scholarly journals Pre-main-sequence variable stars in young open cluster NGC 1893

2012 ◽  
Vol 427 (2) ◽  
pp. 1449-1462 ◽  
Author(s):  
Sneh Lata ◽  
A. K. Pandey ◽  
W. P. Chen ◽  
G. Maheswar ◽  
Neelam Chauhan
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Variable Stars ◽  
Young Open Cluster

scholarly journals Main-sequence variable stars in young open cluster NGC 1893

2014 ◽  
Vol 442 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Sneh Lata ◽  
Ram Kesh Yadav ◽  
A. K. Pandey ◽  
Andrea Richichi ◽  
C. Eswaraiah ◽  
...  
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Variable Stars ◽  
Young Open Cluster

scholarly journals Stellar Content of the Young Open Cluster NGC 6823

2000 ◽  
Vol 176 ◽  
pp. 499-500
Author(s):  
A. Pigulski ◽  
Z. Kolaczkowski ◽  
G. Kopacki
Keyword(s):  
Main Sequence ◽  
Evolutionary Rate ◽  
Open Cluster ◽  
Variable Stars ◽  
Period Change ◽  
Stellar Content ◽  
Preliminary Results ◽  
The Future ◽  
Young Open Cluster

AbstractThe preliminary results of the CCD search for variable stars in the very young open cluster NGC 6823 are presented. About ten new variable stars were discovered. The most interesting finding is that of the two pre-main sequence (PMS) δ Scuti-type variables. Because the evolutionary rate of period change is large at the PMS stage, these stars could be used in the future for testing it observationally.

scholarly journals NGC 1893: a young open cluster rich in multitype variable stars

2018 ◽  
Vol 482 (1) ◽  
pp. 658-697
Author(s):  
Hui-Fang Xue ◽  
Jian-Ning Fu ◽  
Nami Mowlavi ◽  
Sophie Saesen ◽  
Fabio Barblan ◽  
...  
Keyword(s):  
Open Cluster ◽  
Variable Stars ◽  
Young Open Cluster

scholarly journals Photometric, kinematic, and variability study in the young open cluster NGC 1960

2020 ◽  
Vol 492 (3) ◽  
pp. 3602-3621 ◽  
Author(s):  
Y C Joshi ◽  
J Maurya ◽  
A A John ◽  
A Panchal ◽  
S Joshi ◽  
...  
Keyword(s):  
Open Cluster ◽  
Mass Range ◽  
Mass Function ◽  
Variable Stars ◽  
B Stars ◽  
V Band ◽  
Short Period ◽  
Young Open Cluster ◽  
Mass Segregation ◽  
Variability Study

ABSTRACT We present a comprehensive photometric analysis of a young open cluster NGC 1960 (= M36) along with the long-term variability study of this cluster. Based on the kinematic data of Gaia DR2, the membership probabilities of 3871 stars are ascertained in the cluster field among which 262 stars are found to be cluster members. Considering the kinematic and trigonometric measurements of the cluster members, we estimate a mean cluster parallax of 0.86 ± 0.05 mas and mean proper motions of μRA = −0.143 ± 0.008 mas yr−1 and μDec. = −3.395 ± 0.008 mas yr−1. We obtain basic parameters of the cluster such as E(B − V) = 0.24 ± 0.02 mag, log(Age/yr) = 7.44 ± 0.02, and d = 1.17 ± 0.06 kpc. The mass function slope in the cluster for the stars in the mass range of 0.72–7.32 M⊙ is found to be γ = −1.26 ± 0.19. We find that mass segregation is still taking place in the cluster which is yet to be dynamically relaxed. This work also presents first high-precision variability survey in the central 13 arcmin × 13 arcmin region of the cluster. The V-band photometric data accumulated on 43 nights over a period of more than 3 yr reveals 76 variable stars among which 72 are periodic variables. Among them, 59 are short period (P < 1 d) and 13 are long period (P > 1 d). The variable stars have V magnitudes ranging between 9.1 to 19.4 mag and periods between 41 min and 10.74 d. On the basis of their locations in the H–R diagram, periods, and characteristic light curves, 20 periodic variables belong to the cluster are classified as 2 δ-Scuti, 3 γ-Dor, 2 slowly pulsating B stars, 5 rotational variables, 2 non-pulsating B stars, and 6 as miscellaneous variables.

scholarly journals Interstellar polarization and extinction towards the young open cluster NGC 1502

2018 ◽  
Vol 615 ◽  
pp. A166 ◽  
Author(s):  
G. A. Topasna ◽  
N. T. Kaltcheva ◽  
E. Paunzen
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Extinction Ratio ◽  
Color Excess ◽  
Young Open Cluster ◽  
Multi Wavelength ◽  
Solar Metallicity ◽  
The Individual ◽  
Photometric Distance ◽  
Selective Extinction

