- ID:
- ivo://CDS.VizieR/III/180
- Title:
- SS(77) Catalogue: new H-alpha em* in Milky Way
- Short Name:
- III/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data on 455 H-{alpha} emission stars found in all parts of the Milky Way, virtually all previously unpublished, are tabulated, with newly measured coordinates usually accurate to better than 2". A half-dozen stars appear to have been published previously with erroneous coordinates, or to have been published but omitted from the general catalog by Wackerling (1970MmRAS..73..153W). Included among the new stars are known OB stars of the Luminous Stars in the Northern Milky Way survey, from the Hamburg zones, which were originally searched for H{alpha} emission at slightly lower spectral resolution than we have used. The stars are in general of early spectral type, and are mostly fainter than the limits of the DM catalogs. The objective-prism plates covered the entire Milky Way within about 10deg of the galactic equator, at a spectral dispersion of about 1000{AA}/mm at H-alpha.
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Search Results
- ID:
- ivo://CDS.VizieR/III/120
- Title:
- Stars with CaII H and K emission
- Short Name:
- III/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Intensities and widths of emission cores of H and K lines from the literature are presented for over 1400 stars of spectral types F, G, K and M.
- ID:
- ivo://CDS.VizieR/J/A+A/402/963
- Title:
- Stephenson H{alpha} stars
- Short Name:
- J/A+A/402/963
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of spectroscopic observations for 52 objects from the list of H{alpha} emission stars of Stephenson (1986ApJ...300..779S). Out of six known T Tauri stars observed, five showed H{alpha} in emission and in one (StHa 40), H{alpha} changed from being in absorption to emission over a period of two years, accompanied by photometric and spectral type variability. We confirm the T Tauri nature of one Stephenson object (StHa 48) on the basis of the presence of H{alpha} and H{beta} in emission, Li I {lambda}6708 in absorption, infrared excess and X-ray emission. Among the 52 objects observed, there were other emission line objects: 1 Ke star, 1 BQ[] star, 2 galaxies and 2 Be stars. We present a higher-resolution spectrum of StHa 62 showing permitted and forbidden lines in emission typical of BQ[] stars. Twenty five out of 30 newly observed objects failed to show H{alpha} in emission. We also present 2MASS observations for 112 StHa objects. We suggest three Stephenson objects (StHa 52, 125 and 129) to be YSOs on the basis of 2MASS, IRAS and ROSAT observations. These and all other known YSOs amongst StHa stars are found in regions of star-forming clouds in Taurus, Orion and Ophiuchus. YSOs at high galactic latitudes in other parts of the sky are therefore rare.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A85
- Title:
- Structure of Herbig AeBe disks at mas scale
- Short Name:
- J/A+A/599/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aims of this article are to infer the radial and vertical structure at ~au scale of these disks, and the properties of the dust grains: composition and characteristic size. We find that dust at the inner rim of the disk has a sublimation temperature Tsub~1800K. A ring structure is confirmed for approximately half the resolved objects; these rings are wide {delta}r/r>=0.5. Such wide rings exclude an inner rim shaped as a vertical wall, or with a rounded shape, and seem to favor an inner rim with a wedge-like cross-section. The inner disk has a thickness z/r~0.2, flaring to z/r~0.5 in the outer part. We confirm the known luminosity-radius relation; a simple physical model is consistent with both the mean luminosity-radius relation and the ring relative width; however, a significant spread around the mean relation is present. We find in some of the objects a halo component, fully resolved at the shortest interferometer spacing, that is related to the HAeBe class.
- ID:
- ivo://CDS.VizieR/J/ApJ/856/158
- Title:
- The B[e] phenomenon. VII. AS 386 follow-up
- Short Name:
- J/ApJ/856/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of spectroscopic and photometric observations of the emission-line object AS 386. For the first time we found that it exhibits the B[e] phenomenon and fits the definition of an FS CMa type object. The optical spectrum shows the presence of a B-type star with the following properties: Teff=11000+/-500K, log L/L_{sun}_=3.7+/-0.3, a mass of 7+/-1M_{sun}_, and a distance D=2.4+/-0.3kpc from the Sun. We detected regular radial velocity variations of both absorption and emission lines with the following orbital parameters: Porb=131.27+/-0.09 days, semiamplitude K1=51.7+/-3.0km/s, systemic radial velocity {gamma}=-31.8+/-2.6km/s, and a mass function of f(m)=1.9+/-0.3M_{sun}_. AS 386 exhibits irregular variations of the optical brightness (V=10.92+/-0.05mag), while the near-IR brightness varies up to ~0.3mag following the spectroscopic period. We explain this behavior by a variable illumination of the dusty disk inner rim by the B-type component. Doppler tomography based on the orbital variations of emission-line profiles shows that the material is distributed near the B-type component and in a circumbinary disk. We conclude that the system has undergone a strong mass transfer that created the circumstellar material and increased the B-type component mass. The absence of any traces of a secondary component, whose mass should be >=7M_{sun}_, suggests that it is most likely a black hole.
