Two New Rapidly Rotating ON Stars Found with LAMOST

The ON stars are a rare subtype of O stars of uncertain origin. We report two new, rapidly rotating ON stars found in data acquired with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. LS I +61 28 is an ON8.5 Vn dwarf with a projected equatorial rotational velocity of , while HDE 2366...

Full description

Saved in:
Bibliographic Details
Published inThe Astrophysical journal Vol. 888; no. 2; pp. 81 - 86
Main Authors Li, Guang-Wei, Howarth, Ian D.
Format Journal Article
LanguageEnglish
Published Philadelphia The American Astronomical Society 10.01.2020
IOP Publishing
Subjects
Astrophysics
Data acquisition
Equator
Inclination angle
Kinematics
Luminosity
O stars
Spectroscopic telescopes
Stellar rotation
Velocity
Online AccessGet full text

Cover

More Information
Summary:The ON stars are a rare subtype of O stars of uncertain origin. We report two new, rapidly rotating ON stars found in data acquired with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. LS I +61 28 is an ON8.5 Vn dwarf with a projected equatorial rotational velocity of , while HDE 236672 is an ON9 IVn subgiant with . The former is the first rapidly rotating ON dwarf to be found, and the latter is only the third ON subgiant. The luminosity classes of non-supergiant ON stars appear to be influenced by the axial inclination angle i: the rapidly rotating giants are close to equator-on, while ON dwarfs with lower values are viewed more nearly pole-on. Combining parallaxes and proper motions from Gaia Data Release 2 with radial-velocity measurements, we investigate the kinematics of non-supergiant ON stars and infer that the dynamics, rapid rotation, and surface nitrogen characteristics may all be consequences of binary interaction.
Bibliography:AAS21008
Stars and Stellar Physics
ISSN:0004-637X
1538-4357
DOI:10.3847/1538-4357/ab5b01