Aims. NGC 1502 is located at the periphery of the Cam OB1 association and probably within the Orion Spur, with published distance estimates varying between 0.7 and 1.5 kpc. We combine new polarimetric observations and existing uvbyβ and UBV photometries to provide new estimates of the cluster’s parameters. Methods. We present new multi-wavelength polarization observations of 22 stars in the direction of the cluster and, using the wavelength of maximum polarization, calculate the total-to-selective extinction ratio for each of these stars. These are combined with homogenized uvbyβ and UBV photometries to obtain the individual stellar distances and study the structure of the field. Results. We found no evidence of significant extinction variation across the cluster and obtained an average color excess E(b − y) = 0.56 ± 0.02 mag, corresponding to E(B − V) = 0.76 mag. Given the uniformity of both pmax and λmax toward the cluster and the distribution of the color excess with distance, it seems likely that the polarization in this region arises from aligned dust grains in the foreground of the cluster, not farther than 500–600 pc. Based on 20 stars located beyond 500 pc within the studied field of view, we obtained an average polarization-based total-to-selective extinction ratio R = 2.83 ± 0.14 yielding visual absorption AV = 2.14 ± 0.16 mag. Using 11 stars with uvbyβ data that represent the main sequence of the cluster, we calculated a photometric distance of 1117−89+96 pc. This estimate is fully supported by the UBV -based analysis and the new individual membership probabilities that we derive. Assuming a solar metallicity yields an age of 5 Myr. Our analysis yields controversial results regarding the membership of the stars associated with the SZ Cam system (HD 25638 and HD 25639) to the cluster.

scholarly journals Search for variable stars in the young open cluster Stock 18

2017 ◽  
Vol 152 ◽  
pp. 01024
Author(s):  
Tirthendu Sinha ◽  
Saurabh Sharma ◽  
Rakesh Pandey ◽  
A.K. Pandey
Keyword(s):  
Open Cluster ◽  
Variable Stars ◽  
Young Open Cluster

scholarly journals From the Top to the Bottom of the Main Sequence: A Complete Mass Function of the Young Open Cluster M35

2001 ◽  
Vol 546 (2) ◽  
pp. 1006-1018 ◽  
Author(s):  
David Barrado y Navascues ◽  
John R. Stauffer ◽  
Jerome Bouvier ◽  
Eduardo L. Martin
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Mass Function ◽  
Young Open Cluster

scholarly journals Variable stars in young open cluster NGC 2244

2019 ◽  
Vol 487 (3) ◽  
pp. 3505-3522 ◽  
Author(s):  
Gabriela Michalska
Keyword(s):  
Near Infrared ◽  
Open Cluster ◽  
Variable Stars ◽  
Eclipsing Binaries ◽  
Class I ◽  
Be Stars ◽  
Membership Probability ◽  
Young Open Cluster ◽  
Stellar Sources ◽  
Scuti Stars

ABSTRACT We present results of a UBVIC variability survey in the young open cluster NGC 2244. In total, we found 245 variable stars. Most of them, 211 stars, are variables with irregular variations. Furthermore, 23 periodic variables were found. We also detected four candidates for δ Scuti stars and seven eclipsing binaries. Based on the mid-infrared Spitzer and WISE photometry and near infrared JHKS 2MASS photometry, we classified 104 young stellar sources among our variables: 1 Class I object, 1 Class I/flat spectrum object, 4 flat spectrum objects, 91 Class II objects, and 7 transition disc objects. This classification, together with r′i′Hα IPHAS photometry and JHK UKIDSS photometry, were used for identification of pre-main sequence stars among irregular and periodic variables. In this way, 97 CTTS candidates (96 irregular and one periodic variable), 68 WTTS candidates (54 irregular and 14 periodic variables), and 6 Herbig Ae/Be stars were found. For 223 variable stars we calculated membership probability based on proper motions from Gaia DR2 catalogue. Majority of them, 143 stars, are cluster members with probability greater than 70 per cent. For only 36 variable stars the membership probability is smaller than 20 per cent.

scholarly journals Triggered massive star formation in the open cluster NGC 1893

2003 ◽  
Vol 212 ◽  
pp. 562-563
Author(s):  
Amparo Marco ◽  
Ignacio Negueruela
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Massive Star ◽  
Main Sequence ◽  
Open Cluster ◽  
Star Forming ◽  
Young Open Cluster ◽  
H Ii Region ◽  
Pms Stars ◽  
Bright Emission

We have carried out a search for emission line pre-main sequence (PMS) stars in the area of the star-forming young open cluster NGC 1893 by means of slitless spectroscopy. We find 19 emission line stars with spectral types spanning the range from early B-type to G-type. All the PMS stars are confined to two small regions: the outer rim of the molecular cloud associated with the H ii region IC 410 and the vicinity of the bright emission cometary nebulae Sim 129 and Sim 130. The overall spatial distribution of PMS stars strongly suggests, that present day star formation in NGC 1893 is triggered by the O-type stars in the cluster.

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