- ID:
- ivo://CDS.VizieR/J/A+A/623/A22
- Title:
- IC 4996 Vilnius phot. and Gaia DR2 astrometry
- Short Name:
- J/A+A/623/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The open cluster IC 4996 in Cygnus and its vicinity are investigated applying two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. Th interstellar extinction A(v) covers a wide range of values, from 1.3 to 2.4mag, the mean value in the central part of the cluster is 1.8mag. The cluster distance is 1915+/-110pc, and its age is within 8-10Myr. The cluster exhibits a long sequence from early B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of the extinction versus distance shows a steep rise of A(v) up to 1.6mag at 700-800pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next extinction rise by an additional 0.8 mag at d>=1.7kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682+/-116pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since the Gaia data show that these stellar groups are located at a similar distance.
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- ID:
- ivo://CDS.VizieR/J/BaltA/19/63
- Title:
- IC 361 Vilnius photometry
- Short Name:
- J/BaltA/19/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry in the eight-color Vilnius + I system for 7250 stars down to I=19.6mag has been obtained in the 20'x26' field of the open cluster IC361 in Camelopardalis. The catalog of 1420 stars down to V~18.5mag is presented. It contains the coordinates, V magnitudes, seven color indices, quantitative photometric spectral types, absolute magnitudes and distances. The interstellar extinction is found to be non-uniform across the field, with the values of A_V_ in the range 1.9 to 2.4mag. The distribution of distance moduli of individual stars shows that the cluster is located as far as, or just beyond, the Perseus spiral arm.
- ID:
- ivo://CDS.VizieR/J/AJ/159/95
- Title:
- IC 1369 Vilnius photometry and Gaia DR2 astrometry
- Short Name:
- J/AJ/159/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The open cluster IC1369, located in Cygnus close to the galactic equator at the 89.6{deg} longitude, and its vicinity are investigated by applying two-dimensional photometric classification of stars down to V=19mag measured in the Vilnius seven-color photometric system. Employing the Gaia DR2 coordinates, parallaxes, and proper motions, 143 cluster members are found having cluster membership probabilities >=0.75. The hottest stars of the evolved main sequence are of spectral class B9. Distances to the cluster, determined by two methods based on the Gaia parallaxes, are 3280 and 3370pc with an uncertainty of 400-500pc. Employing the physical HR diagram with the coordinates logL/L_{sun}_ versus logTeff and the Padova isochrones, the cluster age is found to be between 300 and 350Myr. Among the cluster members we identified six red giants of spectral classes G5-G8 and luminosities II-III, 17 Am stars, one Ap star, and one B5 blue straggler. The extinction shows a steep rise up to ~2.0mag at 300-700pc, caused by the extensions of the dust cloud LDN970 and the Great Cygnus Rift, and up to ~2.5mag at the edge of the Perseus arm at 3.0kpc. The extinction is almost constant between 0.9 and 2.5kpc from the Sun. The average extinction of the cluster members is 2.54mag. A systematic error of color excesses found in the Argonaut calculator results is discussed.
- ID:
- ivo://CDS.VizieR/J/A+AS/126/81
- Title:
- IC 2602 VRI photometry
- Short Name:
- J/A+AS/126/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of VRI photometry of the young open cluster IC 2602. Two 15x15arcmin^2^ fields were observed in February and May 1991 using the 1-m Swope telescope at Las Campanas. Using theoretical isochrones obtained from D'Antona & Mazzitelli (1994ApJS...90..467D), and allowing for observational and other uncertainties, we identify 78 primary candidate members with 12<V<18.5 from their positions on colour-magnitude diagrams. We compare the cluster field with an offset field of similar galactic latitude and estimate the contamination due to background stars to be large, >=50%, as might be expected given its low galactic latitude. We also compare our photometry with that given for the X-ray detected stars of Randich et al. (1995A&A...300..134R) present complimentary narrow band H{alpha} photometry for a subset of the stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/33
- Title:
- Improved & expanded membership catalog for NGC752
- Short Name:
- J/ApJ/862/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby open cluster NGC 752 presents a rare opportunity to study stellar properties at ages >1Gyr. However, constructing a membership catalog for it is challenging; most surveys have been limited to identifying its giants and dwarf members earlier than mid-K. We supplement past membership catalogs with candidates selected with updated photometric and proper-motion criteria, generating a list of 258 members, a >50% increase over previous catalogs. Using a Bayesian framework to fit MESA Isochrones & Stellar Tracks evolutionary models to literature photometry and the Tycho-Gaia Astrometric Solution data available for 59 cluster members, we infer the age of and distance to NGC 752: 1.34+/-0.06Gyr and 438_-6_^+8^pc. We also report the results of our optical monitoring of the cluster using the Palomar Transient Factory. We obtain rotation periods for 12 K and M cluster members, the first periods measured for such low-mass stars with a well-constrained age >1Gyr. We compare these new periods to data from the younger clusters Praesepe and NGC 6811, and to a theoretical model for angular momentum loss, to examine stellar spin-down for low-mass stars over their first 1.3Gyr. While on average NGC 752 stars are rotating more slowly than their younger counterparts, the difference is not significant. Finally, we use our spectroscopic observations to measure H{alpha} for cluster stars, finding that members earlier than ~M2 are magnetically inactive, as expected at this age. Forthcoming Gaia data should solidify and extend the membership of NGC 752 to lower masses, thereby increasing its importance for studies of low-mass stars.
