- ID:
- ivo://CDS.VizieR/J/ApJ/676/1109
- Title:
- Velocities of stars in the Orion Nebula Cluster
- Short Name:
- J/ApJ/676/1109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from 1351 high-resolution spectra of 1215 stars in the Orion Nebula Cluster (ONC) and the surrounding Orion 1c association, obtained with the Hectochelle multiobject echelle spectrograph on the 6.5m MMT. We confirmed 1111 stars as members, based on their radial velocity and/or H{alpha} emission. The radial velocity distribution of members shows a dispersion of {sigma}=3.1km/s. We found a substantial north-south velocity gradient and spatially coherent structure in the radial velocity distribution, similar to that seen in the molecular gas in the region. We also identified several binary and high velocity stars, a region exhibiting signs of triggered star formation, and a possible foreground population of stars somewhat older than the ONC.
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- ID:
- ivo://CDS.VizieR/J/AJ/151/66
- Title:
- Velocities of WOCS 24009 and WOCS 40007 in NGC 6819
- Short Name:
- J/AJ/151/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of our study of the old (~2.5Gyr) open cluster NGC 6819 in the Kepler field, we present photometric (Kepler and ground-based BVR_C_I_C_) and spectroscopic observations of the detached eclipsing binary WOCS 24009 (Auner 665; KIC5023948) with a short orbital period of 3.6 days. WOCS 24009 is a triple-lined system, and we verify that the brightest star is physically orbiting the eclipsing binary using radial velocities and eclipse timing variations. The eclipsing binary components have masses M_B_=1.090+/-0.010M_{sun}_ and M_C_=1.075+/-0.013M_{sun}_, and radii R_B_=1.099+/-0.006+/-0.005R_{sun}_and R_C_=1.069+/-0.006+/-0.013R_{sun}_. The bright non-eclipsing star resides at the cluster turnoff, and ultimately its mass will directly constrain the turnoff mass: our preliminary determination is M_A_=1.251+/-0.057M_{sun}_. A careful examination of the light curves indicates that the fainter star in the eclipsing binary undergoes a very brief period of total eclipse, which enables us to precisely decompose the light of the three stars and place them in the color-magnitude diagram (CMD). We also present improved analysis of two previously discussed detached eclipsing stars in NGC6819 (WOCS40007 and WOCS23009) en route to a combined determination of the cluster's distance modulus (m-M)_V_=12.38+/-0.04. Because this paper significantly increases the number of measured stars in the cluster, we can better constrain the age of the CMD to be 2.21+/-0.10+/-0.20Gyr. Additionally, using all measured eclipsing binary star masses and radii, we constrain the age to 2.38+/-0.05+/-0.22Gyr. The quoted uncertainties are estimates of measurement and systematic uncertainties (due to model physics differences and metal content), respectively.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/231
- Title:
- Velocities & rotation of CP stars
- Short Name:
- J/A+AS/118/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of a systematic project we have determined radial velocities and projected rotational velocities for a sample of 186 chemically peculiar stars which have been observed by the Hipparcos' satellite. The purpose is to provide necessary data to study the space velocities of peculiar stars.
