- ID:
- ivo://CDS.VizieR/III/106
- Title:
- MK Classification of Visual Multiples
- Short Name:
- III/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectral types listed here represent about one-third of a program of MK classification of all the Northern (Dec>-30deg) visual components brighter than B~8.0mag. The spectra used were obtained in 1969-1980 with the Cassegrain spectrograph attached to the Kitt Peak No.2 91-cm telescope. The grating spectra have a dispersion of 128{AA}/mm, and are 1.2mm wide; they are overexposed and underdeveloped to minimize grain. The spectra were classified against standards of the "Revised MK Spectral Atlas for stars earlier than the Sun" by Morgan, Abt and Tapscott (Yerkes Obs. 1978) and of the "Spectral classification" of Morgan and Keenan (1973ARA&A..11...29M). Accurate positions, V magnitudes rounded to 0.1 mag, and remarks were added by B. Skiff in June 2004 as the file "more.dat"; some typos in the catalog were also corrected (see the "History" section below).
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Search Results
- ID:
- ivo://CDS.VizieR/III/117
- Title:
- MK Classifications of Close Visual Binaries
- Short Name:
- III/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Each component of 170 close visual binaries has been classified with new procedures for controlling contamination problems. These classifications are shown to be on the MK system. Two sources of area scanner UBV photometry were compared in order to establish homogeneous photometric as well as spectroscopic data. From a consideration of systematic errors in the V magnitude difference between components the photometry of Hurly and Warner is to be preferred. Absolute magnitudes for each binary are derived from magnitude difference via a tested MK-Mv map.
- ID:
- ivo://CDS.VizieR/J/ApJS/180/117
- Title:
- MK classifications of spectroscopic binaries
- Short Name:
- J/ApJS/180/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New MK spectral classifications are given for 145 spectroscopic binaries (SBs) with A-F primaries because two-dimensional types are lacking for more than one-third of the A-F SBs with known orbital elements in the current catalog. Compared with the classifications by Morgan, Keenan, and their students, the new classifications give types that are 1.1+/-0.2 subclasses later and 0.7+/-0.1 luminosity classes fainter. Also listed are selected published MK types from Brian Skiff's recent compilation (Cat. <B/mk>).
- ID:
- ivo://CDS.VizieR/III/149
- Title:
- MK Standard Stars
- Short Name:
- III/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The purpose of the present work is to provide a complete list of MK standard stars, selected from the main papers related to this subject, according to the recommendations of both authors of the MK system. The catalogue provides a list of 963 standard stars, with their spectral type, luminosity, equatorial coordinates, magnitudes, colour index (B-V), and references. The magnitude and colours were taken from Mermillod (1986) UBV Photoelectric Photometry Catalogue (catalog <II/122>). In the cases without observations with the UBV catalogue, the apparent magnitude was taken from the SIMBAD data-base (SIMBAD is described at <http://cdsweb.u-strasbg.fr/Simbad.html>)
- ID:
- ivo://CDS.VizieR/V/69
- Title:
- MK, UBV Time and Latitude Stars
- Short Name:
- V/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- MK spectral classifications are given for 591 stars which are used for time and latitude observations at Mizusawa and Washington. The classifications in the MK system were made by slit spectrograms of dispersion 73 A/mm at H-gamma which were taken with the 91cm reflector at the Okayama Astrophysical Observatory. Photometric observations in UBV were made with the 1-meter reflector at the Flagstaff Station of U.S. Naval Observatory.
- ID:
- ivo://CDS.VizieR/J/other/KFNT/12.20
- Title:
- Nearby stars metallicities
- Short Name:
- J/other/KFNT/12.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue for nearby stars' metallicities has been compiled. The catalogue contains 558 values obtained from photometric UBV data
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2737
- Title:
- New PMS K/M Stars in Upper Scorpius
- Short Name:
- J/MNRAS/448/2737
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 237 new spectroscopically confirmed pre-main-sequence K- and M-type stars in the young Upper Scorpius subgroup of the Sco-Cen association, the nearest region of recent massive star formation. Using the Wide-Field Spectrograph at the Australian National University 2.3 m telescope at Siding Spring, we observed 397 kinematically and photometrically selected candidate members of Upper Scorpius, and identified new members by the presence of lithium absorption. The HR-diagram of the new members shows a spread of ages, ranging from ~3 to 20Myr, which broadly agrees with the current age estimates of ~5-10Myr. We find a significant range of Li 6708 equivalent widths among the members, and a minor dependence of HR-diagram position on the measured equivalent width of the Li 6708{AA} line, with members that appear younger having more lithium. This could indicate the presence of either populations of different age, or a spread of ages in Upper Scorpius. We also use Wide-Field Infrared Survey Explorer data to infer circumstellar disc presence in 25 of the members on the basis of infrared excesses, including two candidate transition discs. We find that 11.2+/-3.4% the M0-M2 spectral type (0.4-0.8M_{sun}_) Upper Sco stars display an excess that indicates the presence of a gaseous disc.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A31
- Title:
- New spectral classification for hot subdwarfs
- Short Name:
- J/A+A/551/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An MK (Morgan-Keenan)-like system of spectral classification for hot subdwarfs is presented. We find that a three-dimensional spectral type, consisting of a 'spectral' class, a 'luminosity' class, and a 'helium' class, is necessary to classify the sdO (subdwarf O) and sdB (subdwarf B) stars. In addition, the helium-strong stars appear to form two parallel spectral sequences: one showing strong lines of CII, CIII, or CIV, and the other with these same lines weak or absent. We also give a preliminary calibration of the new spectral types in terms of effective temperature, surface gravity, and surface helium-to-hydrogen abundance ratio, and show the relation between the new spectral types and the natural groups defined by the PG (Palomar-Green) survey.
- ID:
- ivo://CDS.VizieR/J/PAZh/34/21
- Title:
- New spectral types for Tycho2 stars
- Short Name:
- J/PAZh/34/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the spectroscopic and trigonometric parallaxes of common stars from the Tycho-2 Spectral Type and Hipparcos Catalogues. This comparison has revealed that the distance estimations for the overwhelming majority of stars by both methods yield very similar results. However, there is a small fraction of stars for which the distance estimates differences.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A3
- Title:
- New survey of supergiants in the MCs
- Short Name:
- J/A+A/578/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this study, we conduct a pilot program aimed at the red supergiant population of the Magellanic Clouds. We intend to extend the current known sample to the unexplored low end of the brightness distribution of these stars, building a more representative dataset with which to extrapolate their behaviour to other Galactic and extra-galactic environments. We select candidates using only near infrared photometry, and with medium resolution multi-object spectroscopy, we perform spectral classification and derive their line-of-sight velocities, confirming the nature of the candidates and their membership to the clouds. Around two hundred new RSGs have been detected, hinting at a yet to be observed large population. Using near and mid infrared photometry we study the brightness distribution of these stars, the onset of mass-loss and the effect of dust in their atmospheres. Based on this sample, new a priori classification criteria are investigated, combining mid and near infrared photometry to improve the observational efficiency of similar programs as this.
