The open cluster NGC 7142: interstellar extinction, distance and age

Straižys, V.; Maskoliunas, M.; Boyle, R. P.; Zdanavičius, K.; Zdanavicius, J.; Laugalys, V.; Kazlauskas, A.

doi:10.1093/mnras/stt1995

Cited by 12 publications

(9 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, 4289 is a member of a binary with a period of 11.49 days , which is consistent with the hypothesis that the X-rays result from rapid rotation in the synchronized primary member of the binary. 1141 is a RS and also an X-ray source (Belloni et al 1998, X5), and references therein) and Straižys et al (2014). For the globular clusters we take the age from Marín-Franch et al…”

Section: Open Cluster Observationsmentioning

confidence: 99%

On the Origin of Sub-subgiant Stars. I. Demographics

Geller

Leiner

Bellini

et al. 2017

ApJ

View full text Add to dashboard Cite

Sub-subgiants are stars observed to be redder than normal main-sequence stars and fainter than normal subgiant (and giant) stars in an optical color-magnitude diagram. The red straggler stars, which lie redward of the red giant branch, may be related and are often grouped together with the sub-subgiants in the literature. These stars defy our standard theory of single-star evolution, and are important tests for binary evolution and stellar collision models. In total, we identify 65 sub-subgiants and red stragglers in 16 open and globular star clusters from the literature; 50 of these, including 43 sub-subgiants, pass our strict membership selection criteria (though the remaining sources may also be cluster members). In addition to their unique location on the color-magnitude diagram, we find that at least 58% (25/43) of sub-subgiants in this sample are X-ray sources with typical 0.5-2.5 keV luminosities of order 10 30−31 erg s −1 . Their X-ray luminosities and optical-to-X-ray flux ratios are similar to those of RS CVn active binaries. At least 65% (28/43) of the sub-subgiants in our sample are variables, 21 of which are known to be radial-velocity binaries. Typical variability periods are 15 days. At least 33% (14/43) of the sub-subgiants are Hα emitters. These observational demographics provide strong evidence that binarity is important for sub-subgiant formation. Finally, we find that the number of sub-subgiants per unit mass increases toward lower-mass clusters, such that the open clusters in our sample have the highest specific frequencies of sub-subgiants.

show abstract

Section: Open Cluster Observationsmentioning

confidence: 99%

On the Origin of Sub-subgiant Stars. I. Demographics

Geller

Leiner

Bellini

et al. 2017

ApJ

View full text Add to dashboard Cite

show abstract

“…2 -0.6 15000 · · · · · · · · · 3.23 · · · · · · 1 0.05 0.006 0.001 0.026 0.27 0.33 NGC 2682 4 0.0 2100±600 0.57±0.04 0.59±0.07 · · · 1 · · · 12.1±1.3 2 0.05 0.05 0.1 0.0 0.47 0.2 NGC 6791 8 0.4 4600±1500 · · · 0.62±0.1 · · · 3.4 · · · · · · 5 0.086 0.004 0.03 0.04 0.82 0.04 NGC 6819 2.4 0.0 2600 0.4±0.02 · · · · · · 1.75 · · · 6.2±1.1 1 0.016 0.005 0.001 0.008 0.12 0.15 NGC 7142 3.6 0.1 500 · · · · · · · · · 3.1 · · · · · · 0 0.009 0.00013 0.0003 0.0045 0. Meibom et al (2009) Straižys et al (2014), and take rc from Kharchenko et al (2013). For the globular clusters we take the age from Marín-Franch et al (2009, using the "G00 CG " values and normalized using the age of 47 Tuc from Thompson et al 2010), [Fe/H], σ 0 (where available), M cl and log ρ 0 (both calculated assuming a mass-to-light ratio of 2), rc, r hm from Harris (1996Harris ( , 2010, and f b (where available) from Milone et al (2012).…”

Section: Monte Carlo Modelsunclassified

On the Origin of Sub-subgiant Stars. III. Formation Frequencies

Geller

Leiner

Chatterjee

et al. 2017

ApJ

View full text Add to dashboard Cite

Sub-subgiants are a new class of stars that are optically redder than normal main-sequence stars and fainter than normal subgiant stars. Sub-subgiants, and the possibly related red stragglers (which fall to the red of the giant branch), occupy a region of the color-magnitude diagram that is predicted to be devoid of stars by standard stellar evolution theory. In previous papers we presented the observed demographics of these sources and defined possible theoretical formation channels through isolated binary evolution, the rapid stripping of a subgiant's envelope, and stellar collisions. Sub-subgiants offer key tests for single-and binary-star evolution and stellar collision models. In this paper, we synthesize these findings to discuss the formation frequencies through each of these channels. The empirical data, our analytic formation rate calculations, and analyses of sub-subgiants in a large grid of Monte Carlo globular cluster models suggest that the binary evolution channels may be the most prevalent, though all channels appear to be viable routes to sub-subgiant creation (especially in higher-mass globular clusters). Multiple formation channels may operate simultaneously to produce the observed sub-subgiant population. Finally, many of these formation pathways can produce stars in both the sub-subgiant and red straggler (and blue straggler) regions of the color-magnitude diagram, in some cases as different stages along the same evolutionary sequence.

show abstract

“…Nevertheless, even for stars above the turn-off in NGC 7142, we could find only a few binary stars after the mass transfer. There could probably be five blue stragglers (see Figures 3 and 4 in Straizys et al (2014)) and 1-2 evolved (yellow) stragglers among the upper part of CMD.…”

mentioning

confidence: 99%

Unresolved Binaries and Galactic Clusters’ Mass Estimates

Borodina

Seleznev

Carraro

et al. 2019

ApJ

View full text Add to dashboard Cite

Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters' mass by star counts. We start from the luminosity functions of five open clusters: IC 2714, NGC 1912, NGC 2099. Luminosity functions are obtained via star counts extracted from the 2MASS database. The fraction of binaries is considered to be independent on stellar magnitude. We take into account different assumptions for the binary mass ratio distribution and assign binary masses using the so-called luminosity-limited pairing method and Monte-Carlo simulations. We show that cluster masses increase when binary stars are appropriately taken into account.

show abstract

The open cluster NGC 7142: interstellar extinction, distance and age

Cited by 12 publications

References 32 publications

On the Origin of Sub-subgiant Stars. I. Demographics

On the Origin of Sub-subgiant Stars. I. Demographics

On the Origin of Sub-subgiant Stars. III. Formation Frequencies

Unresolved Binaries and Galactic Clusters’ Mass Estimates

Contact Info

Product

Resources

About