Photometric and Spectroscopic Studies of Early-Type Stars Between Galactic Longitude L = 338° and L = 33°.

Hiltner, W. A.; Iriarte, B.

doi:10.1086/146068

Cited by 18 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A.18 and A.19 we present LiLiMaRlin spectra for three of the same six O-type systems. Five of the O-type systems had not appeared in GOSSS or LiLiMaRlin before but all had prior classifications as O-type: BD −13 4930 (O9.7 V here, O9.5 V in Hiltner & Iriarte (1955)), BD −13 4929 (an interesting SB3 system with a classification of O8 V + B0.5: V + B0.5: V previously identified and similarly classified by Sana et al 2009), BD −13 4928 (O9.7 IVnn here, O9.5 Vn in Hillenbrand et al (1993)), ALS 4903 (O9 V here, O8.5 V in Hillenbrand et al (1993)), and ALS 15 352 (O8 IV here, O8.5 V in Hillenbrand et al 1993). The sixth O star is ALS 15 360, classified as O7 V((f))z in Maíz Apellániz et al ( 2016) and here (with a better S/N spectrogram) as O6.5 V((f))z.…”

Section: Villafrancamentioning

confidence: 99%

The Villafranca catalog of Galactic OB groups

Apellániz

Barbá

Aranda

et al. 2022

A&A

View full text Add to dashboard Cite

Context. This is the second paper of a series on Galactic OB groups that uses astrometric and photometric data from Gaia and spectral classifications from the Galactic O-Star Spectroscopic Survey (GOSSS) and the Library of Libraries of Massive-star high-Resolution spectra (LiLiMaRlin). The previous paper was based on the second Gaia data release (DR2). Since then, the early third Gaia data release (EDR3) has appeared with new astrometry and photometry. Aims. The two aims of this paper are to revise the results for the sample from paper I using Gaia EDR3 data and to expand the sample of analyzed stellar groups to 26, from Villafranca O-001 to Villafranca O-026. Methods. We used GOSSS to select Galactic stellar groups with O stars and an updated version of the method in paper 0 of this series, combining Gaia EDR3 G + G BP + G RP photometry, positions, proper motions, and parallaxes to assign memberships and measure distances. We present 99 spectra from GOSSS and 32 from LiLiMaRlin for stars in the analyzed groups or in their foreground.Results. We derived distances to the 26 stellar groups with unprecedented precision and accuracy, with total (random plus systematic) uncertainties lower than 1% for distances within 1 kpc and of ∼3% around 3 kpc, which are values almost four times better than for Gaia DR2. We provide homogeneous spectral types for 110 stars and correct a number of errors in the literature, especially for objects in Villafranca O-023 (Orion nebula cluster). For each group, we discuss its membership and present possible runaway and walkaway stars. At least two of the studied groups, Villafranca O-O12 S in NGC 2467 and Villafranca O-014 NW in the North America nebula, are orphan clusters in which the most massive stars have been ejected by dynamical interactions, leaving objects with a capped mass function. The existence of such clusters has important consequences for the study of the initial mass function (IMF), the distribution of supernova explosions across the Galaxy, and the population and dynamics of isolated compact objects. We fit pre-main-sequence (PMS) isochrones to the color-magnitude diagrams (CMDs) of four clusters to derive ages of 2.0±0.5 Ma for Villafranca O-026 (σ Orionis cluster), 4±2 Ma for Villafranca O-016 (NGC 2264), 5.0±0.5 Ma for Villafranca O-021 (NGC 2362), and 8±2 Ma for Villafranca O-024 (γ Velorum cluster).

show abstract

Section: Villafrancamentioning

confidence: 99%

The Villafranca catalog of Galactic OB groups

Apellániz

Barbá

Aranda

et al. 2022

A&A

View full text Add to dashboard Cite

show abstract

“…For HD 24 912, however, we adopt a luminosity class I instead of III as assigned by Walborn, in agreement with Herrero et al (1992) who found that even with the correction for the effects of centrifugal forces the gravity of this star is much lower than for typical luminosity class III objects. For the two stars without a classification by Walborn, BD+56739 and HD 338 926, spectral types and luminosity classes originate from Hiltner (1956) and from Hiltner & Iriarte (1955), respectively.…”

