Results 21 to 30 of about 365 (142)

On the Origin of the Split Main Sequences of the Young Massive Cluster NGC 1856

The Astrophysical Journal, 2023
The detection of split main sequences (MSs) associated with young clusters (≲600 Myr) has attracted a lot of attention. A prevailing scenario is that a bimodality of stellar rotation distribution drives the bifurcation of the MS. Nevertheless, the origin
Li Wang, Chengyuan Li, Long Wang, Chenyu He, Chen Wang   +4 more
doaj   +1 more source

Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler “Superstamp” Field

The Astronomical Journal, 2023
NGC 6819 is an open cluster of age 2.4 Gyr that was in the NASA Kepler spacecraft’s field of view from 2009 to 2013. The central part of the cluster was observed in a 200 × 200 pixel “superstamp” during these four years in 30 minute cadence photometry ...
Joyce A. Guzik, Andrzej S. Baran, Sachu Sanjayan, Péter Németh, Anne M. Hedlund, Jason Jackiewicz, Lori R. Dauelsberg   +6 more
doaj   +1 more source

Ecology of Blue Straggler Stars

, 2014
Ecology of Blue Straggler Stars, H.M.J. Boffin, G. Carraro & G.
Boffin, H. M. J., Carraro, G., Beccari, G.   +2 more
openaire   +4 more sources

Empirical Measurement of the Dynamical Ages of Three Globular Clusters and Some Considerations on the Use of the Dynamical Clock

The Astrophysical Journal, 2023
We have used the “dynamical clock” to measure the level of dynamical evolution reached by three Galactic globular clusters (namely, NGC 3201, NGC 6316, and NGC 6440).
Francesco R. Ferraro, Barbara Lanzoni, Enrico Vesperini, Mario Cadelano, Dan Deras, Cristina Pallanca   +5 more
doaj   +1 more source

M67 Blue Stragglers with High-resolution Infrared Spectroscopy

The Astronomical Journal, 2023
We report on the first detailed infrared chemical analysis of five binary members (S277, S997, S975, S1031, and S1195) in the open cluster M67 (NGC 2682).
K. E. Brady, C. Sneden, C. A. Pilachowski, Melike Afşar, G. N. Mace, D. T. Jaffe, N. M. Gosnell, R. Seifert   +7 more
doaj   +1 more source

A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster

The Astrophysical Journal Letters, 2023
We report metallicities for three ∼Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields results in good ...
B. Thorsbro, R. Forsberg, G. Kordopatis, A. Mastrobuono-Battisti, R. P. Church, R. M. Rich, N. Ryde, M. Schultheis, S. Nishiyama   +8 more
doaj   +1 more source

UOCS-IX. AstroSat/UVIT Study of the Open Cluster NGC 2818: Blue Stragglers, Yellow Stragglers, Planetary Nebula, and their Membership

The Astrophysical Journal, 2023
We present the first far-UV (FUV) imaging results of the intermediate-age Galactic open cluster NGC 2818 that has a planetary nebula (PN) within the field using images taken from the Ultra Violet Imaging Telescope (UVIT) aboard AstroSat.
Sharmila Rani, Gajendra Pandey, Annapurni Subramaniam, N. Kameswara Rao   +3 more
doaj   +1 more source

Investigating 16 Open Clusters in the Kepler/K2–Gaia DR3 Field. I. Membership, Binary Systems, and Rotation

The Astrophysical Journal Supplement Series, 2023
Using data from Gaia Data Release 3 and Kepler/K2, we present a catalog of 16 open clusters with ages ranging from 4–4000 Myr that provides detailed information on membership, binary systems, and rotation. We assess the memberships in 5D phase space, and
Liu Long, Shaolan Bi, Jinghua Zhang, Xianfei Zhang, Liyun Zhang, Zhishuai Ge, Tanda Li, Xunzhou Chen, YaGuang Li, LiFei Ye, TianCheng Sun, JianZhao Zhou   +11 more
doaj   +1 more source

Nonstandard Modeling of a Possible Blue Straggler Star, KIC 11145123 [PDF]

The Astrophysical Journal, 2021
Abstract Nonstandard modeling of KIC 11145123, a possible blue straggler star, has been asteroseismically carried out based on a scheme to compute stellar models with the chemical compositions in their envelopes arbitrarily modified, mimicking the effects of some interactions with other stars through which blue straggler stars are ...
Yoshiki Hatta, Takashi Sekii, Masao Takata, Othman Benomar   +3 more
openaire   +2 more sources

WOCS 4540: Detailed Analysis of a very Long Orbital Period Blue Straggler

The Astrophysical Journal, 2023
WOCS 4540 is the longest orbital period ( P _orb = 3030 days) blue straggler star (BSS)—white dwarf (WD) pair in the old open cluster NGC 188. It also contains one of the most luminous BSS in the cluster.
Meng Sun, Robert D. Mathieu
doaj   +1 more source