- ID:
- ivo://CDS.VizieR/J/AJ/154/263
- Title:
- NIR photometry of 77 RR Lyrae stars
- Short Name:
- J/AJ/154/263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained single-phase near-infrared (NIR) magnitudes in the J and K bands for 77 RR Lyrae (RRL) stars in the Fornax Dwarf Spheroidal Galaxy. We have used different theoretical and empirical NIR period-luminosity-metallicity calibrations for RRL stars to derive their absolute magnitudes, and found a true, reddening-corrected distance modulus of 20.818+/-0.015(statistical)+/-0.116(systematic) mag. This value is in excellent agreement with the results obtained within the Araucaria Project from the NIR photometry of red clump stars (20.858+/-0.013 mag), the tip of the red giant branch (20.84+/-0.04+/-0.14 mag), as well as with other independent distance determinations to this galaxy. The effect of metallicity and reddening is substantially reduced in the NIR domain, making this method a robust tool for accurate distance determination at the 5% level. This precision is expected to reach the level of 3% once the zero points of distance calibrations are refined thanks to the Gaia mission. NIR period-luminosity-metallicity relations of RRL stars are particularly useful for distance determinations to galaxies and globular clusters up to 300 kpc, that lack young standard candles, like Cepheids.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/211/3
- Title:
- NIR photometry variability in {rho} Oph
- Short Name:
- J/ApJS/211/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Presented are the results of a near-IR photometric survey of 1678 stars in the direction of the {rho} Ophiuchus ({rho} Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and Ks-band photometric measurements with a cadence of ~1 day are obtained over three observing seasons spanning ~2.5 yr; it is the most intensive survey of stars in this region to date. This survey identifies 101 variable stars with {Delta}Ks-band amplitudes from 0.044 to 2.31 mag and {Delta}(J-Ks) color amplitudes ranging from 0.053 to 1.47 mag. Of the 72 young {rho} Oph star cluster members included in this survey, 79% are variable; in addition, 22 variable stars are identified as candidate members. Based on the temporal behavior of the Ks time-series, the variability is distinguished as either periodic, long time-scale or irregular. This temporal behavior coupled with the behavior of stellar colors is used to assign a dominant variability mechanism. A new period-searching algorithm finds periodic signals in 32 variable stars with periods between 0.49 to 92 days. The chief mechanism driving the periodic variability for 18 stars is rotational modulation of cool starspots while 3 periodically vary due to accretion-induced hot spots. The time-series for six variable stars contains discrete periodic "eclipse-like" features with periods ranging from 3 to 8 days. These features may be asymmetries in the circumstellar disk, potentially sustained or driven by a proto-planet at or near the co-rotation radius. Aperiodic, long time-scale variations in stellar flux are identified in the time-series for 31 variable stars with time-scales ranging from 64 to 790 days. The chief mechanism driving long time-scale variability is variable extinction or mass accretion rates. The majority of the variable stars (40) exhibit sporadic, aperiodic variability over no discernable time-scale. No chief variability mechanism could be identified for these variable stars.
- ID:
- ivo://CDS.VizieR/II/287
- Title:
- Northern Sky Variability Survey (NSVS)
- Short Name:
- II/287
- Date:
- 23 Nov 2021 00:31:33
- Publisher:
- CDS
- Description:
- The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the first-generation Robotic Optical Transient Search Experiment (ROTSE-I) using a robotic system of four comounted unfiltered telephoto lenses equipped with CCD cameras. The survey was conducted from Los Alamos, New Mexico, and primarily covers the entire northern sky. Some data in southern fields between declinations 0{deg} and -38{deg} are also available, although with fewer epochs and noticeably lesser quality. The NSVS contains light curves for approximately 14 million objects. With a 1-yr baseline and typically 100-500 measurements per object, the NSVS is the most extensive record of stellar variability across the bright sky available today. In a median field, bright unsaturated stars attain a point-to-point photometric scatter of ~0.02mag and position errors within 2. At Galactic latitudes |b|<20{deg}, the data quality is limited by severe blending due to the ~14" pixel size. We present basic characteristics of the data set and describe data collection, analysis, and distribution. All NSVS photometric measurements are available for on-line public access from the Sky Database for Objects in Time-Domain (SkyDOT) at Los Alamos National Laboratory. Copies of the full survey photometry may also be requested on tape.
