Results 41 to 50 of about 3,864 (175)

Follow-up observations of pulsating subdwarf B stars: Multisite campaigns on PG 1618+563B and PG 0048+091

, 2007
We present follow-up observations of pulsating subdwarf B (sdB) stars as part of our efforts to resolve the pulsation spectra for use in asteroseismological analyses.
A.‐Y. Zhou, C. Akan, C.‐W. Chen, Chaplin W. J., D. An, D. Kilkenny, D. M. Terndrup, G. A. Gelven, G. W. Wolf, H. Worters, H.‐C. Lin, Heber U., J. R. Eggen, Kawaler S., M. D. Reed, M. Siwak, O. Cakirli, S. J. O’Toole, S. L. Harms, S. Zola, Seung‐Lee Kim, Silvotti R., W. P. Chen   +22 more
core   +1 more source

ε-mechanism driven pulsations in hot subdwarf stars with mixed H-He atmospheres [PDF]

, 2017
The ε mechanism is a self-excitation mechanism of stellar pulsations which acts in regions where nuclear burning takes place. It has been shown that the ε mechanism can excite pulsations in hot pre-horizontal branch stars before they settle into the ...
Althaus, Leandro Gabriel, Battich, Tiara, Corsico, Alejandro Hugo, Miller Bertolami, Marcelo Miguel   +3 more
core   +2 more sources

LS IV — 14°116 : A Time-Resolved Spectroscopic Study

Open Astronomy, 2017
LSIV-14 116 is a very unusual subdwarf B star. It pulsates non-radially with high-order g-modes, these pulsations are unexpected and unexplained, as the effective temperature is 6 000K hotter than the blue edge of the hot subdwarf g-mode instability ...
Martin Pamela, Jeffery C. Simon
doaj   +1 more source

The fastest unbound star in our Galaxy ejected by a thermonuclear supernova [PDF]

, 2015
Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star.
Burgett, W. S., Chambers, K., Flewelling, H., Fürst, F., Geier, S., Han, Z., Heber, U., Irrgang, A., Kaiser, N., Kotak, R., Kupfer, T., Levitan, D., Liu, Z., Magnier, E., Sesar, B., Smith, K., Wainscoat, R., Wang, B., Waters, C., Ziegerer, E.   +19 more
core   +2 more sources

Asteroseismic Analysis of Pulsating Subdwarf B Stars [PDF]

International Astronomical Union Colloquium, 2002
AbstractWe briefly present a method to perform detailed asteroseismological analyses of pulsating subdwarf B (sdB) stars (also referred to as the EC14026 stars). We use a forward approach based on the computation of large grids of sdB stellar models (each model being analyzed with a linear nonadiabatic pulsation code) to derive, in an objective way ...
S. Charpinet, G. Fontaine, P. Brassard
openaire   +1 more source

Rotation in sdB stars as revealed by stellar oscillations

Open Astronomy, 2018
An interesting opportunity offered by the detection of stellar oscillations is the possibility to infer the internal rotation rate of a star through the so-called rotational splittings. Such seismic measurements remained rather scarce for hot B subdwarf (
Charpinet Stephane, Giammichele Noemi, Zong Weikai, Van Grootel Valérie, Brassard Pierre, Fontaine Gilles   +5 more
doaj   +1 more source

The empirical mass distribution of hot B subdwarfs: Implications for stellar evolution theory

EPJ Web of Conferences, 2013
Subdwarf B (sdB) stars are hot, compact, and evolved objects that form the very hot end of the horizontal branch, the so-called Extreme Horizontal Branch (EHB).
Green E.M., Brassard P., Charpinet S., Fontaine G., Van Grootel V.   +4 more
doaj   +1 more source

Why do hot subdwarf stars pulsate?

, 2015
Hot subdwarf B stars (sdBs) are the stripped cores of red giants located at the bluest extension of the horizontal branch. Several different kinds of pulsators are found among those stars.
Geier, S.
core   +1 more source

Hot subdwarfs from the ESO Supernova Ia Progenitor Survey: II. Atmospheric parameters of subdwarf O stars [PDF]

, 2006
We address the origin and evolutionary status of hot subdwarf stars by studying the optical spectral properties of 58 subdwarf O (sdO) stars. Combining them with the results of our previously studied subdwarf B (sdB) stars, we aim at investigating ...
A. Stroeer, Ahmad, Baschek, Brown, Charpinet, Christlieb, D'Cruz, D. Reimers, Deetjen, Dorman, Dreizler, Driebe, Driebe, Edelmann, Ferguson, Geier, Green, Greenstein, Groth, Haas, Han, Heber, Heber, Hummer, Jeffery, Koester, Lanz, Lisker, Lisker, Maxted, Maxted, McCook, Moehler, Moehler, N. Christlieb, Napiwotzki, Napiwotzki, Napiwotzki, Ochsenbein, Paczynski, R. Napiwotzki, S. Dreizler, Schlegel, Schönberner, Schönberner, Skrutskie, Smith, Stark, Stys, Sweigart, T. Lisker, Thejll, U. Heber, Werner, Werner, Wisotzki, Østensen   +56 more
core   +2 more sources

Deep Learning–driven Atmospheric Parameter Prediction for Hot Subdwarf Stars with Synthetic and Observed Spectra

The Astrophysical Journal Supplement Series
We design a convolutional neural network incorporating channel attention and spatial attention mechanisms to predict atmospheric parameters of hot subdwarfs.
Zhenxin Lei, Yangyang Dong, Bokai Kou, Mengqi Feng, Ke Hu, Yude Bu, Jingkun Zhao   +6 more
doaj   +1 more source