A DOUBLE MAIN SEQUENCE IN THE GLOBULAR CLUSTER NGC 6397

被引：90

作者：

Milone, A. P. ^{[1
,2
]}

Marino, A. F. ^{[3
]}

Piotto, G. ^{[4
,5
]}

Bedin, L. R. ^{[6
]}

Anderson, J. ^{[6
]}

Aparicio, A. ^{[1
,2
]}

Cassisi, S. ^{[7
]}

Rich, R. M. ^{[8
]}

机构：

[1] Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain

[2] Univ La Laguna, Dept Astrophys, E-38200 San Cristobal la Laguna, Tenerife, Spain

[3] Max Planck Inst Astrophys, D-85741 Garching, Germany

[4] Univ Padua, Dipartimento Astron, I-35122 Padua, Italy

[5] INAF Osservatorio Astron Padova, I-35122 Padua, Italy

[6] Space Telescope Sci Inst, Baltimore, MD 21218 USA

[7] INAF Osservatorio Astron Collurania, I-64100 Teramo, Italy

[8] Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA

来源：

ASTROPHYSICAL JOURNAL | 2012年 / 745卷 / 01期

关键词：

globular clusters: individual (NGC 6397); stars: Population II; MULTIPLE STELLAR POPULATIONS; ADVANCED CAMERA; OMEGA-CENTAURI; GIANT STARS; ACS SURVEY; ABUNDANCES; NGC-6397; BRANCH; ASTROMETRY; NGC-2808;

D O I：

10.1088/0004-637X/745/1/27

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

High-precision multi-band Hubble Space Telescope (HST) photometry reveals that the main sequence of the globular cluster NGC 6397 splits into two components, containing similar to 30% and similar to 70% of the stars. This double sequence is consistent with the idea that the cluster hosts two stellar populations: (1) a primordial population that has a composition similar to field stars, containing similar to 30% of the stars, and (2) a second generation with enhanced sodium and nitrogen, depleted carbon and oxygen, and a slightly enhanced helium abundance (Delta Y similar to 0.01). We examine the color difference between the two sequences across a variety of color baselines and find that the second sequence is anomalously faint in m(F336W). Theoretical isochrones indicate that this could be due to NH depletion.

引用

页数：10

共 50 条

[41] Lithium in the globular cluster NGC 6397 Evidence for dependence on evolutionary status
Hernandez, J. I. Gonzalez
Bonifacio, P.
Caffau, E.
Steffen, M.
Ludwig, H. -G.
Behara, N. T.
Sbordone, L.
Cayrel, R.
Zaggia, S.
ASTRONOMY & ASTROPHYSICS, 2009, 505 (02) : L13 - U6
[42] Two contact binaries at different evolutionary stages in the globular cluster NGC 6397
Li, K.
Qian, S. -B.
NEW ASTRONOMY, 2013, 25 : 12 - 18
[43] AN APPLICATION OF CCD UVBY PHOTOMETRY TO THE GLOBULAR-CLUSTER NGC-6397
ANTHONYTWAROG, BJ
ASTRONOMICAL JOURNAL, 1987, 93 (06): : 1454 - &
[44] THE PHYSICS OF CRYSTALLIZATION FROM GLOBULAR CLUSTER WHITE DWARF STARS IN NGC 6397
Winget, D. E.
Kepler, S. O.
Campos, Fabiola
Montgomery, M. H.
Girardi, Leo
Bergeron, P.
Williams, Kurtis
ASTROPHYSICAL JOURNAL LETTERS, 2009, 693 (01) : L6 - L10
[45] The Luminosity Function of the Globular Cluster NGC 6397 Near the Limit of Hydrogen Burning
King, I. R.
Anderson, J.
Cook, A. M.
Piotto, G.
Astrophysical Journal, 492 (02):
[46] OPTICAL STRUCTURE OF THE CORE OF THE DYNAMICALLY ADVANCED GLOBULAR-CLUSTER NGC 6397
AURIERE, M
ASTRONOMY & ASTROPHYSICS, 1982, 109 (02) : 301 - 304
[47] Massive, collisionally produced Blue Stragglers in the galactic globular cluster NGC 6397
Saffer, RA
Sepinsky, JF
DeMarchi, G
Livio, M
Paresce, F
Shara, M
Zurek, D
STELLAR COLLISIONS, MERGERS, AND THEIR CONSEQUENCES, 2002, 263 : 157 - 162
[48] The luminosity function of the globular cluster NGC 6397 near the limit of hydrogen burning
King, IR
Anderson, J
Cool, AM
Piotto, G
ASTROPHYSICAL JOURNAL, 1998, 492 (01): : L37 - L40
[49] Cataclysmic variables and a candidate helium white dwarf in the globular cluster NGC 6397
Edmonds, PD
Grindlay, JE
Cool, A
Cohn, H
Lugger, P
Bailyn, C
ASTROPHYSICAL JOURNAL, 1999, 516 (01): : 250 - 262
[50] MAIN-SEQUENCE CCD PHOTOMETRY OF THE GLOBULAR-CLUSTER NGC-362
BOLTE, M
ASTROPHYSICAL JOURNAL, 1987, 315 (02): : 469 - 479

← 1 2 3 4 5 →