- ID:
- ivo://CDS.VizieR/II/82
- Title:
- Galactic O-type Stars
- Short Name:
- II/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation from the literature of all O-type stars for which spectral types, luminosity classes, and UBV photometry exist. The catalog contains 765 stars, for each of which designation (HD, DM, etc.), spectral type, V, B-V, absolute visual magnitude, absolute bolometric magnitude, cluster membership, distance, galactic coordinates, and source references are given. In addition, the authors have included derived values of absolute visual and bolometric magnitudes, and distances. The Catalog of Galactic O-Type Stars (Garmany, Conti and Chiosi 1982) is a compilation from the literature of all O-type stars for which spectral types, luminosity classes and UBV photometry exist. Most of the entries come from Cruz-Gonzalez, et al. (1974) and Humphreys (1978), with additional stars from Garrison and Kormendy (1976), Garrison, Hiltner and Schild (1977), Garrison and Schild (1979), Feinstein, Marraco and Muzzio (1973), Feinstein, Marraco and Forte (1976), and Moffat, FitzGerald and Jackson (1979).
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- ID:
- ivo://CDS.VizieR/J/ApJS/253/54
- Title:
- Galactic O-type stars from LAMOST spectra
- Short Name:
- J/ApJS/253/54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper reports 209 O-type stars found with LAMOST. All 135 new O-type stars discovered so far with LAMOST are given. Among them, 94 stars are first presented in this sample. There are 1 Iafpe star, 5 Onfp stars, 12 Oe stars, 1 Ofc stars, 3 ON stars, 16 double-lined spectroscopic binaries, and 33 single-lined spectroscopic binaries. All O-type stars are determined based on LAMOST low-resolution spectra (R~1800), with their LAMOST median-resolution spectra (R~7500) as supplements.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/4
- Title:
- GOSSS III. 142 additional O-type systems
- Short Name:
- J/ApJS/224/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R~2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A77
- Title:
- H{alpha} images of HD93521
- Short Name:
- J/A+A/546/A77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Owing to its unusual location and its isolation, the nature of the high Galactic latitude O9.5 Vp object HD 93521 is still uncertain. We have collected X-ray and optical observations to characterize the star and its surroundings.
- ID:
- ivo://CDS.VizieR/J/A+A/428/149
- Title:
- Hipparcos parallaxes of O stars
- Short Name:
- J/A+A/428/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the absolute visual magnitude of the majority of bright O stars in the sky as predicted from their spectral type with the absolute magnitude calculated from their apparent magnitude and the Hipparcos parallax. We find that many stars appear to be much fainter than expected, up to five magnitudes. We find no evidence for a correlation between magnitude differences and the stellar rotational velocity as suggested for OB stars by Lamers et al. (1997A&A...325L..25L), whose small sample of stars is partly included in ours.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A115
- Title:
- HST Hot Star Library
- Short Name:
- J/A+A/615/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Libraries of stellar spectra find many uses in astrophysics, from photometric calibration to stellar population synthesis. We present low resolution spectra of 40 stars from 0.2 micrometers (ultraviolet) to 1.0 micrometers (near infrared) with excellent fluxing. The stars include normal O-type stars, helium-burning stars, and post-asymptotic giant branch (PAGB) stars. Spectra were obtained with the Space Telescope Imaging Spectrograph (STIS) installed in the Hubble Space Telescope (HST) using three low resolution gratings, G230LB, G430L, and G750L. Cosmic ray hits and fringing in the red were corrected. A correction for scattered light was applied, significant only for our coolest stars. Cross-correlation was used to bring the spectra to a common, final, zero velocity wavelength scale. Finally, synthetic stellar spectra were used to estimate line of sight dust extinction to each star, and a five-parameter dust extinction model was fit, or a one-parameter fit in the case of low extinction. These spectra dovetail with the similar Next Generation Stellar Library (NGSL) spectra, extending the NGSL's coverage of stellar parameters, and extending to helium burning stars and stars that do not fuse. The fitted dust extinction model showed considerable variation from star to star, indicating variations in dust properties for different lines of sight. Interstellar absorption lines are present in most stars, notably MgII.
- ID:
- ivo://CDS.VizieR/J/A+A/410/905
- Title:
- Interstellar reddening parameter measurements
- Short Name:
- J/A+A/410/905
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new measurements of the interstellar reddening parameter R_V_=A_V_/E(B-V) towards 185 O stars, using J, H, Ks photometry from the 2MASS project. The average R_V_ from these is of 3.19+/-0.50. All objects whose R_V_ departs from this value by more than 2 sigma have been recognized. Ten objects have R_V_ higher than this value and two lower. In the Cygnus region R_V_ values follow the behaviour of the general interstellar medium, while in the Carina arm, in spite of the relatively larger distance, local cloud effects prevail. The relatively few stars of our sample whose Hipparcos parallaxes are reliable, are found to have distances systematically smaller than the distances derived by the spectroscopic parallaxes. We argue that this effect is consistent with the recently claimed discovery of grey extinction towards OB stars.
- ID:
- ivo://CDS.VizieR/III/115
- Title:
- IUE Atlas of O-Type Stellar Spectra
- Short Name:
- III/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The International Ultraviolet Explorer Atlas of O-Type Spectra From 1200 to 1900 A (Walborn et el. 1985) lists normalized fluxes and flux quality factors, splice points, and identifying information (star name/number, spectral type, SWP number, and name of the principal investigator) on 101 spectrograms of 98 O-type stars. The primary purpose of this work is to investigate the existence of systematic trends in the ultraviolet line spectra of the O stars, including the prominent stellar wind features, and the degree to which they correlate with the optical spectral classifications. A subsidiary objective is to identify ultraviolet features which may themselves prove useful as classifications criteria.
- ID:
- ivo://CDS.VizieR/J/PAZh/32/866
- Title:
- JHKLM photometry for 22 hot stars
- Short Name:
- J/PAZh/32/866
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the JHKLM photometry for 22 hot stars, 11 of which were identified in the GCVS. For all of the observed objects, we have estimated the interstellar reddening, angular diameters, and the volume emission measures of their gaseous shalls.
- ID:
- ivo://CDS.VizieR/J/ApJ/748/96
- Title:
- Massive binaries in the LMC
- Short Name:
- J/ApJ/748/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The stellar mass-luminosity relation is poorly constrained by observations for high-mass stars. We describe our program to find eclipsing massive binaries in the Magellanic Clouds using photometry of regions rich in massive stars, and our spectroscopic follow-up to obtain radial velocities and orbits. Our photometric campaign identified 48 early-type periodic variables, of which only 15 (31%) were found as part of the microlensing surveys. Spectroscopy is now complete for 17 of these systems, and in this paper we present analysis of the first two, LMC 172231 and ST2-28, simple detached systems of late-type O dwarfs of relatively modest masses. Our orbit analysis yields very precise masses (~2%), and we use tomography to separate the components and determine effective temperatures by model fitting, necessary for determining accurate (0.05-0.07 dex) bolometric luminosities in combination with the light-curve analysis. Our approach allows more precise comparisons with evolutionary theory than previously possible. To our considerable surprise, we find a small, but significant, systematic discrepancy: all of the stars are slightly undermassive, by typically 11% (or overluminous by 0.2 dex) compared with that predicted by the evolutionary models. We examine our approach for systematic problems, but find no satisfactory explanation. The discrepancy is in the same sense as the long-discussed and elusive discrepancy between the masses measured from stellar atmosphere analysis with the stellar evolutionary models, and might suggest that either increased rotation or convective overshooting is needed in the models.
