Rho Virginis

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Rho Virginis
Diagram showing star positions and boundaries of the Virgo constellation and its surroundings
Cercle rouge 100%.svg

Location of ρ Virginis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Virgo
Right ascension 12h 41m 53.05658s[1]
Declination +10° 14′ 51.1699″[1]
Apparent magnitude (V) +4.88[2]
Characteristics
Spectral type A0 V[3]
U−B color index +0.03[4]
B−V color index +0.09[4]
Astrometry
Radial velocity (Rv) +1.6[2] km/s
Proper motion (μ) RA: +82.67[1] mas/yr
Dec.: –89.08[1] mas/yr
Parallax (π) 27.57 ± 0.21[1] mas
Distance 118.3 ± 0.9 ly
(36.3 ± 0.3 pc)
Details
Mass 2.0[5] M
Radius 1.6[5] R
Luminosity 14[5] L
Surface gravity (log g) 4.36[6] cgs
Temperature 8,930[5] K
Metallicity [Fe/H] –1.00[6] dex
Rotational velocity (v sin i) 154[7] km/s
Other designations
30 Virginis, BD+11 2485, FK5 1326, HD 110411, HIP 61960, HR 4828, SAO 100211.

Rho Virginis (ρ Vir, ρ Virginis) is the Bayer designation for a star in the constellation Virgo. It has an apparent visual magnitude of +4.9,[2] making it a challenge to view with the naked eye from an urban area (according to the Bortle Dark-Sky Scale). The distance to this star has been measured directly using the parallax method, which places it 118.3 light-years (36.3 parsecs) away with a margin of error of about a light year.[1]

Rho Virginis is an A-type main sequence star with a stellar classification of A0 V.[3] It is larger than the Sun with a radius 60%[5] larger and about twice the mass. As such it is generating energy at a higher rate than the Sun, with a luminosity 14[5] times greater. The outer atmosphere has an effective temperature of 8,930 K,[5] which is what gives it the white-hued glow of an A-type star. It is classified as a Delta Scuti type variable star and its brightness varies by 0.02 magnitudes over periods of 0.5 to 2.4 hours.

This star has been established as a Lambda Boötis star that displays low abundances of iron peak elements. It displays an excess of infrared emission, but it is unclear whether this is being caused by a circumstellar debris disk or from the star passing through and heating up a diffuse interstellar dust cloud. Most likely it is the former,[5] in which case the dusty disk has a radius of around 37 AU and a mean temperature of 90 K.[8]

References[edit]

  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. 
  2. ^ a b c Wielen, R. et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions (35), Astronomisches Rechen-Institut Heidelberg, Bibcode:1999VeARI..35....1W. 
  3. ^ a b Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819. 
  4. ^ a b Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99), Bibcode:1966CoLPL...4...99J. 
  5. ^ a b c d e f g h Martínez-Galarza, J. R. et al. (March 2009), "Infrared Emission by Dust Around λ Bootis Stars: Debris Disks or Thermally Emitting Nebulae?", The Astrophysical Journal 694 (1): 165–173, arXiv:0812.2198, Bibcode:2009ApJ...694..165M, doi:10.1088/0004-637X/694/1/165. 
  6. ^ a b Sturenburg, S. (September 1993), "Abundance Analysis of Lambda-Bootis Stars", Astronomy and Astrophysics 277 (1): 139, Bibcode:1993A&A...277..139S. 
  7. ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224. 
  8. ^ Zuckerman, B.; Song, Inseok (March 2004), "Dusty Debris Disks as Signposts of Planets: Implications for Spitzer Space Telescope", The Astrophysical Journal 603 (2): 738–743, arXiv:astro-ph/0311546, Bibcode:2004ApJ...603..738Z, doi:10.1086/381700.