Semper simplicissimam, fundamentalem solutionem quaere. Si simpliciter explicare non potes, non intellexisti. (R. Feynman)
Astrophotography by GrandpaJunkrat - ----- EM* LkHA 234
Cosmology from my armchair..............................
I do it metric .............................................................. Location:
bastion@protonmail.com The Netherlands
Bortle 7 - 9
Overview and Scientific Classification
WDS 21430+6606 corresponds to EM* LkHα 234, a well‑known Herbig Ae/Be star embedded in the bright reflection nebula NGC 7129. The star is one of the dominant young B‑type sources illuminating the nebula and driving energetic outflows, including Herbig-Haro objects. Its strong emission lines, infrared excess, and association with reflection nebulosity confirm its status as a young, actively accreting intermediate‑mass star. WDS 21430+6606 corresponds to EM LkHα 234, a young Herbig Ae/Be star embedded in the reflection nebula NGC 7129. The primary exhibits strong emission lines, infrared excess, and surrounding reflection nebulosity, consistent with an actively accreting pre‑main‑sequence star.*
Scientific classification
EM* LkHα 234 is classified as a B5Ve Herbig Ae/Be star, showing strong Hα emission, near‑infrared excess, and signatures of circumstellar dust and gas. It is also catalogued as a young stellar object, an emission‑line star, a variable star, and the source of Herbig-Haro flows. The star’s infrared brightness and its detection in IRAS, 2MASS, and other infrared surveys indicate the presence of a substantial circumstellar disk or envelope. The WDS classification lists multiple nearby components, but these are almost certainly optical alignments within the crowded star‑forming region rather than gravitationally bound companions.
Stellar Mass Estimate
As a B5Ve Herbig Ae/Be star, LkHα 234 is expected to have a mass of approximately five to six solar masses. This estimate is consistent with its spectral type, luminosity, and Gaia parallax of roughly 1.14 mas, which places the star at a distance of about 870 to 900 parsecs. Its strong emission lines and infrared excess indicate that it is still contracting toward the main sequence, but the underlying stellar mass is already characteristic of an intermediate‑mass B‑type star.
Age Estimate
LkHα 234 is extremely young, with an estimated age of less than one million years. Its association with Herbig-Haro objects, active accretion, and a dense circumstellar environment all point to an early pre‑main‑sequence evolutionary stage. The star is one of the youngest and most massive members of the NGC 7129 cluster, and its youth is further supported by its strong infrared excess and the presence of a reflection nebula illuminated by the star itself.
Spectral Energy Distribution (SED) Reconstruction
The SED of LkHα 234 shows a bright B‑type photosphere in the optical, with magnitudes such as V ≈ 12.7 and G ≈ 12.36, followed by a steep rise into the near‑infrared, where the star reaches K ≈ 7.08. This dramatic increase in flux reflects strong thermal emission from warm circumstellar dust. The SED is characteristic of a deeply embedded Herbig Ae/Be star with a substantial disk and envelope, showing both reddening at short wavelengths and excess emission at long wavelengths. The combination of optical extinction, infrared excess, and emission‑line activity produces a classic Herbig Ae/Be SED with contributions from both the stellar photosphere and the surrounding dust.
WDS 21430+6606
The WDS listing includes eleven nearby stars (components B–L) that lie close to LkHα 234 in projection. Gaia parallaxes and proper motions show that all of these objects are located at clearly different distances and share no common motion with the primary or with each other. None of the listed components are physically bound to LkHα 234.
The WDS entry therefore represents a purely optical configuration in a crowded and nebulous field, rather than a true multiple stellar system.
