Loading AI tools
K-type giant in Microscopium From Wikipedia, the free encyclopedia
HD 200073 (HR 8046; 43 G. Microscopii) is a solitary star located in the southern constellation Microscopium 8.5′ northwest of Zeta Microscopii. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.94.[2] The object is located relatively close at a distance of 227 light-years based on Gaia DR3 parallax measurements, but it is receding with a heliocentric radial velocity of 39 km/s.[6] At its current distance, HD 200073's brightness is diminished by an interstellar extinction of 0.13 magnitudes[15] and it has an absolute magnitude of +1.79.[7] It has a relatively high proper motion across the celestial sphere, moving at a rate of 213 mas/yr.[1]
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Microscopium |
Right ascension | 21h 02m 27.16546s[1] |
Declination | −38° 31′ 51.4904″[1] |
Apparent magnitude (V) | 5.94[2] |
Characteristics | |
Evolutionary stage | red giant branch[3] |
Spectral type | K2 III[4] or K0 IV[5] |
B−V color index | +1.15[2] |
Astrometry | |
Radial velocity (Rv) | 39±10[6] km/s |
Proper motion (μ) | RA: +156.842 mas/yr[1] Dec.: −171.108 mas/yr[1] |
Parallax (π) | 14.358 ± 0.0466 mas[1] |
Distance | 227.2 ± 0.7 ly (69.6 ± 0.2 pc) |
Absolute magnitude (MV) | +1.79[7] |
Details | |
Mass | 1.03[8] M☉ |
Radius | 9.15±0.46[9] R☉ |
Luminosity | 28.8±0.3[1] L☉ |
Surface gravity (log g) | 2.75[8] cgs |
Temperature | 4,569±50[10] K |
Metallicity [Fe/H] | −0.13[8] dex |
Rotational velocity (v sin i) | 2.7±1.1[11] km/s |
Age | 8.79+2.32 −2.04[12] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 200073 has a stellar classification of K2 III,[4] indicating that it is an evolved K-type giant that has exhausted hydrogen at its core and left the main sequence. Astronomer David Stanley Evans gave a class of K0 IV,[5] indicating that it is a slightly evolved subgiant that is ceasing hydrogen fusion at its core. HD 200073 is currently on the red giant branch,[3] fusing hydrogen in a shell around an inert helium core. It has a comparable mass to the Sun[8] but at the age of 8.79 billion years,[12] it has expanded to 9.15 times the radius of the Sun.[9] It radiates 28.8 times the luminosity of the Sun[1] from its enlarged photosphere at an effective temperature of 4,569 K.[10] HD 200073 is slightly metal-deficient with an iron abundance of [Fe/H] = −0.13 or 74.1% of the Sun's.[8] It spins modestly with a projected rotational velocity of 2.7 km/s.[11]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.