- ID:
- ivo://CDS.VizieR/J/A+A/416/669
- Title:
- UBV photometry of HD 6226
- Short Name:
- J/A+A/416/669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric and spectroscopic monitoring of the B star resulted in the finding that this object is a new bright Be star with a clear positive correlation between the brightness and emission-line strength. The emission-line episodes are relatively short and seem to repeat frequently which makes this star an ideal target for studying the causes of the Be phenomenon.
- ID:
- ivo://CDS.VizieR/J/A+A/387/580
- Title:
- UBV photometry of V832 Cyg
- Short Name:
- J/A+A/387/580
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of numerous homogenized UBV photoelectric observations and red spectra of the Be star from several observatories is presented.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2971
- Title:
- UBVRI photometry of 131 Herbig Ae/Be
- Short Name:
- J/AJ/126/2971
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of 108 Herbig Ae/Be candidate stars identified in the Pico dos Dias Survey (Gregorio-Hete et al., 1992AJ....103..549G; Torres et al., 1995AJ....109.2146T and 1999, Special Publ. 10, Rio de Janeiro: Obs. Nac.), together with 19 previously known candidates and four objects selected from the IRAS Faint Source Catalog (<II/156>). These 131 stars were observed with low- and/or medium-resolution spectroscopy, and we complement these data with high-resolution spectra of 39 stars.
- ID:
- ivo://CDS.VizieR/J/A+A/415/273
- Title:
- UVBRI photometry and spectroscopy of AG Dra
- Short Name:
- J/A+A/415/273
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric UBVri observations of the symbiotic star AG Dra in Piwnice Observatory, Torun, Poland, are presented in tables 2 and 3. The 60cm telescope and a single-channel photoelectric photometer have been used. Table 2 lists observations with the EMI9558B photomultiplier tube from March 1996 to September 1999. Table 3 lists observations with the cooled C31034 photomultiplier tube from October 2001 to May 2003. Table 4 lists equivalent widths (EW) of the four emission lines in the spectrum of AG Dra: The Raman scattered line at 6825{AA}, H{alpha}, H{beta} and He II 4686{AA}. The spectroscopic observations have been performed in Tartu Observatory, Estonia, using the 1.5m telescope and a Cassegrain spectrograph. The time interval extends from September 1997 to March 2003.
- ID:
- ivo://CDS.VizieR/J/ApJ/784/127
- Title:
- UV spectra of classical T Tauri stars
- Short Name:
- J/ApJ/784/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The far-ultraviolet (FUV; 912-1700 {AA}) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r<10 AU), from a gas- and dust-rich primordial disk to a transitional system where the optically thick warm dust distribution has been depleted. Previous efforts to measure the true stellar+accretion-generated FUV luminosity (both hot gas emission lines and continua) have been complicated by a combination of low-sensitivity and/or low-spectral resolution and did not include the contribution from the bright Ly{alpha} emission line. In this work, we present a high-resolution spectroscopic study of the FUV radiation fields of 16 T Tauri stars whose dust disks display a range of evolutionary states. We include reconstructed Ly{alpha} line profiles and remove atomic and molecular disk emission (from H_2_ and CO fluorescence) to provide robust measurements of both the FUV continuum and hot gas lines (e.g., Ly{alpha}, N V, C IV, He II) for an appreciable sample of T Tauri stars for the first time. We find that the flux of the typical classical T Tauri star FUV radiation field at 1 AU from the central star is ~10^7^ times the average interstellar radiation field. The Ly{alpha} emission line contributes an average of 88% of the total FUV flux, with the FUV continuum accounting for an average of 8%. Both the FUV continuum and Ly{alpha} flux are strongly correlated with C IV flux, suggesting that accretion processes dominate the production of both of these components. On average, only ~0.5% of the total FUV flux is emitted between the Lyman limit (912 {AA}) and the H_2_(0-0) absorption band at 1110 {AA}. The total and component-level high-resolution radiation fields are made publicly available in machine-readable format.
