- ID:
- ivo://CDS.VizieR/J/MNRAS/421/3325
- Title:
- 2 new candidate luminous blue variables
- Short Name:
- J/MNRAS/421/3325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two new Galactic candidate luminous blue variable (LBV) stars via detection of circular shells (typical of confirmed and candidate LBVs) and follow-up spectroscopy of their central stars. The shells were detected at 22um in the archival data of the Mid-Infrared All Sky Survey carried out with the Wide-field Infrared Survey Explorer (WISE). Follow-up optical spectroscopy of the central stars of the shells conducted with the renewed Southern African Large Telescope (SALT) showed that their spectra are very similar to those of the well-known LBVs P Cygni and AG Car, and the recently discovered candidate LBV MN112, which implies the LBV classification for these stars as well.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/156/90
- Title:
- New catalog of APOGEE radial velocity standard stars
- Short Name:
- J/AJ/156/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of 18080 radial velocity (RV) standard stars selected from the APOGEE data. These RV standard stars are observed at least three times and have a median stability (3{sigma}_RV_) around 240 m/s over a time baseline longer than 200 days. They are largely distributed in the northern sky and could be extended to the southern sky by the future APOGEE-2 survey. Most of the stars are red giants (J-K_s_>=0.5) owing to the APOGEE target selection criteria. Only about 10 per cent of them are main-sequence stars. The H-band magnitude range of the stars is 7-12.5 mag with the faint limit much fainter than the magnitudes of previous RV standard stars. As an application, we show the new set of standard stars to determine the RV zero points of the RAVE, the LAMOST, and the Gaia-RVS Galactic spectroscopic surveys.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/333
- Title:
- 2112 new 21-cm line measurements
- Short Name:
- J/A+AS/130/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains 2112 new 21-cm neutral hydrogen line measurements carried out with the meridian transit Nancay radiotelescope. Among these data we give also 213 new radial velocities which complement those listed in three previous papers of this series. Table2.dat is the list of corrected astrophysical HI-parameters (name, coordinates, systemic heliocentric velocity, line-width at two levels, log of maximum circular velocity, HI-flux and signal to noise ratio) The folder fig5 contains the files page01.ps, page02.ps ... corresponding to Figure 5, i.e. the HI-profiles of the galaxies listed in table2.dat.
- ID:
- ivo://CDS.VizieR/J/AJ/155/106
- Title:
- New Doppler velocity measurements of GJ 876
- Short Name:
- J/AJ/155/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gliese 876 harbors one of the most dynamically rich and well-studied exoplanetary systems. The nearby M4V dwarf hosts four known planets, the outer three of which are trapped in a Laplace mean-motion resonance. A thorough characterization of the complex resonant perturbations exhibited by the orbiting planets, and the chaotic dynamics therein, is key to a complete picture of the system's formation and evolutionary history. Here we present a reanalysis of the system using 6 yr of new radial velocity (RV) data from four instruments. These new data augment and more than double the size of the decades-long collection of existing velocity measurements. We provide updated estimates of the system parameters by employing a computationally efficient Wisdom-Holman N-body symplectic integrator, coupled with a Gaussian process (GP) regression model to account for correlated stellar noise. Experiments with synthetic RV data show that the dynamical characterization of the system can differ depending on whether a white-noise or correlated-noise model is adopted. Despite there being a region of stability for an additional planet in the resonant chain, we find no evidence for one. Our new parameter estimates place the system even deeper into resonance than previously thought and suggest that the system might be in a low-energy, quasi-regular double apsidal corotation resonance. This result and others will be used in a subsequent study on the primordial migration processes responsible for the formation of the resonant chain.
- ID:
- ivo://CDS.VizieR/J/A+A/440/403
- Title:
- 109 new Galactic open clusters
- Short Name:
- J/A+A/440/403
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a list of 130 Galactic Open Clusters, found in the All-Sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5). For these clusters we determined a homogeneous set of astrophysical parameters such as size, membership, motion, distance and age. In a previous work (Cat. J/A+A/438/1163), 520 already-known open clusters out of a sample of 1700 clusters from the literature were confirmed in the ASCC-2.5 using independent, objective methods. Using these methods the whole sky was systematically screened for new clusters. The newly detected clusters show the same distribution over the sky as the known ones. It is found that without the a priori knowledge about existing clusters our search lead to clusters which are, on average, brighter, have more members and cover larger angular radii than the 520 previously-known ones.
