Wide Field Multicolor CCD Photometry of the Open Cluster NGC752

2010 ◽  
Vol 19 (1-2) ◽  
Author(s):  
J. Zdanavičius ◽  
S. Bartašiutė ◽  
K. Zdanavičius
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Wide Field ◽  
Ccd Photometry ◽  
Magnitude Diagram

AbstractThe results of CCD photometry in the seven-color Vilnius system of 3058 stars down to V ~ 18.0 mag in a 1.5 square degree field around the cluster NGC 752 are presented. For most of the stars brighter than V = 17.0 mag, photometric spectral and luminosity classes are determined. The catalog of 1174 stars down to V = 15.5 mag is given in the paper. The entire catalog will be available at the CDS Simbad database. The color-magnitude diagram indicates an extension of the cluster’s main sequence down to 5 mag below the turnoff point.

A Deep Luminosity Function for 47 Tucanae

1985 ◽  
Vol 113 ◽  
pp. 81-83
Author(s):  
William E. Harris ◽  
James E. Hesser
Keyword(s):  
Luminosity Function ◽  
Main Sequence ◽  
Ccd Photometry ◽  
Magnitude Diagram

CCD photometry in B and V reaching B(lim) ≃ 25 has been employed to obtain the luminosity function and color-magnitude diagram for the main sequence of 47 Tuc. For 5<Mv<10 we find that its LF is essentially flat (Δlog n/Δm~0). The CMD is successfully matched by isochrones with [Fe/H] = −0.5 and t ≃ 15 × 109y.

scholarly journals CCD Photometry in the Globular Cluster M4

1995 ◽  
Vol 164 ◽  
pp. 411-411
Author(s):  
W.K. Griffiths ◽  
I.N. Kanatas ◽  
R.J. Dickens ◽  
A.J. Penny
Keyword(s):  
Globular Cluster ◽  
Main Sequence ◽  
Ccd Photometry ◽  
Magnitude Diagram ◽  
Red Giant

A V, B- V composite colour-magnitude diagram, based upon CCD photometry from V~ 12 on the red giant branch to V~ 25 on the main-sequence has been derived for the globular cluster M4. A distance to the cluster of (m – M)v = 12.84 ± 0.19 is determined and the best match to theoretical isochrones is for the case [Fe/H]=−1.27 and an age of 16±1 Gyr. A differential age comparison with NGC 362 shows that M4 is approximately 1.7 Gyr older.

Wide Field Multicolor CCD Photometry in the Vicinity of the Open Cluster King 7

2010 ◽  
Vol 19 (3-4) ◽  
Author(s):  
J. Zdanavičius ◽  
V. Čepas ◽  
K. Zdanavičius ◽  
V. Straižys
Keyword(s):  
Open Cluster ◽  
Wide Field ◽  
Two Dimensional ◽  
Ccd Photometry

AbstractWe present the results of CCD photometry in the seven-color Vilnius system for 1549 stars down to V ∼16 mag in a 1.5 square degree field around the cluster King 7, at the Perseus and Camelopardalis border. Using photometric parameters, two-dimensional spectral types, interstellar extinctions and distances for most of the stars are determined.

scholarly journals The extended main-sequence turn-off of the Milky Way open cluster Collinder 347

2019 ◽  
Vol 490 (2) ◽  
pp. 2414-2420 ◽  
Author(s):  
Andrés E Piatti ◽  
Charles Bonatto
Keyword(s):  
Main Sequence ◽  
Milky Way ◽  
Open Cluster ◽  
Age Difference ◽  
Proper Motions ◽  
Gaussian Distributions ◽  
Young Object ◽  
Magnitude Diagram ◽  
Chemical Content ◽  
Gaia Dr2

ABSTRACT We made use of the Gaia DR2 archive to comprehensively study the Milky Way open cluster Collinder 347, known until now as a very young object of solar metal content. However, the G versus GBP − GRP colour–magnitude diagram (CMD) of bonafide probable cluster members, selected on the basis of individual stellar proper motions, their spatial distribution, and placement in the CMD, reveals the existence of a Hyades-like age open cluster (log(t /yr) = 8.8) of moderately metal-poor chemical content ([Fe/H]  = −0.4 dex), with a present-day mass of 3.3 × 103 M⊙. The cluster exhibits an extended main-sequence turn-off (eMSTO) of nearly 500 Myr, while that computed assuming Gaussian distributions from photometric errors, stellar binarity, rotation, and metallicity spread yields an eMSTO of ∼340 Myr. Such an age difference points to the existence within the cluster of stellar populations with different ages.

scholarly journals Extended main sequence turnoffs in open clusters as seen by Gaia – II. The enigma of NGC 2509

2019 ◽  
Vol 491 (2) ◽  
pp. 2129-2136 ◽  
Author(s):  
M de Juan Ovelar ◽  
S Gossage ◽  
S Kamann ◽  
N Bastian ◽  
C Usher ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Main Sequence ◽  
Narrow Range ◽  
Open Cluster ◽  
Open Clusters ◽  
Stellar Rotation ◽  
Rotation Rates ◽  
Magnitude Diagram ◽  
Stellar Density

