Delta Piscium

Delta Piscium (δ Piscium) is a solitary,^[8] orange-hued star in the zodiac constellation of Pisces. It has an apparent visual magnitude of +4.4,^[2] so it is bright enough to be faintly visible to the naked eye. Based upon an annual parallax shift of 10.86 mas, it is around 300 light-years (92 parsecs) from the Sun.^[1] The visual magnitude of the star is diminished by an interstellar absorption factor of 0.08 due to interstellar dust.^[9]

Delta Piscium

Location of δ Piscium (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Pisces
Right ascension	00h 48m 40.9443s[1]
Declination	+07° 35′ 06.295″[1]
Apparent magnitude (V)	+4.416[2]
Characteristics
Spectral type	K4 IIIb[3]
U−B color index	+1.831[2]
B−V color index	+1.500[2]
Astrometry
Radial velocity (Rv)	+32.45±0.18[4] km/s
Proper motion (μ)	RA: +81.994 mas/yr[1] Dec.: −50.232 mas/yr[1]
Parallax (π)	10.8577±0.1787 mas[1]
Distance	300 ± 5 ly (92 ± 2 pc)
Absolute magnitude (MV)	−0.46[5]
Details
Mass	1.65[3] M☉
Radius	38.01+0.71 −0.73[6] R☉
Luminosity	291.7±13.3[6] L☉
Surface gravity (log g)	1.88[1] cgs
Temperature	3868±35[6] K
Metallicity [Fe/H]	−0.19[1] dex
Rotational velocity (v sin i)	5.5[4] km/s
Age	2.98[3] Gyr
Other designations
δ Psc, 63 Piscium, BD+06°107, FK5 28, HD 4656, HIP 3786, HR 224, SAO 109474, WDS J00487+0735A[7]
Database references
SIMBAD	data

This is an evolved K-type giant star with a stellar classification of K4 IIIb.^[3] It has around 1.65 times the mass of the Sun and, at the age of three billion years,^[3] has expanded to 38^[6] times the Sun's radius. The star is radiating 292 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,868 K.^[6]

Because Delta Piscium is positioned near the ecliptic, so it is subject to lunar occultations.^[10] It has a magnitude 13.99 visual companion at an angular separation of 135.0 arc seconds on a position angle of 12°, as of 2011.^[11]

Naming

In Chinese, 外屏 (Wài Píng), meaning Outer Fence, refers to an asterism of stars, δ Piscium, ε Piscium, ζ Piscium, μ Piscium, ν Piscium, ξ Piscium and α Piscium. Consequently, the Chinese name for δ Piscium itself is 外屏一 (Wài Píng yī, English: the First Star of Outer Fence.)^[12]