- ID:
- ivo://CDS.VizieR/J/AJ/114/1190
- Title:
- NSV 09295: A double-mode RR Lyrae
- Short Name:
- J/AJ/114/1190
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of more than 2000 CCD observations of the field RR Lyrae star NSV 09295 shows that the star is a double-mode RR Lyrae (RRd) variable with P_0_=0.46334d and P_1_=0.34423d. This brings the total of known field RRd stars in the Milky Way galaxy to four. These four variables are compared with the RRd stars in galactic globular clusters and with the field RRd stars in the LMC, and in the Draco and Sculptor dwarf galaxies. It appears that all known RRd stars have a metal abundance of less than [Fe/H]=-1.6. (c) 1997 American Astronomical Society.
- ID:
- ivo://CDS.VizieR/J/PASP/123/1149
- Title:
- NSV 11154 BVRI light curves
- Short Name:
- J/PASP/123/1149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NSV 11154 has been confirmed as a new member of the rare hydrogen- deficient R Coronae Borealis (RCB) stars based on new photometric and spectroscopic data. Using new photometry, as well as archival plates from the Harvard archive, we have constructed the historical lightcurve of NSV 11154 from 1896 to the present. The lightcurve shows the sudden, deep, irregularly spaced declines characteristic of RCB stars.
- ID:
- ivo://CDS.VizieR/J/AJ/138/466
- Title:
- NSVS variables automated classification
- Short Name:
- J/AJ/138/466
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 4659 variable objects in the Northern Sky Variability Survey. We have classified each of these objects into one of the five variable star classes: (1) Algol/alpha Lyr systems including semidetached, and detached eclipsing binaries, (2) W Ursae Majoris overcontact and ellipsoidal variables, (3) long-period variables such as Cepheid and Mira-type objects, (4) RR Lyr pulsating variables, and (5) short-period variables including delta Scuti stars. All the candidates have outside of eclipse magnitudes of ~10-13.
- ID:
- ivo://CDS.VizieR/J/ApJS/168/289
- Title:
- NUV spectrum of eta Car in 2003.5
- Short Name:
- J/ApJS/168/289
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) near-ultraviolet (NUV) echelle spectra reveal complex structure in the sight line toward the Weigelt D condensation located 0.25" north-northwest of {eta} Car. This analysis uses data recorded between 2000 October and 2004 March to monitor changes in emission and absorption as the UV photoexciting fluxes from {eta} Car drop and later reappear. We compare changes in the wind profiles seen against the star and the CS absorptions to gain knowledge of the properties of the extended wind and the ejecta. Complete spectra, in the wavelength region 2424-2706{AA}, with line identifications are available in the electronic edition of this paper.
- ID:
- ivo://CDS.VizieR/J/AZh/92/406
- Title:
- NZ Boo V light curves
- Short Name:
- J/AZh/92/406
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of V photometric light curves of the eclipsing cataclysmic variable SDSS J150240.98+333423.9/NZ Boo obtained in April-June, 2012 with a CCD photometer using the 60-cm telescope of the Sternberg Astronomical Institute's Crimean station is presented (based on more than 750 images). The first observation was made ~350-370 orbital cycles after the beginning of the outburst of April 2012; all the observations correspond to quiescence of the system. The orbital period, P = 0.0589106(4)d, changed by no more than {Delta}Porb/Porb~2x10^-5^ during the more than 37200 orbital cycles since the previous observations of the system.
- ID:
- ivo://CDS.VizieR/J/A+A/526/A44
- Title:
- Observations of II Peg
- Short Name:
- J/A+A/526/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/1744
- Title:
- Observations of RR Lyr stars in M5
- Short Name:
- J/MNRAS/411/1744
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The period changes of 86 M5 RR Lyrae stars have been investigated on a 100-yr time base. The published observations have been supplemented by archival Asiago, Konkoly and Las Campanas photographic observations obtained between 1952 and 1993.
