OGLE-BLG-ECL-000012, mined from massive astronomical surveys. Using the available archival light curves (LCs) from Vista Variables in the Vía Láctea (VVV), Optical Gravitational Lensing Experiment (OGLE), Zwicky Transient Facility, and Catalina Sky Survey in different passbands and new multiband photometric observations with the 2.3 m Aristarchos telescope at Helmos Observatory, their relative physical parameters were derived. We explored the parameter space by using the PIKAIA genetic algorithm optimizer. The best photometric solution and error budget estimation were adopted for each system through Markov Chain Monte Carlo sampling of the global optimum. The approximate absolute parameters were derived for each contact system adopting an empirical mass–luminosity relation. All three systems have a mass ratio lower than 0.5. The exchange between the primary and secondary depths of CRTS_J172718.0+431624 during 2016–2022 may be due to spot activity. In addition, we present a detailed analysis of the first well-characterized shortest-period contact eclipsing binary with total eclipses known so far (OGLE-BLG-ECL-000104). Thanks to VVV and OGLE LCs, new distances were derived for OGLE-BLG-ECL-000104 and OGLE-BLG-ECL-000012 using empirical period–luminosity relations. The origin and evolutionary status of all three ultra-short-period contact binaries are thoroughly discussed in the context of the detached binary formation channel.

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VVV survey near-infrared colour catalogue of known variable stars

Cited by 7 publications

References 46 publications

The VVV survey: Long-period variable stars

The VVV survey: Long-period variable stars

Variable star classification across the Galactic bulge and disc with the VISTA Variables in the Vía Láctea survey

Three Ultra-short-period Contact Eclipsing Binary Systems Mined from Massive Astronomical Surveys

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