- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1767
- Title:
- Gaia spectrophotometric standard stars I.
- Short Name:
- J/MNRAS/426/1767
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe two ground-based observing campaigns aimed at building a grid of approximately 200 spectrophotometric standard stars (SPSS), with an internal =~1% precision and tied to Vega within =~3%, for the absolute flux calibration of data gathered by Gaia, the European Space Agency (ESA) astrometric mission. The criteria for the selection and a list of candidates are presented, together with a description of the survey strategy and the adopted data analysis methods. We also discuss a short list of notable rejected SPSS candidates and difficult cases, based on identification problems, literature discordant data, visual companions and variability. In fact, all candidates are also monitored for constancy (within +/-5mmag, approximately). In particular, we report on a CALSPEC standard, 1740346, that we found to be a {delta} Scuti variable during our short-term monitoring (1-2h) campaign.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/3616
- Title:
- Gaia SPSS variability monitoring
- Short Name:
- J/MNRAS/462/3616
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the short-term constancy monitoring of candidate Gaia Spectrophotometric Standard Stars (SPSS). We obtained time series of typically 1.24 hour - with sampling periods from 1-3 min to a few hours, depending on the case - to monitor the constancy of our candidate SPSS down to 10mmag, as required for the calibration of Gaia photometric data. We monitored 162 out of a total of 212 SPSS candidates. The observing campaign started in 2006 and finished in 2015, using 143 observing nights on nine different instruments covering both hemispheres. Using differential photometry techniques, we built light curves with a typical precision of 4 mmag, depending on the data quality. As a result of our constancy assessment, 150 SPSS candidates were validated against short term variability, and only 12 were rejected because of variability including some widely used flux standards such as BD+174708, SA 105-448, 1740346, and HD 37725.
- ID:
- ivo://CDS.VizieR/J/ApJ/508/397
- Title:
- H-band Spectral Standards
- Short Name:
- J/ApJ/508/397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of H-band spectra for 85 stars of approximately solar abundance observed at a resolving power of 3000 with the KPNO Mayall 4m Fourier Transform Spectrometer. The atlas covers spectral types O7-M5 and luminosity classes I-V as defined on the MK system. The final reduced spectra are available in addition to data products used in the analysis of the paper such as Tables of equivalent width measurements for spectral features of interest in deriving effective temperatures and estimating luminosity classes of stars. The final spectra cover wavelength range 1.52 to 1.79 microns.
- ID:
- ivo://CDS.VizieR/II/300
- Title:
- JMMC Stellar Diameters Catalogue - JSDC
- Short Name:
- II/300
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains stellar angular diameter estimate for bright stars, complete for all stars with Hipparcos parallaxes. The JMMC Calibrator Workgroup has long developed methods to estimate the angular diameter of stars, and provides this expertise in the SearchCal software (http://www.jmmc.fr/searchcal). "SearchCal" creates a dynamical catalogue of stars suitable to calibrate Optical Long-Baseline Interferometry (OLBI) observations from on-line queries of CDS catalogues, according to observational parameters. In essence, SearchCal is limited only by the completeness of the stellar catalogues it uses, and in particular is not limited in magnitude. SearchCal being an application centered on OLBI peculiar purposes, it appeared useful to publish the estimated angular diameters of all stars with known parallaxes in a static catalogue. The present catalogue of stellar angular diameters has been obtained from an automated SearchCal results aggregation on the whole celestial sphere. For each star, the value of the limb-darkened angular diameters are computed using a surface brightness method and calibrations for (B-V), (V-R) and (V-K) color indexes. Stars whose angular diameters estimated from the various color indexes are not comparable, are rejected, and a reliable error on the estimated diameter is computed (1). For details of the method see Bonneau et al. (2006A&A...456..789B). To avoid specific confusion problems, spectroscopic binaries in the 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix et al., 2009, Cat. B/sb9) or close visual binaries with a separation of less than 2 arc seconds in the Washington Visual Double Star Catalog (Mason et al., 2001, Cat. B/wds) have been filtered out.
- ID:
- ivo://CDS.VizieR/II/346
- Title:
- JMMC Stellar Diameters Catalogue - JSDC. Version 2
- Short Name:
- II/346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains stellar angular diameter estimates for nearly all the stars of the Hipparcos and Tycho catalogue that have an associated spectral type in Simbad/CDS. The median error on the diameters is around 1.5%, with possible biases of around ~2%. For each object, the limb-darkened diameter retained is the mean value of several estimates performed using different couples of photometries. The chi-square representing the dispersion between these values is also given (it is below 2 for ~400000 stars). An additional flag signals stars that could represent a risk if chosen as calibrators for Optical Long-Baseline Interferometry, independently of the correctness of their apparent diameter estimate. This catalog replaces the catalog II/300/jsdc .