ABSTRACT We investigate the morphology of the colour–magnitude diagram (CMD) of the open cluster NGC 2509 in comparison with other Galactic open clusters of similar age using Gaia photometry. At ${\sim}900\,\rm {Myr}$ Galactic open clusters in our sample all show an extended main sequence turnoff (eMSTO) with the exception of NGC 2509, which presents an exceptionally narrow CMD. Our analysis of the Gaia data rules out differential extinction, stellar density, and binaries as a cause for the singular MSTO morphology in this cluster. We interpret this feature as a consequence of the stellar rotation distribution within the cluster and present the analysis with mesa Isochrones and Stellar Tracks (MIST) stellar evolution models that include the effect of stellar rotation on which we based our conclusion. In particular, these models point to an unusually narrow range of stellar rotation rates (Ω/Ωcrit, ZAMS = [0.4, 0.6]) within the cluster as the cause of this singular feature in the CMD of NGC 2509. Interestingly, models that do not include rotation are not as good at reproducing the morphology of the observed CMD in this cluster.

scholarly journals Deep CCD Photometry of Omega Centauri

1988 ◽  
Vol 126 ◽  
pp. 631-632
Author(s):  
R. G. Noble ◽  
J. Buttress ◽  
W. K. Griffiths ◽  
A. J. Penny ◽  
R. J. Dickens ◽  
...  
Keyword(s):  
Main Sequence ◽  
Ccd Camera ◽  
Ccd Photometry ◽  
Magnitude Diagram ◽  
Ccd Observations

This paper presents a color magnitude diagram for the enigmatic cluster ω Centauri (NGC 5139 = C1328 − 472) tracing the main sequence down to V ~ 21.5. The spread in color on the upper main sequence is confirmed as intrinsic to the cluster. The CCD observations were made using the SAAO 1 m telescope with the UCL CCD camera and the RGO CCD camera at the prime focus of the AAT.

scholarly journals UBVI CCD Photometry of an old Open Cluster AM-2

1996 ◽  
Vol 169 ◽  
pp. 435-436 ◽  
Author(s):  
Myung Gyoon Lee
Keyword(s):  
Globular Cluster ◽  
Main Sequence ◽  
Open Cluster ◽  
Ultraviolet Excess ◽  
Galactic Latitude ◽  
Ccd Photometry ◽  
Fitting Method ◽  
Age Ratio ◽  
Red Giant Clump ◽  
Red Giant

AM-2 is a sparse cluster located at low galactic latitude. It has been suspected to be a globular cluster. We present a study of AM-2 based on the deep UBVI CCD photometry obtained using the Las Campanas duPont 2.5m telescope. The color-magnitude diagrams of AM-2 show (a) a main-sequence extending up to V ≈ 19 mag at (B – V) ≈ 1.1 mag, (b) a small number of red giant clump giants, (c) the brightest red giant at V ≈ 16.1 mag and (B – V) ≈ 1.9 mag, and (d) a small group of mysterious blue stars at V ≈ 16.6 mag and (B – V) ≈ 0.9 mag. We have estimated the reddening using the color-color diagram, E(B – V) = 0.56 ± 0.04. The metallicity of the main-sequence stars has been estimated from the ultraviolet excess, δ(U – B)0.6 = 0.09 ± 0.04, to be [Fe/H] = −0.4 ± 0.2 dex. The distance to the cluster has been measured using the Zero-Age-Main-Sequence fitting method, (m – M)0 = 14.8 ± 0.3 (d = 9.1 ± 1.4 kpc). Finally we have estimated the age of the cluster using the Revised Yale isochrones and the Morphological Age Ratio (MAR) method, obtaining a value of 5 ± 1 Gyrs (Fig. 1). This shows that AM-2 is not a globular cluster, but an old open cluster.

scholarly journals The Absolute Magnitude and Stellar Population of a Ba II Star

1973 ◽  
Vol 54 ◽  
pp. 225-228
Author(s):  
R. D. McClure
Keyword(s):  
Stellar Population ◽  
Main Sequence ◽  
Open Cluster ◽  
Absolute Magnitude ◽  
Distance Modulus ◽  
Magnitude Diagram ◽  
The Absolute

A star showing extreme features characteristic of the Ba II stars has been found in the old open cluster NGC 2420. A new colour-magnitude diagram has been constructed for the cluster, and a distance modulus of 11m.7 is obtained by fitting the unevolved main sequence to the zero-age main sequence. The location of the Ba II star is consistent with its being a disc population star of absolute magnitude Mv = −0m.3, mass 1.4 M⊙ and age 2.4 × 109 yr.

scholarly journals Multicolor CCD photometry of the open cluster NGC 752

2009 ◽  
Vol 5 (S266) ◽  
pp. 361-364
Author(s):  
Stanislava Bartašiūtė ◽  
Robert Janusz ◽  
Richard P. Boyle ◽  
A. G. Davis Philip ◽  
Viktoras Deveikis
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Ccd Camera ◽  
Advanced Technology ◽  
Ccd Photometry ◽  
Intermediate Band ◽  
Individual Stars ◽  
Ccd Observations ◽  
Low Mass

AbstractWe obtained CCD observations of the open cluster NGC 752 with the 1.8m Vatican Advanced Technology Telescope (Mt. Graham, Arizona) with a 4K CCD camera and eight intermediate-band filters of the Stromvil (Strömgren + Vilnius) system. Four 12′ × 12′ fields were observed, covering the central part of the cluster. The good-quality multicolor data made it possible to obtain precise estimates of distance moduli, metallicity and foreground reddening for individual stars down to the limiting magnitude, V = 17.5, enabling photometric identification of faint cluster members. The new observations provide an extension of the lower main sequence to three magnitudes beyond the previous (photographic) limit. A relatively small number of photometric members identified at fainter magnitudes seems to be indicative of actual dissolution of the cluster from the low-mass end.

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