- ID:
- ivo://CDS.VizieR/J/A+A/642/A225
- Title:
- Faculae-Spot dominance & rotation periods
- Short Name:
- J/A+A/642/A225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar rotation periods can be determined by observing brightness variations caused by active magnetic regions transiting visible stellar disk as the star rotates. The successful stellar photometric surveys stemming from the Kepler and TESS observations led to the determination of rotation periods in tens of thousands of young and active stars. However, there is still a lack of information about rotation periods of older and less active stars, like the Sun. The irregular temporal profiles of light curves caused by the decay times of active regions, which are comparable to or even shorter than stellar rotation periods, combine with the random emergence of active regions to make period determination for such stars very difficult. We tested the performance of the new method for the determination of stellar rotation periods against stars with previously determined rotation periods. The method is based on calculating the gradient of the power spectrum (GPS) and identifying the position of the inflection point (i.e. point with the highest gradient). The GPS method is specifically aimed at determining rotation periods of low-activity stars like the Sun. We applied the GPS method to Sun-like stars observed by the Kepler telescope. We separately considered two stellar samples: one with near-solar rotation periods (24-27.4d) and broad range of effective temperatures (5000-6000K), another with near-solar effective temperatures (5700-5900K) and broad range of rotation periods (15-40d). We show that the GPS method returns precise values of stellar rotation periods. Furthermore, it allows us to constrain the ratio between facular and spot areas of active regions at the moment of their emergence. We show that relative facular area decreases with stellar rotation rate. Our results suggest that the GPS method can be successfully applied to retrieve periods of stars with both regular and non-regular light curves.
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6012. FAI archives TAP service
- ID:
- ivo://fai.kz/tap
- Title:
- FAI archives TAP service
- Short Name:
- FAI NVO DC TAP
- Date:
- 10 May 2024 15:28:03
- Publisher:
- Fesenkov Astrophysical Institute
- Description:
- The FAI archives's TAP end point. The Table Access Protocol (TAP) lets you execute queries against our database tables, inspect various metadata, and upload your own data. It is thus the VO's premier way to access public data holdings. Tables exposed through this endpoint include: main from the fai_agn schema, main from the grb_photometry schema, obscore from the ivoa schema, main from the maksutov_50_telescope schema, main from the schmidt_telescope_lc schema, data from the spectra_agn_archive schema, columns, groups, key_columns, keys, schemas, tables from the tap_schema schema.
- ID:
- ivo://CDS.VizieR/J/ApJS/222/1
- Title:
- Faint ALMA 1.2mm sources down to ~0.02mJy
- Short Name:
- J/ApJS/222/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present statistics of 133 faint 1.2mm continuum sources detected in about 120 deep Atacama Large Millimeter/submillimeter Array (ALMA) pointing data that include all the archival deep data available by 2015 June. We derive number counts of 1.2mm continuum sources down to 0.02mJy partly with the assistance of gravitational lensing, and find that the total integrated 1.2mm flux of the securely identified sources is 22.9_-5.6_^+6.7^Jy/deg2 which corresponds to 104_25_^+31^% of the extragalactic background light (EBL) measured by Cosmic Background Explorer observations. These results suggest that the major 1.2mm EBL contributors are sources with 0.02mJy, and that very faint 1.2mm sources with <~0.02mJy contribute negligibly to the EBL with the possible flattening and/or truncation of number counts in this very faint flux regime. To understand the physical origin of our faint ALMA sources, we measure the galaxy bias b_g_ by the counts-in-cells technique, and place a stringent upper limit of b_g_<3.5 that is not similar to b_g_ values of massive distant red galaxies and submillimeter galaxies but comparable to those of UV-bright, star-forming BzK galaxies (sBzKs) and Lyman break galaxies (LBGs). Moreover, in the optical and near-infrared (NIR) deep fields, we identify optical-NIR counterparts for 59% of our faint ALMA sources, the majority of which have luminosities, colors, and the IRX-{beta} relation the same as sBzKs and LBGs. We thus conclude that about a half of our faint ALMA sources are dust-poor, high-z galaxies as known as sBzKs and LBGs in optical studies, and that these faint ALMA sources are not miniature (U)LIRGs simply scaled down with the infrared brightness.
- ID:
- ivo://CDS.VizieR/II/115A
- Title:
- Faint Blue Objects at High Galactic Latitude
- Short Name:
- II/115A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data set of Faint Blue Objects at High Galactic Latitude is a catalog of objects selected according to relative ultraviolet excess from ubv three-color 1.2-m Palomar Schmidt plates. Five selected area fields centered on SA28, SA29, SA55, SA57 and SA94 are included. The data consist of color classifications, B magnitudes, 1950 equatorial coordinates and remarks; the current file contains 3678 objects. Three selected area fields were included originally, centered on SA57 (Usher 1981), SA29 (Usher, Mattson and Warnock 1982) and SA28 (Usher and Mitchell 1982). Areas centered on SA55 and SA94 were added in 1984; areas centered on SA71 (Usher et al., Paper V, 1988ApJS...66....1U) and SA82 (Usher & Mitchell, Paper VI, 1990ApJS...74..885U) were added in 2007 by CDS.
- ID:
- ivo://CDS.VizieR/J/ApJS/153/119
- Title:
- Faint blue objects at high galactic latitude
- Short Name:
- J/ApJS/153/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The US (UV-excess Starlike) survey has cataloged 3987 objects in 7 high Galactic latitude fields according to their optical colors, magnitudes, and morphologies using photographic techniques. This paper analyzes the effectiveness of the survey at producing finding lists for complete samples of hot stars and quasars that exhibit blue and/or ultraviolet excess (B-UVX) relative to the colors of halo F and G subdwarf stars. A table of 599 spectroscopic identifications summarizes the spectroscopic coverage of the US objects that has been accomplished to date.
