Zobrazeno 1 - 10
of 72
pro vyhledávání: '"Barbara J. Anthony-Twarog"'
Autor:
Barbara J. Anthony-Twarog, Constantine P. Deliyannis, Aaron Steinhauer, Qinghui Sun, Bruce A. Twarog
Publikováno v:
The Astronomical Journal, Vol 168, Iss 3, p 103 (2024)
We have analyzed high-dispersion spectra in the Li 6708 Å region for 167 stars within the anticenter cluster NGC 2204. From 105 probable members, abundance analysis of 45 evolved stars produces [Fe/H] = −0.40 ± 0.12, [Si/Fe] = 0.14 ± 0.12, [Ca/F
Externí odkaz:
https://doaj.org/article/89ac29713cb44467ac3ece163e028312
Autor:
Qinghui Sun, Constantine P. Deliyannis, Aaron Steinhauer, Barbara J. Anthony-Twarog, Bruce A. Twarog
Publikováno v:
The Astrophysical Journal, Vol 952, Iss 1, p 71 (2023)
We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420 Myr old open cluster M48 and report lithium detections or upper limits for 234 members and likely members. The 171 single members define a number of notable Li-mass trends
Externí odkaz:
https://doaj.org/article/3b6800b6e78f440fa044c753ba297256
Publikováno v:
The Astronomical Journal, Vol 165, Iss 3, p 105 (2023)
Precision CCD uvbyCa H β photometry is presented of the old cluster, M67, covering one square degree with typical internal precision at the 0.005–0.020 mag level to V ∼ 17. The photometry is calibrated using standards over a wide range in lumino
Externí odkaz:
https://doaj.org/article/d01b8fe4e4f0437ab3c9b51468fcc12b
Autor:
Qinghui Sun, Constantine P Deliyannis, Bruce A Twarog, Barbara J Anthony-Twarog, Jeffrey D Cummings, Aaron Steinhauer
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 513:5387-5406
We present WIYN/Hydra spectra of 34 red giant candidate members of NGC 188, which, together with WOCS and Gaia data yield 23 single members, 6 binary members, 4 single nonmembers, and 1 binary nonmember. We report [Fe/H] for 29 members and derive [Fe
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2fe150389f8940213e9d71104ab38597
https://doi.org/10.1093/mnras/stac1251
https://doi.org/10.1093/mnras/stac1251
High-dispersion spectra for giants through turnoff stars in the Li 6708 Angstrom region have been obtained and analyzed in the old, metal-deficient open cluster, NGC 2243. When combined with high dispersion data from other surveys, the cluster is fou
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c95fef2561062d927e00c2ef5fc6332b
http://arxiv.org/abs/2006.10862
http://arxiv.org/abs/2006.10862
Publikováno v:
The Astronomical Journal. 161:159
High-dispersion spectra in the Li 6708 Angstrom region have been obtained and analyzed in the old, metal-deficient cluster, NGC 2243. From Hydra spectra for 29 astrometric and radial-velocity members, we derive rotational velocities, as well as [Fe/H
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::146d61b5772f8f3030b45563b6384bf8
https://doi.org/10.3847/1538-3881/abe0b7
https://doi.org/10.3847/1538-3881/abe0b7
Autor:
A. Steinhauer, Qinghui Sun, Constantine P. Deliyannis, Bruce A. Twarog, Barbara J. Anthony-Twarog
Publikováno v:
The Astronomical Journal. 159:246
We present $UBVRI$ photometry of 8702 stars in a $0.5 ^\circ\times0.5 ^\circ$ field in the direction of NGC 7142, taken with the Half Degree Imager (HDI) at the WIYN 0.9-meter telescope, to improve knowledge of this cluster's basic parameters. Our ph
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b65e2958fc5e00f08c58dc4de2679e3d
https://doi.org/10.3847/1538-3881/ab8814
https://doi.org/10.3847/1538-3881/ab8814
Autor:
Bruce A. Twarog, Dianne Harmer, Donald B. Lee-Brown, A. Steinhauer, Qinghui Sun, Constantine P. Deliyannis, Barbara J. Anthony-Twarog
Hydra spectra of 85 G-K dwarfs in the young cluster, M35, near the Li 6708 Angstrom line region are analyzed. From velocities and Gaia astrometry, 78 are likely single-star members which, combined with previous work, produces 108 members with T_eff r
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::23a1e64bd28ea52ce773b852ed335a30
HYDRA spectra of 287 stars in the field of NGC 2506 from the turnoff through the giant branch are analyzed. With previous data, 22 are identified as probable binaries; 90 more are classified as potential non-members. Spectroscopic analyses of ~60 red
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0f8fa27e77c039ff2954b3b9d0e992f9
Autor:
Pierre Bastien, Eugene F. Milone, John Menzies, Allyn Smith, Alistair R. Walker, Saul Adelman, Jens Knude, Wen Ping Chen, Kevin Volk, Steve B. Howell, Antonio Mario Magalhães, D. W. Kurtz, Barbara J. Anthony-Twarog
Publikováno v:
Proceedings of the International Astronomical Union. 11:159-170
Commission 25 (C25) deals with the techniques and issues involved with the measurement of optical and infrared radiation intensities and polarization from astronomical sources. As such, in recent years attention has focused on photometric standard st
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3a7331b1a24d03c7057fb277c804fc89
https://doi.org/10.1017/s1743921316000727
https://doi.org/10.1017/s1743921316000727