HD 203030

HD 203030

HD 203030 and its companion (white arrow) with Spitzer IRAC.
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Vulpecula
Right ascension 21h 18m 58.220s
Declination +26° 13 49.96
Apparent magnitude (V) 8.45
Characteristics
Evolutionary stage main sequence
Spectral type K0V
B−V color index 0.750±0.015
Variable type BY Dra
Astrometry
Radial velocity (Rv)−16.92±0.26 km/s
Proper motion (μ) RA: 133.593±0.108 mas/yr
Dec.: 9.563±0.11 mas/yr
Parallax (π)25.4488±0.0610 mas
Distance128.2 ± 0.3 ly
(39.29 ± 0.09 pc)
Absolute magnitude (MV)5.436±0.030
Details
Mass0.965±0.035 M
Radius0.86+0.02
0.03
 R
Luminosity0.593±0.002 L
Surface gravity (log g)4.64+0.03
−0.01
 cgs
Temperature5,603+10
−8
 K
Metallicity [Fe/H]0.06±0.07 dex
0.30+0.02
−0.01
 dex
Rotational velocity (v sin i)5.62+0.13
−0.14
 km/s
Age100+50
70
 Myr
Other designations
V457 Vul, Gaia DR2 1846882224145757056, HD 203030, HIP 105232, WDS 21190+2614, LTT 4041, TYC 2190-1095-1, 2MASS J21185820+2613500
Database references
SIMBADdata
Exoplanet Archivedata

HD 203030, also known as V457 Vulpeculae, is a single, yellow-orange hued star with a sub-stellar companion in the northern constellation of Vulpecula. The designation HD 203030 is from the Henry Draper Catalogue, which is based on spectral classifications made between 1911 and 1915 by Annie Jump Cannon and her co-workers, and was published between 1918 and 1924. This star is invisible to the naked eye, having an apparent visual magnitude of 8.45. It is located at a distance of 128 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −17 km/s.

The stellar classification of HD 203030 is K0V, indicating this is a K-type main-sequence star. It is likely very young, belonging to the 45 million years old IC 2391 open cluster. Based on photometric measurements by Hipparcos, it was found to exhibit low amplitude periodic variability with a range of 0.0139 in magnitude and a period of 4.14 days. However the General Catalog of Variable Stars lists its period as 6.664 days. It is now classified as a chromospherically active BY Draconis variable. The star has 97% of the mass of the Sun and 86% of the Sun's radius. It is radiating 59% of the luminosity of the Sun from its photosphere at an effective temperature of 5,603 K.