- ID:
- ivo://CDS.VizieR/J/ApJS/49/27
- Title:
- Faint Blue Objects at High Galactic Latitude
- Short Name:
- II/115A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data set of Faint Blue Objects at High Galactic Latitude is a catalog of objects selected according to relative ultraviolet excess from ubv three-color 1.2-m Palomar Schmidt plates. Five selected area fields centered on SA28, SA29, SA55, SA57 and SA94 are included. The data consist of color classifications, B magnitudes, 1950 equatorial coordinates and remarks; the current file contains 3678 objects. Three selected area fields were included originally, centered on SA57 (Usher 1981), SA29 (Usher, Mattson and Warnock 1982) and SA28 (Usher and Mitchell 1982). Areas centered on SA55 and SA94 were added in 1984; areas centered on SA71 (Usher et al., Paper V, <A HREF="http://simbad.cds.unistra.fr/simbad/sim-ref?bibcode=1988ApJS...66....1U%201988ApJS...66....1U">1988ApJS...66....1U 1988ApJS...66....1U</A>) and SA82 (Usher & Mitchell, Paper VI, <A HREF="http://simbad.cds.unistra.fr/simbad/sim-ref?bibcode=1990ApJS...74..885U%201990ApJS...74..885U">1990ApJS...74..885U 1990ApJS...74..885U</A>) were added in 2007 by CDS.
- ID:
- ivo://CDS.VizieR/III/74
- Title:
- Faint Blue Stars near the South Galactic Pole
- Short Name:
- III/74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search for faint blue stars conducted at the Observatories of Tonantzintla and Minnesota has yielded 8746 objects which are somewhat blue. The data file is organized into three sections with the same column format. The first 1569 records are for stars with U-V of -0.4 or bluer, which are very definitely blue (Table II of the paper). The next 2929 stars are somewhat blue, with U-V values of -0.3 or -0.2 (Table III of the paper). The final 4248 records give data for stars with U-V of -0.1 or 0.0 (Table IV of the paper). Photometric, spectroscopic, and proper-motion data have later been acquired for these objects, which revealed the great variety of the objects in this catalogue: white dwarfs, subdwarfs, QSOs (quasars), compact and active galaxies. Finding charts and details about the nature of these blue objects can be found in the following papers: Haro G., and Chavira E.: 1987RMxAA..15..107H ; Chavira E.: 1988RMxAA..16..123C, Chavira E., 1990RMxAA..20...47C, and 1992RMxAA..24..139C
- ID:
- ivo://CDS.VizieR/J/other/Ap/31.714
- Title:
- Faint carbon stars in 90<l<115, |b|<5
- Short Name:
- J/other/Ap/31.71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A low dispersion spectral survey (1250{AA}/mm near H{gamma}) made with the 70-cm meniscus telescope in the region 90{deg}<=l<=115{deg}, -5{deg}<=b<=+5{deg} has led to the discovery of 267 carbon stars, 146 of which have been found for the first time. The distribution of the carbon stars in the investigated region with respect to latitude and longitude is uniform, and they have a Poisson surface distribution. The "nearest-neighbor" method shows that there is no excess of pairs of carbon stars or possible members of star clusters above their mathematical expectation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/2414
- Title:
- Faint cataclysmic variables from SDSS
- Short Name:
- J/MNRAS/421/2414
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-speed photometric observations of 20 faint cataclysmic variables (CVs) selected from the Sloan Digital Sky Survey (SDSS) and Catalina catalogues. Measurements are given of 15 new directly measured orbital periods, including four eclipsing dwarf novae (SDSS 0904+03, CSS 0826-00, CSS 1404-10 and CSS 1626-12), two new polars (CSS 0810+00 and CSS 1503-22) and two dwarf novae with superhumps in quiescence (CSS 0322+02 and CSS 0826-00). Whilst most of the dwarf novae presented here have periods below 2h, SDSS 0805+07 and SSS 0617-36 have relatively long orbital periods of 5.489 and 3.440h, respectively. The double-humped orbital modulations observed in SSS 0221-26, CSS 0345-01, CSS 1300+11 and CSS 1443-17 are typical of low-mass transfer rate dwarf novae. The white dwarf primary of SDSS 0919+08 is confirmed to have non-radial oscillations, and quasi-periodic oscillations were observed in the short-period dwarf nova CSS 1028-08 during outburst. We further report the detection of a new nova-like variable (SDSS 1519+06). The frequency distribution of orbital periods of CVs in the Catalina Real-time Transient Survey (CRTS) has a high peak near ~80min orbital period, independently confirming that found by Gansicke et al. (2009MNRAS.397.2170G) from SDSS sources. We also observe a marked correlation between the median in the orbital period distribution and the outburst class, in the sense that dwarf novae with a single observed outburst (over the 5-year baseline of the CRTS coverage) occur predominantly at shortest orbital period.
- ID:
- ivo://CDS.VizieR/J/AJ/129/2074
- Title:
- Faint Chandra sources in SWIRE
- Short Name:
- J/AJ/129/2074
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We exploit deep combined observations with Spitzer and Chandra of the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE) in the ELAIS N1 region to investigate the nature of the faint X-ray and IR sources in common, to identify active galactic nucleus (AGN)/starburst diagnostics, and to study the sources of the X-ray and IR cosmic backgrounds (XRB and CIRB).