Section: Sample Starsmentioning

confidence: 99%

Bright OB stars in the Galaxy

Маркова

Puls

Repolust

et al. 2003

A&A

118

201

View full text Add to dashboard Cite

Abstract. We study mass-loss and wind momentum rates of 29 Galactic O-type stars with luminosity classes I, III and V by means of a pure Hα profile analysis and investigate to what extent the results compare to those originating from a state-ofthe-art, complete spectral analysis. Our investigation relies on the approximate method developed by Puls et al. (1996) which we have modified to account for the effects of line-blanketing. Effective temperatures and gravities needed to obtain quantitative results from such a simplified approach have been derived by means of calibrations based on most recent spectroscopic NLTE analyses and models of Galactic stars by Repolust et al. (2003) and Martins et al. (2002). Comparing (i) the derived winddensities to those determined by Repolust et al. (2003) for eleven stars in common and (ii) the Wind-momentum Luminosity Relationship (WLR) for our sample stars to those derived by other investigations, we conclude that our approximate approach is actually able to provide consistent results. Additionally, we studied the consequences of "fine tuning" some of the direct and indirect parameters entering the WLR, especially by accounting for different possible values of stellar reddening and distances. Combining our data set with the corresponding data provided by Herrero et al. (2002) and Repolust et al. (2003) we finally study the WLR for the largest sample of Galactic O-type stars gathered so far, including an elaborate error treatment. The established disagreement between the theoretical predictions and the "observed" WLRs being a function of luminosity class is suggested to be a result of wind clumping. Different strategies to check this hypothesis are discussed, particularly by comparing the Hα mass-loss rates with the ones derived from radio observations.

show abstract

“…Follow-up low-resolution spectroscopy obtained by Hiltner & Iriarte (1955) resulted in the spectral type A3: ia, while Stephenson & Sanduleak (1971) listed it as B9 ia. The UBV observations by Hiltner & Iriarte (1955) and Kozok (1985a), quoted in Table 1, revealed that the star is heavily reddened and that the spectral type, which can be derived from the photometry, is B9 ± 1. On the basis of the MK classification (A3 ia), Humphreys (1970) estimated its distance from the Sun as 9.6 kpc, while Kozok (1985b) derived a value of 1.2 kpc from the color-indices analysis.…”

Section: Introductionmentioning

confidence: 99%

AS 314: A dusty A–type hypergiant

Мирошниченко

Ченцов

Клочкова

2000

Astron. Astrophys. Suppl. Ser.

View full text Add to dashboard Cite

Abstract. We present the results of our observations of the poorly-studied emission-line star AS 314 which include high-resolution spectroscopy, obtained at the 6 -meter telescope of the Russian Academy of Sciences, multicolor optical and near-infrared photometry. The strong Hα line, Hβ and Hγ of moderate strength and a number of weak Fe ii lines were detected in emission. The Balmer lines and most of the Fe ii lines show narrow P Cyg-type profiles which implies a very low terminal velocity of the stellar wind. Very weak signs of emission are found in Hδ. Photospheric lines detected for the first time allowed us to determine the object's spectral type, A0. The luminosity, M bol ∼ −8.0 mag was estimated using several methods and implies that AS 314 is a hypergiant, which is located at about 10 kpc from the Sun and has an initial mass of ∼ 20 M . Modeling of the Balmer line profiles resulted in the following parameters of the stellar wind:The star is located within the LBV strip in the HRD. Its noticeable far-IR excess is due to the circumstellar dust emission and is likely evidence of an LBV-type outburst in the past.

show abstract

Photometric and Spectroscopic Studies of Early-Type Stars Between Galactic Longitude L = 338° and L = 33°.

Cited by 18 publications

References 0 publications

The Villafranca catalog of Galactic OB groups

The Villafranca catalog of Galactic OB groups

Bright OB stars in the Galaxy

AS 314: A dusty A–type hypergiant

Contact Info

Product

Resources

About