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Rho Persei

Rho Persei
Diagram showing star positions and boundaries of the Perseus constellation and its surroundings
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Location of ρ Persei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 05m 10.59385s
Declination +38° 50′ 24.9943″
Apparent magnitude (V) +3.39
Characteristics
Spectral type M4 II
U−B color index +1.79
B−V color index +1.65
Variable type Semiregular
Astrometry
Radial velocity (Rv) +29.10 ± 0.30 km/s
Proper motion (μ) RA: +129.22 mas/yr
Dec.: –105.70 mas/yr
Parallax (π) 10.60 ± 0.25mas
Distance 308 ± 7 ly
(94 ± 2 pc)
Absolute magnitude (MV) –1.7
Details
Mass 5.0 M
Radius 150 R
Luminosity 2,290 L
Surface gravity (log g) 1.0 cgs
Temperature 4,111 K
Rotational velocity (v sin i) 11.2 km/s
Age 4.4 × 108 years
Other designations
Gorgonea Tertia, ρ Persei, 25 Per, BD+38°630, FK5 109, GC 3682, HD 19058, HIP 14354, HR 921, PPM 68074, SAO 56138.
Database references
SIMBAD data

Rho Persei (Rho Per, ρ Persei, ρ Per) is a star in the northern constellation of Perseus. It has the traditional name Gorgonea Tertia, being the third member of the quartet called the Gorgonea in reference to the Gorgons from the legend of Perseus. An apparent visual magnitude of +3.39 makes it visible to the naked eye, but a challenge to view from a well-lit urban environment. Based upon parallax measurements, it is located at a distance of roughly 308 light-years (94 pc) from Earth.

Rho Persei is a semiregular variable star of the μ Cephei type, whose apparent magnitude varies between 3.3 and 4.0 with periods of 50, 120 and 250 days. The star has reached the asymptotic giant branch of its evolution. It is near the tip of the red giant branch with a stellar classification of M4 II. The outer envelope has an effective temperature of 4,111 K, giving it the red-orange hue of an M-type star.

This star has a mass five times the mass of the Sun, while its radius has expanded to 150 times solar. It is radiating some 2,290 times the Sun's luminosity. Rho Persei is losing mass at the rate of 1.2 × 10−8 solar masses per year, or the equivalent of the Sun's mass every 83 million years. It is about 440 million years in age.


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Wikipedia

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