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- ID:
- ivo://CDS.VizieR/J/PASP/124/140
- Title:
- UBVRI Hp BT and VT photonic responses
- Short Name:
- J/PASP/124/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have calculated improved photonic passbands for the UBVRI, Hipparcos Hp, and Tycho BT and VT standard systems using the extensive spectrophotometric libraries of NGSL and MILES. Using the Hp passband, we adjusted the absolute flux levels of stars in the spectrophotometric libraries so that their synthetic Hp magnitudes matched the precise Hipparcos Catalogue value. Synthetic photometry based on the renormalized fluxes was compared with the standard UBVRI, BT and VT magnitudes, and revised synthetic zero points were determined. The Hipparcos and Tycho photometry system zero points were also compared with the V-magnitude zero points of the SAAO UBVRI system, the homogenized UBV system, and the Walraven VB system.
21753. UBVRI images of Barnard 207
- ID:
- ivo://CDS.VizieR/J/A+A/605/A99
- Title:
- UBVRI images of Barnard 207
- Short Name:
- J/A+A/605/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Barnard 207 (B207, LDN 1489, LBN 777), also known as the Vulture Head nebula, is a cometary globule in the Taurus-Auriga-Perseus Molecular Cloud region. B207 is known to host a Class I protostar, IRAS 04016+2610, located at a projected distance of ~8400au from the dense core centre. Using imaging and photometry over a wide wavelength range, from UV to sub-mm, we study the physical properties of B207 and the dust grains contained within. The core density, temperature, and mass are typical of other globules found in the Milky Way interstellar medium (ISM). The increase in the dust albedo with increasing optical wavelengths, along with the detection of coreshine in the near infrared, indicates the presence of larger dust grains in B207. The measured optical, near-, mid- and far-infrared intensities are in agreement with the CMM+AMM and CMM+AMMI dust grain type of the THEMIS model, suggesting mantle formation on the dust grains throughout the globule. We investigate the possibility of turbulence being responsible for diffusing dust grains from the central core to external outer layers of B207. However, in situ formation of large dust grains cannot be excluded.
- ID:
- ivo://CDS.VizieR/J/ApJS/193/1
- Title:
- UBVRIJHK color-temperature calibration
- Short Name:
- J/ApJS/193/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A collection of Johnson/Cousins photometry for stars with known [Fe/H] is used to generate color-color relations that include the abundance dependence. Literature temperature and bolometric correction (BC) dependences are attached to the color relations. The JHK colors are transformed to the Bessell & Brett (1988PASP..100.1134B) homogenized system. The main result of this work is the tabulation of seven colors and the V-band BC as a function of Teff, logg, and [Fe/H] for -1.06<V-K<10.2 and an accompanying interpolation program. Improvements to the present calibration would involve filling photometry gaps, obtaining more accurate and on-system photometry, knowing better logg and [Fe/H] values, improving the statistics for data-impoverished groups of stars such as metal-poor K dwarfs, applying small tweaks in the processing pipeline, and obtaining better empirical temperature and BC relations, especially for supergiants and M stars. A way to estimate dust extinction from M dwarf colors is pointed out.
