- ID:
- ivo://CDS.VizieR/J/AJ/134/973
- Title:
- SDSS Stripe 82 star catalogs
- Short Name:
- J/AJ/134/973
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a standard star catalog constructed using multiple SDSS photometric observations (at least four per band, with a median of 10) in the ugriz system. The catalog includes 1.01 million nonvariable unresolved objects from the equatorial stripe 82 (|{delta}_J2000.0_|<1.266{deg}) in the right ascension range 20^h^34^m^-4^h^00^m^ and with the corresponding r-band (approximately Johnson V-band) magnitudes in the range 14-22. The distributions of measurements for individual sources demonstrate that the photometric pipeline correctly estimates random photometric errors, which are below 0.01mag for stars brighter than 19.5, 20.5, 20.5, 20, and 18.5 in ugriz, respectively (about twice as good as for individual SDSS runs). Several independent tests of the internal consistency suggest that the spatial variation of photometric zero points is not larger than ~0.01mag (rms). In addition to being the largest available data set with optical photometry internally consistent at the ~1% level, this catalog provides a practical definition of the SDSS photometric system. Using this catalog, we show that photometric zero points for SDSS observing runs can be calibrated within a nominal uncertainty of 2% even for data obtained through 1mag thick clouds, and we demonstrate the existence of He and H white dwarf sequences using photometric data alone. Based on the properties of this catalog, we conclude that upcoming large-scale optical surveys such as the Large Synoptic Survey Telescope will be capable of delivering robust 1% photometry for billions of sources.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/385/488
- Title:
- Search for duplicity in periodic Be stars
- Short Name:
- J/A+A/385/488
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Four Be stars, HR 1960, HR 2968, HR 3237 and HR 3642, selected according to their periodic variations in Hipparcos and Geneva photometries, have been monitored from 1998 until 2001 with the Coralie spectrograph. HR 1960 and HR 3237 are two new spectroscopic binaries, HR 3642 is a new lambda Eri star, and HR 2968 is stable.
- ID:
- ivo://CDS.VizieR/J/AJ/112/742
- Title:
- Search for RR Lyrae Variables
- Short Name:
- J/AJ/112/742
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We searched the CCD/Transit Instrument (CTI) survey databases for RR Lyrae variable stars. The CTI images a strip of the sky with a narrow spread of declination over all right ascensions. The resulting survey area covers a large range of both Galactic latitude and longitude, amounting to approximately 50deg^2. We detected a total of 42 RR Lyrae stars to a faint limiting magnitude of V=19. Thirty-four of these RR Lyae stars are newly discovered.
- ID:
- ivo://CDS.VizieR/J/AJ/136/259
- Title:
- Second GALEX UV variability catalog (GUVV-2)
- Short Name:
- J/AJ/136/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second Galaxy Evolution Explorer (GALEX) Ultraviolet Variability (GUVV-2) Catalog, which contains information on 410 newly discovered time-variable sources gained through simultaneous near UV (NUV 1750-2750{AA}) and far-UV (FUV 1350-1750{AA}) photometric observations. Source variability was determined by comparing the NUV and/or FUV fluxes derived from orbital exposures recorded during a series of multiple observational visits to 169 GALEX fields on the sky.
- ID:
- ivo://CDS.VizieR/J/AJ/130/776
- Title:
- Secular evolution in Mira variable pulsations
- Short Name:
- J/AJ/130/776
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the results of our study of period change in 547 Mira variables using data from the AAVSO (American Association of Variable Star Observers). We use wavelet analysis to measure the period changes in individual Mira stars over the span of available data. By making linear fits to the period versus time measurements, we determine the average rates of period change, d(lnP)/dt, for each of these stars.
- ID:
- ivo://CDS.VizieR/J/AJ/147/140
- Title:
- SED of 24 class I and class II FU Orionis stars
- Short Name:
- J/AJ/147/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ~80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ~10^-7^M_{sun}_/yr versus ~10^-5^M_{sun}_/yr for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (~70%) have envelope mass accretion rates above 10^-7^M_{sun}_/yr. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A66
- Title:
- Semi-regular red giants as distance indicators
- Short Name:
- J/A+A/656/A66
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Semi-regular variables (SRVs) are similar to Miras in brightness, and they also follow PLRs, though not necessarily the same as Miras. As potential standard candles they are more challenging than Miras due to their smaller variability amplitudes and less regular light curves, but they are substantially more numerous and especially promising to probe old stellar populations. We aim to characterize the variability of SRVs, with focus on their connection with Miras, in order to prepare the ground for investigating their potential as distance indicators. We examine SRVs and Miras in the Magellanic Clouds from OGLE-III observations, with data from Gaia and 2MASS. After cleaning the sample from variability periods unrelated to pulsation, we classify each source by chemical type and combination of pulsation modes. We examine the results in terms of global photometric and pulsation properties. We identify four SRVs groups that fit the general evolutionary scenario predicted by theory. SRVs dominated by fundamental-mode pulsation are very similar to Miras, especially if mono-periodic. They further split into two sub-groups, one of which follows the same sequence as Miras in the period-luminosity and period-amplitude diagram, without discontinuity. The similarities between Miras and SRVs suggest that the latter can be adopted as complementary distance indicators to the former, thereby at least doubling the available number of LPVs suitable for use as distance indicators. The traditional amplitude-based separation between Miras and SRVs is not necessarily appropriate, and a more physically sound criterion should also involve pulsation periods. While this would require comparatively longer time series, they are expected to become accessible in the coming years even for weak sources thanks to current and future large-scale surveys. The table of reclassified LPVs is made public.
- ID:
- ivo://CDS.VizieR/J/A+A/296/727
- Title:
- Semiregular variables H2O maser
- Short Name:
- J/A+A/296/727
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 107 semiregular variables of spectral type M have been observed in the H2O 6(16)-5(23) line at 22.235GHz with the 100m Effelsberg radio telescope and maser emission has been detected in 23 objects, of which 10 are new detections.
- ID:
- ivo://CDS.VizieR/J/ApJ/552/289
- Title:
- Semiregular variable stars in Baade's windows
- Short Name:
- J/ApJ/552/289
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By cross-correlating the results of two recent large-scale surveys, the general properties of a well-defined sample of semiregular variable stars have been determined. ISOGAL mid-infrared photometry (7 and 15{mu}m and MACHO V and R light curves are assembled for approximately 300 stars in the Baade's windows of low extinction toward the Galactic bulge. These stars are mainly giants of late M spectral type, evolving along the asymptotic giant branch (AGB). They are found to possess a wide and continuous distribution of pulsation periods and to obey an approximate logP-M_bol_ relation or set of such relations.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A63
- Title:
- Semi-sinusoidal variability with CoRoT
- Short Name:
- J/A+A/555/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To date, the CoRoT space mission has produced more than 124471 light curves. Classifying these curves in terms of unambiguous variability behavior is mandatory for obtaining an unbiased statistical view on their controlling root-causes. The present study provides an overview of semi-sinusoidal light curves observed by the CoRoT exo-field CCDs. We selected a sample of 4206 light curves presenting well-defined semi-sinusoidal signatures. The variability periods were computed based on Lomb-Scargle periodograms, harmonic fits, and visual inspection.
