Results 1 to 10 of about 485,760 (336)
Rotation of Horizontal‐Branch Stars in Globular Clusters [PDF]
The Astrophysical Journal, 2000 The rotation of horizontal branch stars places important constraints on angular momentum evolution in evolved stars and therefore rotational mixing on the giant branch. Prompted by new observations of rotation rates of horizontal branch stars, we calculate simple models for the angular momentum evolution of a globular cluster giant star from the base ...
Alison Sills, Marc H. Pinsonneault
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Multimodal Distributions along the Horizontal Branch [PDF]
The Astrophysical Journal, 1998 We report on HST/WFPC2 U,V and far-ultraviolet observations of two Galactic Globular Clusters (GGCs), NGC 6205 = M13 and NGC 6093 = M80. Both of these clusters have horizontal-branch (HB) tails that extend to the helium-burning main sequence, with the hottest stars reaching theoretical effective temperatures above 35,000 K.
F. R. Ferraro +4 more
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Precision CCD Photometry of the Horizontal Branch [PDF]
Symposium - International Astronomical Union, 1995 The Strömgren four-color system is well suited to the measure and analysis of horizontal-branch stars. The increased accuracy of the CCD photometric system and the ability to measure fainter stars in very crowded regions make the combination of the CCD system and four-color photometry an excellent one to study horizontal-branch stars in globular ...
A. G. D. Philip
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Horizontal Branch Stellar Evolution
, 1995 I review aspects of the evolution of horizontal branch (HB) stars. I start by discussing current topics in the study of HB stellar evolution, including a brief review of the main determinants of the structure of low-mass core helium burning stars and of HB morphology.
Ben Dorman
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Rotation, planets, and the 'second parameter' of the horizontal branch [PDF]
Monthly Notices of the Royal Astronomical Society, 2000 We analyze the angular momentum evolution from the red giant branch (RGB) to the horizontal branch (HB) and along the HB. Using rotation velocities for stars in the globular cluster M13, we find that the required angular momentum for the fast rotators is up to 1-3 orders of magnitude (depending on some assumptions) larger than that of the sun.
Noam Soker, Amos Harpaz
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Mass Loss on the Horizontal Branch: An Application to NGC 6791 [PDF]
The Astrophysical Journal, 2000 The presence of a substantial number of hot stars in the extremely metal-rich} open cluster NGC6791 has been a mystery. If these hot stars are in their core helium burning phase, they are significantly bluer (hotter) than predicted by canonical stellar evolution theory. No obvious explanation is available yet.
H. Yong, P. Demarque, Sukyoung K. Yi
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Meikuang Anquan, 2021 This paper takes the multi-branch horizontal grouting well reinforced with limestone on the corresponding floor L8 in the 15011 coal seam working face of Zhaogu No.1 Mine as the research object.
LIU Xiugang +3 more
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Identification of Blue Horizontal-branch Stars from LAMOST DR5
The Astrophysical Journal Supplement Series, 2023 We construct a new catalog of the blue horizontal-branch (BHB) stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR5 data set, which contains 5355 + 81 BHB stars at high Galactic latitude (∣Glat∣ > 20°).
Jie Ju +8 more
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Horizontal Branch Evolution [PDF]
International Astronomical Union Colloquium, 1989 AbstractIn 1973 the outstanding problems confronting the theory of horizontal branch evolution were the “second parameter” problem and the Oosterhoff Effect. Despite significant progress, particularly in the observations and in the observation/theory interface, they remain as the outstanding problems of 1988.
R.T. Rood, D.A. Crocker
openaire +2 more sources
The horizontal-branch A stars [PDF]
Publications of the Astronomical Society of the Pacific, 1979 The observational determination of astrophysical parameters of horizontal-branch A stars is discussed. Effective temperatures, surface gravities, and bolometric magnitudes are determined for seven field horizontal-branch A stars, and their masses are calculated. The mean mass for these seven stars is 0.6 + or - 0.4 solar mass.
A. G. D. Philip, D. S. Hayes
openaire +2 more sources