Rho Persei


ρ Persei
Perseus constellation map.svg
Red circle.svg
Location of ρ Persei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 05m 10.59385s[1]
Declination +38° 50′ 24.9943″[1]
Apparent magnitude (V) +3.39[2]
Evolutionary stage asymptotic giant branch[3]
Spectral type M4 II[4]
U−B color index +1.79[2]
B−V color index +1.65[2]
Variable type SRb[4]
Radial velocity (Rv)+29.10±0.30[5] km/s
Proper motion (μ) RA: +129.22[1] mas/yr
Dec.: –105.70[1] mas/yr
Parallax (π)10.60 ± 0.25[1] mas
Distance308 ± 7 ly
(94 ± 2 pc)
Absolute magnitude (MV)–1.7[6]
Mass1.9±0.7 M
Radius143±12 R
Surface gravity (log g)0.37±0.15 cgs
Temperature3,479±125 K
Metallicity [Fe/H]−0.15 dex
Rotational velocity (v sin i)11.2[8] km/s
Age440[9] Myr
Other designations
Gorgonea Tertia, Rho Per, ρ Per, 25 Per, BD+38°630, FK5 109, GC 3682, HD 19058, HIP 14354, HR 921, SAO 56138, PPM 68074[10]
Database references

Rho Persei, Latinized from ρ Persei, is a star in the northern constellation of Perseus. It has the traditional name Gorgonea Tertia /ɡɔːrɡəˈnə ˈtɜːrʃə/,[11] being the third member of the quartet called the Gorgonea in reference to the Gorgons from the legend of Perseus.[9] An apparent visual magnitude of +3.39[2] 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.[1]

Rho Persei is a semiregular variable star, whose apparent magnitude varies between 3.3 and 4.0[12] with periods of 50, 120 and 250 days.[6] The star has reached the asymptotic giant branch of its evolution.[3] It is a bright giant star with a stellar classification of M4 II.[4] The outer envelope has an effective temperature of 3,479 K,[7] giving it the red-orange hue of an M-type star.[13]

This star has a mass 1.9 times the mass of the Sun, while its radius has expanded to 143 times solar. It is radiating some 2,700 times the Sun's luminosity.[7] 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.[14] It is about 440 million years in age.[9]


In Chinese, 大陵 (Dà Líng), meaning Mausoleum, refers to an asterism consisting of ρ Persei, 9 Persei, τ Persei, ι Persei, κ Persei, β Persei, 16 Persei and 12 Persei. Consequently, the Chinese name for ρ Persei itself is 大陵六 (Dà Líng liù, English: the Sixth Star of Mausoleum.).[15]


  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
  2. ^ a b c d Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N
  3. ^ a b Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal, 104 (1): 275–313, Bibcode:1992AJ....104..275E, doi:10.1086/116239
  4. ^ a b c Ragland, S.; et al. (November 2006), "First Surface-resolved Results with the Infrared Optical Telescope Array Imaging Interferometer: Detection of Asymmetries in Asymptotic Giant Branch Stars", The Astrophysical Journal, 652 (1): 650–660, arXiv:astro-ph/0607156, Bibcode:2006ApJ...652..650R, doi:10.1086/507453
  5. ^ Famaey, B.; et al. (May 2009), "Spectroscopic binaries among Hipparcos M giants. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv:0901.0934, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698, S2CID 18739721
  6. ^ a b Yeşilyaprak, C.; Aslan, Z. (December 2004), "Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes", Monthly Notices of the Royal Astronomical Society, 355 (2): 601–607, Bibcode:2004MNRAS.355..601Y, doi:10.1111/j.1365-2966.2004.08344.x
  7. ^ a b c Kallinger, T.; et al. (April 2019), "Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE-Constellation", Astronomy & Astrophysics, 624: 17, arXiv:1902.07531, Bibcode:2019A&A...624A..35K, doi:10.1051/0004-6361/201834514, A35.
  8. ^ Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209
  9. ^ a b c Kaler, James B., "GORGONEA TERTIA (Rho Persei)", Stars, University of Illinois, retrieved 2012-01-25
  10. ^ "rho Per -- Semi-regular pulsating Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-01-24
  11. ^ Allen, Richard Hinckley (1899), "Star-names and their meanings", New York, G. E. Stechert: 334, Bibcode:1899sntm.book.....A
  12. ^ Kukarkin, B. V.; et al. (1971), General Catalogue of Variable Stars (3rd ed.), Bibcode:1971GCVS3.C......0K
  13. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16
  14. ^ Cox, Arthur N.; Becker, Stephen A.; Pesnell, W. Dean (2000), "Chapter 20. Theoretical Stellar Evolution" (PDF), Allen's astrophysical quantities (4th ed.), New York: Springer, p. 516, ISBN 0-387-98746-0, retrieved 2012-01-25 See table 20.5
  15. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日

External links

  • Gorgonea Tertia