- ID:
- ivo://CDS.VizieR/J/ApJ/783/131
- Title:
- Kinematic of stars in Galactic center
- Short Name:
- J/ApJ/783/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new kinematic measurements and modeling of a sample of 116 young stars in the central parsec of the Galaxy in order to investigate the properties of the young stellar disk. The measurements were derived from a combination of speckle and laser guide star adaptive optics imaging and integral field spectroscopy from the Keck telescopes. Compared to earlier disk studies, the most important kinematic measurement improvement is in the precision of the accelerations in the plane of the sky, which have a factor of six smaller uncertainties ({sigma}~10{mu}as/yr2). We have also added the first radial velocity measurements for eight young stars, increasing the sample at the largest radii (6''-12'') by 25%. We derive the ensemble properties of the observed stars using Monte Carlo simulations of mock data. There is one highly significant kinematic feature (~20{sigma}), corresponding to the well-known clockwise disk, and no significant feature is detected at the location of the previously claimed counterclockwise disk. The true disk fraction is estimated to be ~20%, a factor of ~2.5 lower than previous claims, suggesting that we may be observing the remnant of what used to be a more densely populated stellar disk. The similarity in the kinematic properties of the B stars and the O/WR stars suggests a common star formation event. The intrinsic eccentricity distribution of the disk stars is unimodal, with an average value of <e> =0.27+/-0.07, which we show can be achieved through dynamical relaxation in an initially circular disk with a moderately top-heavy mass function.
- ID:
- ivo://CDS.VizieR/J/AJ/133/768
- Title:
- KPNO's UBVRI filter transmission characteristics
- Short Name:
- J/AJ/133/768
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric data on the Johnson-Kron-Cousins UBVRI broadband photometric system are provided for a set of stars that have been used as spectrophotometric standard stars for the Hubble Space Telescope.
- ID:
- ivo://CDS.VizieR/I/335
- Title:
- LUT Survey Catalogue Data Release 1
- Short Name:
- I/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an near-ultraviolet star catalogue extracted from the Lunar-based Ultraviolet Telescope (LUT) survey program. LUT's observable sky area is a circular belt around the Moon's north pole, and the survey program covers a preferred area for about 2400 square degrees which includes a region of the Galactic plane. All the sources have signal-to-noise ratio larger than 5, and the corresponding magnitude limit is typically 14.4mag, which can be deeper as ~16 mag if the stray light contamination is in the lowest level. A total number of 86,467 stars are recorded in the catalogue.
- ID:
- ivo://CDS.VizieR/J/MNRAS/372/1804
- Title:
- Magnetic fields of chem. peculiar stars
- Short Name:
- J/MNRAS/372/1804
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectropolarimetric observations of 96 chemically peculiar (CP) main-sequence stars have been carried out at the 6-m telescope at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) with the aim of searching for the presence of stellar magnetic fields. The stars selected for investigation were CP stars known to have strong anomalies in the wavelength region of the continuum flux depression around {lambda} 5200{AA}. This selection was conducted with the aid of low-resolution spectral observations, made with the SAO RAS 1-m telescope, and of published differential photometric data. Magnetic fields have been successfully detected in 72 stars of which only three stars were previously known to have magnetic fields. For two stars, the longitudinal component of the magnetic field B_e_exceeds 5kG: HD178892 - 7.4kG, and HD258686 - 6.7kG. We failed to reliably detect the magnetic field in the other 24 CP stars. These stars are mostly fast rotators, a feature which hampers accurate measurements of B_e_. It is demonstrated in this paper that selecting candidate magnetic stars by considering their photometric indices Z or {Delta}alpha}, or alternatively, by inspecting low-resolution spectra around the {lambda}5200{AA} flux depression, considerably increases the detection rate.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/75.294
- Title:
- Magnetic fields of CP stars (2012)
- Short Name:
- J/other/AstBu/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of measuring longitudinal magnetic fields (Be), rotation velocities (v_esini), and radial velocities (VR) of 163 stars observed with the Main Stellar Spectrograph (MSS) of the 6-m BTA telescope of the Special Astrophysical Observatory in 2012. Observations of standard stars without magnetic fields confirm the absence of systematic errors capable of introducing distortions into the longitudinal-field measurement results.