- ID:
- ivo://CDS.VizieR/J/ApJ/478/603
- Title:
- New Herbig-Haro flows in L1448 and L1455
- Short Name:
- J/ApJ/478/603
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a deep narrowband H{alpha} and [S II] optical survey of a roughly 1deg^2^ region containing L1448 and L1455 in the southwestern region of the Perseus molecular cloud. We report the detection of 13 new groups of Herbig-Haro (HH) objects in this region. The L1448 core contains eight groups of Herbig-Haro objects (HH 193, HH 194, HH 195, HH 196, HH 197, HH 267, HH 268, and HH 277). Many of the new HH objects near L1448 have orientations similar to the L1448C molecular jet and L1448 IRS3 outflow. All four known infrared sources in L1448 power Herbig-Haro objects. L1448 IRS 1 is the likely source of HH 194, HH 195E, and possibly HH 268. L1448 IRS 2 drives HH 195, and L1448 IRS 3 may power HH 196 and possibly HH 193. HH 267 and HH 277 lie close to the axes of the IRS 2 and IRS 3 flows and may also be powered by one of these sources. Finally, the class 0 source L1448C powers HH 197. The L1455 core contains five new groups of HH objects (HH 278, HH 279, HH 280, HH 317, and HH 318). L1455 IRS 1 and L1455 IRS 2 are likely to power HH objects, but a unique association between each IRAS source and a specific HH object is difficult to make. Both clouds contain some HH objects whose driving sources cannot be conclusively identified. Most of the new HH objects are located near the cloud edges while some are in the interclump medium (ICM) more than 1pc from the nearest cloud core or known young stellar object. These observations provide further evidence that HH flows can extend far beyond the cloud cores containing their sources, and in some cases extend over greater distances than associated high-velocity millimeter-wavelength CO emission. Herbig-Haro objects associated with the terminal working surfaces of outflows located in the ICM can be used to probe the nature of the interclump gas in molecular clouds. The large number of HH objects found in relatively inactive star forming regions such as L1448 and L1455 indicates that shock heating and acceleration by protostellar outflows plays an important role in determining the ionization state and energetics of the ICM that surrounds low-mass star forming regions.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1598
- Title:
- New high proper motion stars in the northern sky
- Short Name:
- J/AJ/125/1598
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We define an enhanced spectral classification scheme for M dwarf stars and use it to derive spectral classification of 104 northern stars with proper motions larger than 0.5"/yr that we discovered in a survey of high proper motion stars at low Galactic latitudes. The final tally is as follows: 54 M dwarfs, 25 sdK and sdM subdwarfs, 14 esdK and esdM extreme subdwarfs, and 11 DA and DC white dwarfs. Among the most interesting cases, we find one star to be the coolest subdwarf ever reported (LSR 2036+5059, with spectral type sdM7.5), a new M9.0 dwarf only about 6 pc distant (LSR 1835+3259), and a new M6.5 dwarf only 7 pc from the Sun (LSR 2124+4003). Spectroscopic distances suggests that 27 of the M dwarfs, three of the white dwarfs, and one of the subdwarfs (LSR 2036+5059) are within 25 pc of the Sun, making them excellent candidates for inclusion in the solar neighborhood census. Estimated sky-projected velocities suggest that most of our subdwarfs and extreme subdwarfs have halo kinematics. We find that several white dwarfs and nonmetal-poor M dwarfs also have kinematics consistent with the halo, and we briefly discuss their possible origin.
- ID:
- ivo://CDS.VizieR/J/PASP/130/H4203
- Title:
- Newly spectroscopically confirmed DB white dwarfs
- Short Name:
- J/PASP/130/H4203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a machine learning (ML) method, we mine DB white dwarfs (DBWDs) from the Sloan Digital Sky Survey (SDSS) Data Release (DR) 12 and DR14. The ML method consists of two parts: feature extraction and classification. The least absolute shrinkage and selection operator (LASSO) is used for the spectral feature extraction by comparing high quality data of a positive sample group with negative sample groups. In both the training and testing sets, the positive sample group is composed of a selection of 300 known DBWDs, while the negative sample groups are obtained from all types of SDSS spectra. In the space of the LASSO detected features, a support vector machine is then employed to build classifiers that are used to separate the DBWDs from the non-DBWDs for each individual type. Depending on the classifiers, the DBWD candidates are selected from the entire SDSS data set. After visual inspection, 2808 spectra (2029 objects) are spectroscopically confirmed. By checking the samples with the literature, there are 58 objects with 60 spectra that are newly identified, including a newly discovered AM CVn. Finally, we measure their effective temperatures (T_eff_), surface gravities (log g), and radial velocities, before compiling them into a catalog.
- ID:
- ivo://CDS.VizieR/J/AJ/153/36
- Title:
- New minima timings and RVs for 3 eclipsing binaries
- Short Name:
- J/AJ/153/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing binaries remain crucial objects for our understanding of the universe. In particular, those that are components of multiple systems can help us solve the problem of the formation of these systems. Analysis of the radial velocities together with the light curve produced for the first time precise physical parameters of the components of the multiple systems V773 Cas, QS Aql, and BR Ind. Their visual orbits were also analyzed, which resulted in slightly improved orbital elements. What is typical for all these systems is that their most dominant source is the third distant component. The system V773 Cas consists of two similar G1-2V stars revolving in a circular orbit and a more distant component of the A3V type. Additionally, the improved value of parallax was calculated to be 17.6 mas. Analysis of QS Aql resulted in the following: the inner eclipsing pair is composed of B6V and F1V stars, and the third component is of about the B6 spectral type. The outer orbit has high eccentricity of about 0.95, and observations near its upcoming periastron passage between the years 2038 and 2040 are of high importance. Also, the parallax of the system was derived to be about 2.89 mas, moving the star much closer to the Sun than originally assumed. The system BR Ind was found to be a quadruple star consisting of two eclipsing K dwarfs orbiting each other with a period of 1.786 days; the distant component is a single-lined spectroscopic binary with an orbital period of about 6 days. Both pairs are moving around each other on their 148 year orbit.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/409
- Title:
- New nearby dwarf galaxy candidates list
- Short Name:
- J/A+AS/127/409
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To increase completeness of the distance limited sample of nearby galaxies from the Kraan-Korteweg & Tammann (1979AN....300..181K) catalogue we undertook a search for small companions of larger known galaxies which have corrected radial velocities with in 500km/s. Based primarely on the POSS-II and ESO/SERC films we found 260 nearby dwarf galaxy candidates with angular diameters a>0.5arcmin. More than 50% of the objects were revealed for the first time. As we suppose, a significant part of them (about 30%) may really belong to the Local Volume sample.