- ID:
- ivo://CDS.VizieR/J/ApJS/101/117
- Title:
- UBVRIJHKLMNQ photometry in Taurus-Auriga
- Short Name:
- J/ApJS/101/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper analyzes optical and infrared photometry of pre-main- sequence stars in the Taurus-Auriga molecular cloud. More than half of the stars in our sample have excess near-infrared emission. The near-infrared excesses correlate very well with other measures of activity, such as Halpha emission, ultraviolet excess emission, millimeter continuum emission, and the presence of reflection nebulae and molecular outflows. The infrared colors and the ratio of far-infrared to bolometric luminosity display a smooth progression from the most deeply embedded protostars to optically visible T Tauri stars. Infalling envelope models account for the colors of protostars; simple disk models similarly reproduce the colors of many T Tauri stars. Both the stellar birth line and a 10^5yr isochrone provide a reasonable upper envelope to the luminosity distribution of optically visible stars in the H-R diagram. Only a few stars in the cloud have apparent ages exceeding 2-3x10^6yr, as derived from detailed stellar evolution calculations. The distribution of stars in the H-R diagram indicates that the cloud has formed stars at a roughly constant rate for the past 1-2x10^6yr. Analyses of the J- and K-luminosity functions support this conclusion. Within the uncertainties, the observed mass distribution for optically visible stars agrees with a Miller-Scalo initial mass function. Source statistics imply a lifetime of 1-2x10^5yr for the typical protostar in Taurus-Auriga. There is no evidence, however, that these sources lie on the stellar birth line. Indeed, the protostellar luminosity function is essentially identical to the luminosity function derived for optically visible T Tauri stars in the cloud. These results provide some support for the evolutionary sequence -- embedded protostar -> T Tauri star with a circumstellar disk -> T Tauri star without a circumstellar disk -- currently envisioned in standard models of low-mass star formation. Source statistics and infrared color-color diagrams demonstrate that pre-main-sequence stars develop bluer colors and display less evidence for circumstellar material with time. The data show little evidence, however, for the luminosity evolution expected along the proposed evolutionary sequence. Time-dependent accretion during the infall phase may account for the low luminosity of Taurus-Auriga protostars; this hypothesis requires more tests.
- ID:
- ivo://CDS.VizieR/J/A+AS/93/383
- Title:
- UBVRIJHKL photometry of symbiotic stars
- Short Name:
- J/A+AS/93/383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/508/371
- Title:
- UBVRIJHK observations of SN 2007gr
- Short Name:
- J/A+A/508/371
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric and spectroscopic observations at optical and near-infrared wavelengths of the nearby type-Ic supernova 2007gr. These represent the most extensive data-set to date of any supernova of this sub-type, with frequent coverage from shortly after discovery to more than one year post-explosion.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/2530
- Title:
- UBVRIJHK photometry in NGC1624
- Short Name:
- J/MNRAS/411/2530
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive multiwavelength analysis of the young cluster NGC 1624 associated with the HII region Sh2-212 using optical UBVRI photometry, optical spectroscopy and GMRT radio continuum mapping along with the near-infrared (NIR) JHK archival data.
- ID:
- ivo://CDS.VizieR/J/AJ/122/2055
- Title:
- UBVRIJHK photometry of AGN field stars
- Short Name:
- J/AJ/122/2055
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a total of 12,436 photometric measures of 371 field stars of 26 quasars in the visible (UBVRI) and 22,276 photometric measures of 122 field stars of 13 quasars in the near-infrared (JHK), giving a total of 34,712 measures. Of these, 115 stars in 12 fields are calibrated in both ranges. One further field, Mrk 421, was calibrated, but on close examination all sources were found to be probably nonstellar; thus these results are not included here. The stars observed cover the range from V=11 to V=20 and from K=9 to K=17 and are well distributed around the sky north of declination -30{deg}. This represents the initial sample of an extensive catalog of calibrated fields that will cover the northern sky down to declination -30{deg} and that will cover a wide range of Galactic latitudes. These fields will be useful both for photometry of AGNs in the range from B to K and also as faint calibration standards for large telescopes. The median absolute total error on the photometry, including all known error sources, ranges from 0.008mag in J to 0.034mag in B. These errors will be greatly reduced with the addition of further data in the future, although the final precision is fundamentally limited by the photometric errors in the existing lists of calibration stars used to calibrate these data.
- ID:
- ivo://CDS.VizieR/J/A+A/509/A104
- Title:
- UBVRIJHK photometry of Dolidze 25
- Short Name:
- J/A+A/509/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The analysis of our deep UBVRIJHK photometry of Dolidze 25, located in the central area of the HII region Sh 2-284, reveals a young cluster with coeval MS and PMS populations of age 3.2-5Myr. The mass function for the optical PMS population in the mass range above 1.3-3.5M_{sun}_ is well fitted by a Salpeter mass function. On the other hand, the NIR photometry results indicate a large number of sources with H-Ks excess, practically distinct from the optical PMS candidate members. In addition, a distinctly older cluster member population of age 40Myr is suggested. The distance determined for the cluster from quantitative fits to ZAMS and isochrones (3.6kpc) is distinctly lower than previously published values. This result originates in the consistent use of low metallicity models for ZAMS fitting, applying published metallicity values for the cluster
