Abstract
M12 is the prototypical collapsed-core globular cluster. Having undergone collapse, its core is believed now to be expanding, with energy for the re-expansion provided by binary stars, which turn gravitational potential energy into kinetic energy. Because these binary stars are generally more massive than single stars, they will have settled to the centre of the cluster. We report here that several of the stars at the core of M15 show Ca II H- and K-line emission characteristic of young, rapidly rotating stars and close binaries. We argue that the emission from M15 comes from primordial binaries, in which a period of spin-up has led to magnetic field generation by enhanced dynamo action, which in turn causes heating of the stellar chromospheres. If this interpretation is correct, the Ca H and K emission may provide an important diagnostic tool of the binary population in cluster cores, and thus of the cluster dynamics. (author).
Murphy, B W;
[1]
Rutten, R G.M.;
[2]
Callanan, P J;
[3]
Seitzer, Patrick;
[4]
Charles, P A;
[5]
Cohn, H N;
Lugger, P M
[6]
- Rijksuniversiteit Utrecht (Netherlands). Inst. of Astronomy
- Astronomical Inst. 'Anton Pannekoek', Amsterdam (Netherlands)
- Oxford Univ. (UK). Dept. of Astrophysics
- Space Telescope Science Inst., Baltimore, MD (USA)
- Oxford Univ. (UK). Dept. of Astrophysics Observatorio del Roque do los Muchachos, Santa Cruz de La Palma, Tenerife, Canary Islands (Spain)
- Indiana Univ., Bloomington, IN (USA). Dept. of Astronomy
Citation Formats
Murphy, B W, Rutten, R G.M., Callanan, P J, Seitzer, Patrick, Charles, P A, Cohn, H N, and Lugger, P M.
Detection of binaries in the core of the globular cluster M15 using calcium emission lines.
United Kingdom: N. p.,
1991.
Web.
doi:10.1038/351130a0.
Murphy, B W, Rutten, R G.M., Callanan, P J, Seitzer, Patrick, Charles, P A, Cohn, H N, & Lugger, P M.
Detection of binaries in the core of the globular cluster M15 using calcium emission lines.
United Kingdom.
https://doi.org/10.1038/351130a0
Murphy, B W, Rutten, R G.M., Callanan, P J, Seitzer, Patrick, Charles, P A, Cohn, H N, and Lugger, P M.
1991.
"Detection of binaries in the core of the globular cluster M15 using calcium emission lines."
United Kingdom.
https://doi.org/10.1038/351130a0.
@misc{etde_5378278,
title = {Detection of binaries in the core of the globular cluster M15 using calcium emission lines}
author = {Murphy, B W, Rutten, R G.M., Callanan, P J, Seitzer, Patrick, Charles, P A, Cohn, H N, and Lugger, P M}
abstractNote = {M12 is the prototypical collapsed-core globular cluster. Having undergone collapse, its core is believed now to be expanding, with energy for the re-expansion provided by binary stars, which turn gravitational potential energy into kinetic energy. Because these binary stars are generally more massive than single stars, they will have settled to the centre of the cluster. We report here that several of the stars at the core of M15 show Ca II H- and K-line emission characteristic of young, rapidly rotating stars and close binaries. We argue that the emission from M15 comes from primordial binaries, in which a period of spin-up has led to magnetic field generation by enhanced dynamo action, which in turn causes heating of the stellar chromospheres. If this interpretation is correct, the Ca H and K emission may provide an important diagnostic tool of the binary population in cluster cores, and thus of the cluster dynamics. (author).}
doi = {10.1038/351130a0}
journal = []
volume = {351:6322}
journal type = {AC}
place = {United Kingdom}
year = {1991}
month = {May}
}
title = {Detection of binaries in the core of the globular cluster M15 using calcium emission lines}
author = {Murphy, B W, Rutten, R G.M., Callanan, P J, Seitzer, Patrick, Charles, P A, Cohn, H N, and Lugger, P M}
abstractNote = {M12 is the prototypical collapsed-core globular cluster. Having undergone collapse, its core is believed now to be expanding, with energy for the re-expansion provided by binary stars, which turn gravitational potential energy into kinetic energy. Because these binary stars are generally more massive than single stars, they will have settled to the centre of the cluster. We report here that several of the stars at the core of M15 show Ca II H- and K-line emission characteristic of young, rapidly rotating stars and close binaries. We argue that the emission from M15 comes from primordial binaries, in which a period of spin-up has led to magnetic field generation by enhanced dynamo action, which in turn causes heating of the stellar chromospheres. If this interpretation is correct, the Ca H and K emission may provide an important diagnostic tool of the binary population in cluster cores, and thus of the cluster dynamics. (author).}
doi = {10.1038/351130a0}
journal = []
volume = {351:6322}
journal type = {AC}
place = {United Kingdom}
year = {1991}
month = {May}
}