- ID:
- ivo://CDS.VizieR/J/BaltA/17/1
- Title:
- Infrared photometry in GL490 star-forming region
- Short Name:
- J/BaltA/17/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the infrared photometry data extracted from the 2MASS, IRAS and MSX databases, 50 suspected young stellar objects (YSOs) are selected from about 37500 infrared objects in the 3x3deg^2^ area with the center at (l,b=142.5,+1.0), in the vicinity of the young stellar object GL 490 in the dark cloud T 942 (Dobashi et al., 2005PASJ...57S...1D, Cat. <VII/244>). The spectral energy distributions between 700nm and 100um suggest that most of the selected objects may be YSOs of classes I and II. In the color-magnitude diagram Ks vs. H-Ks the suspected YSOs occupy an area right of the main sequence what can be interpreted as being caused by the effects of luminosity, interstellar and circumstellar reddening and infrared thermal emission in circumstellar envelopes and disks.
- ID:
- ivo://CDS.VizieR/J/ApJ/581/258
- Title:
- Infrared photometry in the Arches Cluster
- Short Name:
- J/ApJ/581/258
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and use new spectra and narrowband images, along with previously published broadband images, of stars in the Arches cluster to extract photometry, astrometry, equivalent width, and velocity information. The data are interpreted with a wind/atmosphere code to determine stellar temperatures, luminosities, mass-loss rates, and abundances. We have doubled the number of known emission-line stars, and we have also made the first spectroscopic identification of the main sequence for any population in the Galactic center.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1574
- Title:
- Infrared photometry of IC348 members
- Short Name:
- J/AJ/131/1574
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near- and mid-infrared photometry obtained with the Spitzer Space Telescope of 300 known members of the IC 348 cluster. We merge this photometry with existing ground-based optical and near-infrared photometry in order to construct optical-infrared spectral energy distributions (SEDs) for all the cluster members and present a complete atlas of these SEDs.
- ID:
- ivo://CDS.VizieR/J/AJ/129/656
- Title:
- Infrared photometry of NGC 6791
- Short Name:
- J/AJ/129/656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep JHK photometry of the old and metal-rich open cluster NGC 6791. The photometry reaches below the main-sequence turnoff to K~16.5mag. We combine our photometry with that from Stetson et al. (2003, Cat. <J/PASP/115/413>) to provide color-magnitude diagrams showing K versus J-K, K versus V-K, and V versus V-K.
- ID:
- ivo://CDS.VizieR/J/ApJ/573/366
- Title:
- Infrared photometry of Trapezium cluster
- Short Name:
- J/ApJ/573/366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the results of a new multiepoch, multiwavelength, near-infrared census of the Trapezium cluster in Orion to construct and analyze the structure of its infrared (K-band) luminosity function. Specifically, we employ an improved set of model luminosity functions to derive this cluster's underlying initial mass function (IMF) across the entire range of mass from OB stars to substellar objects down to near the deuterium-burning limit. The observations were performed at FLWO (Fred Lawrence Whipple Observatory, Smithsonian Astrophysical Observatory), and ESO-NTT (European Southern Observatory, New Technology Telescope), between Dec. 1997 and Marche 2000 (see the "Table 5" section below)