- ID:
- ivo://CDS.VizieR/J/A+A/544/L12
- Title:
- Velocitometry transit of KOI-13
- Short Name:
- J/A+A/544/L12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a new stellar companion in the KOI-13 system. KOI-13 is composed of two fast-rotating A-type stars of similar magnitude. One of these two stars hosts a transiting planet discovered by Kepler. We obtained new radial velocity measurements using the SOPHIE spectrograph at the Observatoire de Haute-Provence that reveal an additional companion in this system. This companion has a mass of between 0.4M_{sun}_ and 1M_{sun}_ and orbits one of the two main stars with a period of 65.831+/-0.029-days and an eccentricity of 0.52+/-0.02.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A63
- Title:
- Velocitometry transit of KOI-428b
- Short Name:
- J/A+A/528/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a hot Jupiter transiting a subgiant star with an orbital period of 6.87-days thanks to public photometric data from the Kepler space mission and new radial velocity observations obtained by the SOPHIE spectrograph. The planet KOI-428b with a radius of 1.17+/-0.04R_Jup_ and a mass of 2.2+/-0.4M_Jup_, orbits around a F5IV star with R*=2.13+/-0.06R_{sun}_, M*=1.48+/-0.06M_{sun} and Teff=6510+/-100K. The star KOI-428 is the largest and the most evolved star discovered so far with a transiting planet
- ID:
- ivo://CDS.VizieR/J/other/ChJAA/3.49
- Title:
- Velocity and distance of methanol maser sources
- Short Name:
- J/other/ChJAA/3.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical analysis of 482 6.7GHz methanol maser sources from the available literature, on their maser emission and the characteristics of their associated infrared sources. On the color-color diagram, more than 70% of the objects fall within a very small region (0.57<=[25-12]<=1.30 and 1.30<=[60-12]<=2.50). This suggests that 6.7GHz methanol maser emission occurs only within a very short evolutionary phase during the earliest stage of star formation. The velocity ranges of the masers belong to two main groups: one from 1 to 10km/s, and one from about 11 to 20km/s. These velocity ranges indicate that the masers are probably associated with both disks and outflows. The correlations between the maser and infrared flux densities, and between the maser and infrared luminosities, suggest that far-infrared radiation is a possible pumping mechanism for the masers which most probably originate from some outer molecular envelopes or disks.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2669
- Title:
- Velocity and H{alpha} width of 22 Vul
- Short Name:
- J/AJ/133/2669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 22 Vul system is important for studying the winds and chromospheres of cool evolved stars because the G4 I component is rotating rapidly and probably faster than synchronously. We discuss the system's physical properties in the context of a wide range of constraints on them and propose values that may be marginally better than previous ones. We use H{alpha} spectroscopy to assess the variability of the cool star's wind, and archival IUE observations to measure variation of density in the wind and rotation of the chromosphere.
- ID:
- ivo://CDS.VizieR/J/AJ/156/300
- Title:
- Velocity and light curve analysis of three PPNe
- Short Name:
- J/AJ/156/300
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained contemporaneous light, color, and radial velocity data for three proto-planetary nebulae (PPNe) over the years 2007 to 2015. The light and velocity curves of each show similar periods of pulsation, with photometric periods of 42 and 50 days for IRAS 17436+5003, 102 days for IRAS 18095+2704, and 35 days for IRAS 19475+3119. The light and velocity curves are complex with multiple periods and small, variable amplitudes. Nevertheless, at least over limited time intervals, we were able to identify dominant periods in the light, color, and velocity curves and compare the phasing of each. The color curves appear to peak with or slightly after the light curves while the radial velocity curves peak about a quarter of a cycle before the light curves. Similar results were found previously for two other PPNe, although for them the light and color appeared to be in phase. Thus, it appears that PPNe are brightest when smallest and hottest. These phase results differ from those found for classical Cepheid variables, where the light and velocity differ by half a cycle, and are hottest at about average size and expanding. However, they do appear to have similar phasing to the larger-amplitude pulsations seen in RV Tauri variables. Presently, few pulsation models exist for PPNe, and these do not fit the observations well, especially the longer periods observed. Model fits to these new light and velocity curves would allow masses to be determined for these post-AGB objects, and thereby provide important constraints to post-AGB stellar evolution models of low- and intermediate-mass stars.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2838
- Title:
- Velocity and light curves of RW Lac
- Short Name:
- J/AJ/130/2838
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 3004 differential observations in the V bandpass measured by a robotic telescope, as well as 36 pairs of radial velocities from high-resolution spectroscopic observations, of the detached, eccentric, EA-type, 10.37day period, double-lined eclipsing binary star RW Lac.
- ID:
- ivo://CDS.VizieR/J/MNRAS/400/518
- Title:
- Velocity and proper motion of OB associations
- Short Name:
- J/MNRAS/400/518
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The proper motions of OB-associations computed using the old (1997, Cat. <I/239>) and new (2008, Cat. <I/311>) reductions of the Hipparcos data are in a good agreement with each other. The Galactic rotation curve derived from the analysis of line-of-sight velocities and proper motions of OB-associations is almost flat in the 3-kpc neighborhood of the Sun. The angular rotation velocity at the solar distance is Omega_0_=31(+/-1)km/s/kpc. The standard deviation of the velocities of OB-associations from the rotation curve is sigma=7.2km/s. The distance scale for OB associations by Blaha and Humpreys (1989AJ.....98.1598B) should be shortened by 10-20%. The residual velocities of OB-associations calculated for the new and old reductions differ, on average, by 3.5km/s. The mean residual velocities of OB-associations in the stellar-gas complexes depend slightly on the data reduction employed.
