Astronomy:Rho Aquarii

From HandWiki
Short description: Star in the constellation Aquarius
Rho Aquarii
Location of ρ Aquarii (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius[1]
Right ascension  22h 20m 11.917s[2]
Declination −07° 49′ 15.97″[2]
Apparent magnitude (V) +5.34[3]
Characteristics
Spectral type B8 IIIp Mn:Hg:[4]
U−B color index −0.358[3]
B−V color index −0.057[3]
Astrometry
Radial velocity (Rv)−9[5] km/s
Proper motion (μ) RA: +14.803[2] mas/yr
Dec.: +0.472[2] mas/yr
Parallax (π)4.3443 ± 0.1468[2] mas
Distance750 ± 30 ly
(230 ± 8 pc)
Absolute magnitude (MV)−1.78[1]
Orbit[6]
Period (P)220.41±0.10 d
Eccentricity (e)0 (assumed)
Periastron epoch (T)2418548.7±7.4 JD
Semi-amplitude (K1)
(primary)
18.66±2.75 km/s
Details
A
Mass4.63±0.25[7] M
Radius5.5[8] R
Luminosity1,023+357−264[7] L
Surface gravity (log g)3.5[8] cgs
Temperature12,454±152[7] K
Metallicity [Fe/H]0.059[8] dex
Rotation6.5633±0.0063 d[7]
Rotational velocity (v sin i)65.0±6.9[7] km/s
Other designations
ρ Aqr, 46 Aquarii, BD−08 5855, GC 31225, HD 211838, HIP 110273, HR 8512, SAO 146023, PPM 206239[9]
Database references
SIMBADdata

Rho Aquarii is a binary star[10] system in the equatorial constellation of Aquarius. Its name is a Bayer designation that is Latinized from ρ Aquarii, and abbreviated Rho Aqr or ρ Aqr. This system is visible to the naked eye as a point of light with an apparent visual magnitude of +5.34.[3] Based upon parallax measurements, this star is located at a distance of approximately 750 light-years (230 parsecs) from the Sun.[2] It is drifting closer with a radial velocity of –9 km/s.[5] The position of this star near the ecliptic means it is subject to lunar occultations.[11]

This is a single-lined spectroscopic binary, with the presence of a companion being revealed by Doppler shifts in the spectrum.[10] An initial orbital solution for the data gives a period of 220.4 days with a circular orbit.[6]

The primary is a non-magnetic chemically peculiar star with a stellar classification of B8 IIIp Mn:Hg:.[4] It is a candidate mercury-manganese star, showing a surfeit of these elements in the spectrum.[10] At least two pulsation periods have been detected; the first is characteristic of a Delta Scuti variable and the second of a Gamma Doradus variable, suggesting this is a hybrid pulsator.[7] The dominant pulsation period is 1.1203±0.0002 d.[12] With 4.63 times the Sun's mass, this star is radiating 1,023 times as much luminosity from its outer atmosphere at an effective temperature of 12,454 K.[7] This heat gives it the blue-white hue of a B-type star.[13] It is spinning with a rotation period of 6.5633±0.0063 d.[7] The primary does not display photometric variability, but the companion may be a variable star.[14] Although no specific age estimates have been published for this star, it is likely to be less than 50 million years old.[15]

References

  1. 1.0 1.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  2. 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars 8: 59, Bibcode1984SAAOC...8...59C. 
  4. 4.0 4.1 Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode2002ApJ...573..359A. 
  5. 5.0 5.1 Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington), Bibcode1953GCRV..C......0W. 
  6. 6.0 6.1 Stickland, D. J.; Weatherby, J. (July 1984), "Radial velocities of northern mercury stars", Astronomy and Astrophysics, Supplemental Series 57: 55–67, Bibcode1984A&AS...57...55S. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 Paunzen, E. et al. (February 2013), "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society 429 (1): 119–125, doi:10.1093/mnras/sts318, Bibcode2013MNRAS.429..119P. 
  8. 8.0 8.1 8.2 Huber, Daniel; Bryson, Stephen T.; Haas, Michael R.; Barclay, Thomas; Barentsen, Geert; Howell, Steve B.; Sharma, Sanjib; Stello, Dennis et al. (2016), "The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8", The Astrophysical Journal Supplement Series 224 (1): 2, doi:10.3847/0067-0049/224/1/2, Bibcode2016ApJS..224....2H. 
  9. "* rho Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+rho+Aqr. 
  10. 10.0 10.1 10.2 Makaganiuk, V. et al. (January 2011), "The search for magnetic fields in mercury-manganese stars", Astronomy and Astrophysics 525: A97, doi:10.1051/0004-6361/201015666, Bibcode2011A&A...525A..97M. 
  11. Hilaire, G. (March 1974), "Observations of occultations of stars by the moon", Astronomy and Astrophysics Supplement 13: 395, Bibcode1974A&AS...13..395H.  See the SAO 146023 entry on p. 402.
  12. Bowman, D. M. et al. (August 2018), "K2 space photometry reveals rotational modulation and stellar pulsations in chemically peculiar A and B stars", Astronomy & Astrophysics 616: id. A77, doi:10.1051/0004-6361/201833037, Bibcode2018A&A...616A..77B. 
  13. "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16 
  14. Adelman, S. J.; Young, K. J. (January 2005), "uvby FCAPT photometry of the mCP stars HR 2258, MW Vul, and HR 9017 and the HgMn star 46 ρ Aqr", Astronomy and Astrophysics 429: 317–322, doi:10.1051/0004-6361:20041118, Bibcode2005A&A...429..317A. 
  15. Kerr, Ronan M. P.; Rizzuto, Aaron C.; Kraus, Adam L.; Offner, Stella S. R. (2021), "Stars with Photometrically Young Gaia Luminosities Around the Solar System (SPYGLASS). I. Mapping Young Stellar Structures and Their Star Formation Histories", The Astrophysical Journal 917 (1): 23, doi:10.3847/1538-4357/ac0251, Bibcode2021ApJ...917...23K.