A Slowly Pulsating Run-Away B Star at High Galactic Latitude Ejected From a Spiral Arm

Heber U, Halenke M, Bhat A, Schaffenroth V (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Astronomische Nachrichten Wiley

DOI: 10.1002/asna.70003

Abstract

We report the discovery of the young B6 V run-away star LAMOST J083323.18 + 430825.4, 2.5 kpc above the Galactic plane. Its atmospheric parameters and chemical composition are determined from LAMOST spectra, indicating normal composition. Effective temperature ((Formula presented.) = (Formula presented.) K) and gravity ((Formula presented.) = (Formula presented.)) suggest that the star is close to terminating hydrogen burning. An analysis of the spectral energy distribution allowed us to determine the angular diameter as well as the interstellar reddening. Using evolutionary models from the MIST database we derived the stellar mass ((Formula presented.)) and age ((Formula presented.) Myr). The spectroscopic distance (4.17 kpc), the radius ((Formula presented.)), and the luminosity ((Formula presented.) = (Formula presented.)) then result from the atmospheric parameters. Using Gaia proper motions, the trajectory is traced back to the Galactic disk to identify the place of birth in a spiral arm. The ejection velocity of 92 km s−1 is typical for runaway stars in the halo. The age of the star is larger than its time of flight ((Formula presented.) Myr), which favors a binary supernova event as the likely ejection mechanism. The TESS light curve shows variations with a period of 3.58 days from which we conclude that it is a slowly pulsating B-star, one of very few run-away B-stars known to pulsate.

Authors with CRIS profile

Ulrich Heber Professur für Astronomie und Astrophysik

Involved external institutions

Universität Potsdam DE Germany (DE) Thüringer Landessternwarte Tautenburg (TLS) - Karl-Schwarzschild-Observatorium DE Germany (DE)

How to cite

APA:

Heber, U., Halenke, M., Bhat, A., & Schaffenroth, V. (2025). A Slowly Pulsating Run-Away B Star at High Galactic Latitude Ejected From a Spiral Arm. Astronomische Nachrichten. https://doi.org/10.1002/asna.70003

MLA:

Heber, Ulrich, et al. "A Slowly Pulsating Run-Away B Star at High Galactic Latitude Ejected From a Spiral Arm." Astronomische Nachrichten (2025).

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