A transitional pre-main-sequence object in the F-type gap

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Authors: H.N. van Roon
Cited by: 0

Abstract

Stars in the 6000–7000 K regime occupy the poorly sampled “F-type pre-main-sequence gap”, where magnetic coupling, rotation, and disk dispersal undergo rapid transitions. Survey pipelines often misclassify such objects due to their intermediate and rapidly evolving properties. We report the identification of a transitional pre-main-sequence object, TYC 4471-627-1 (Gaia DR3 2224495886248313088), located in the Cepheus Flare extinction wall. Its properties challenge the assumption of discrete evolutionary categories between T Tauri stars and Herbig Ae stars. We combine Gaia DR3 astrometry and low-resolution spectroscopy with NEOWISE mid-infrared photometry to assess the stellar parameters, rotation, and circumstellar environment. The data quality is excellent (RUWE = 0.97; astrometric excess noise ≈ 0), ensuring a reliable distance of ~156 pc. The object exhibits a high projected rotational velocity (v sin i = 45.78 km/s), inconsistent with a mature F-type field star. Its mid-infrared spectral energy distribution is remarkably flat from 3.4–12 μm, indicating the presence of a warm, optically thick disk. TYC 4471-627-1 appears to be an intermediate-mass T Tauri / Herbig Ae transitional object embedded in a compact extinction structure. Its combined rotation and infrared properties suggest a continuous, rather than discrete, evolutionary state.

Fields of Study & Subjects

Astrophysics and Star Formation Studies Stellar planetary and galactic studies Astronomy and Astrophysical Research

Publication details

Journal / source
Zenodo (CERN European Organization for Nuclear Research)
Publication date
16 January 2026
Language
EN