rho Aquarii
{{short description|Star in the constellation Aquarius}}
{{Starbox begin}}
{{Starbox image
| image =
{{Location mark
| image=Aquarius IAU.svg
| float=center | width=240 | position=right
| mark=Red circle.svg | mark_width=10 | mark_link=ρ Aqr
| x%=48.7 | y%=42.0
}}
| caption = Location of ρ Aquarii (circled)
}}
{{Starbox observe
| epoch = J2000
| constell = Aquarius
}}
{{Starbox character
| class = {{nowrap|B8 IIIp Mn:Hg:}}
| variable =
}}
{{Starbox astrometry
| prop_mo_ra = +14.803
| prop_mo_dec = +0.472
| parallax = 4.3443
| p_error = 0.1468
}}
{{Starbox orbit
| period =
| period_unitless = {{val|220.41|0.10|u=days}}
| axis =
| axis_unitless =
| eccentricity = 0 (assumed)
| inclination =
| node =
| periastron = {{val|2418548.7|7.4|fmt=none|ul=JD}}
| periarg =
| periarg_primary =
| k1 = 18.66{{±|2.75}}
| k2 =
}}
{{Starbox detail
| component1 = A
| luminosity = 1,023{{±|357|264}}
| temperature = 12,454{{±|152}}
| rotational_velocity = 65.0{{±|6.9}}
| rotation = {{val|6.5633|0.0063|u=days}}
| age_gyr =
}}
{{Starbox catalog
| names = {{odlist | B=ρ Aqr | F=46 Aquarii | BD=−08 5855 | GC=31225 | HD=211838 | HIP=110273 | HR=8512 | PPM=206239 | SAO=146023 }}
}}
{{starbox reference
| Simbad=*+rho+Aqr
}}
{{Starbox end}}
Rho Aquarii is a binary star 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. Based upon parallax measurements, this star is located at a distance of approximately {{Convert|750|ly|pc|abbr=off}} from the Sun. It is drifting closer with a radial velocity of –9 km/s. The position of this star near the ecliptic means it is subject to lunar occultations.
This is a single-lined spectroscopic binary, with the presence of a companion being revealed by Doppler shifts in the spectrum. An initial orbital solution for the data gives a period of 220.4 days with a circular orbit.
The primary is a non-magnetic chemically peculiar star with a stellar classification of {{nowrap|B8 IIIp Mn:Hg:}}. It is a candidate mercury-manganese star, showing a surfeit of these elements in the spectrum. 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. The dominant pulsation period is {{val|1.1203|0.0002|u=days}}. 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. This heat gives it the blue-white hue of a B-type star. It is spinning with a rotation period of {{val|6.5633|0.0063|u=days}}. The primary does not display photometric variability, but the companion may be a variable star. Although no specific age estimates have been published for this star, it is likely to be less than 50 million years old.
References
{{reflist|30em|refs=
{{cite Gaia DR3|2616494287177247232}}
| title=XHIP: An extended hipparcos compilation
| last1=Anderson | first1=E. | last2=Francis | first2=Ch.
| journal=Astronomy Letters
| volume=38 | issue=5 | pages=331 | year=2012
| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015
| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}
{{cite simbad | title=* rho Aqr | access-date=2012-07-04 }}
| title=Radial velocities of northern mercury stars
| last1=Stickland | first1=D. J. | last2=Weatherby | first2=J.
| journal=Astronomy and Astrophysics, Supplemental Series
| volume=57 | pages=55–67 | date=July 1984
| bibcode=1984A&AS...57...55S | postscript=. }}
| title=Observations of occultations of stars by the moon
| last=Hilaire | first=G.
| journal=Astronomy and Astrophysics Supplement
| volume=13 | page=395 | date=March 1974
| bibcode=1974A&AS...13..395H | postscript=.
}} See the SAO 146023 entry on p. 402.
{{citation | postscript=. | display-authors=1
| title=A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars
| last1=Paunzen | first1=E. | last2=Wraight | first2=K. T.
| last3=Fossati | first3=L. | last4=Netopil | first4=M.
| last5=White | first5=G. J. | last6=Bewsher | first6=D.
| journal=Monthly Notices of the Royal Astronomical Society
| volume=429 | issue=1 | pages=119–125 | date=February 2013
| doi=10.1093/mnras/sts318 | doi-access=free
| bibcode=2013MNRAS.429..119P | arxiv=1211.1535 }}
| title=K2 space photometry reveals rotational modulation and stellar pulsations in chemically peculiar A and B stars
| last1=Bowman | first1=D. M. | last2=Buysschaert | first2=B.
| last3=Neiner | first3=C. | last4=Pápics | first4=P. I.
| last5=Oksala | first5=M. E. | last6=Aerts | first6=C.
| display-authors=1 | journal=Astronomy & Astrophysics
| volume=616 | at=id. A77 | date=August 2018
| doi=10.1051/0004-6361/201833037 | arxiv=1805.01799
| bibcode=2018A&A...616A..77B }}
}}
External links
- [http://www.alcyone.de/cgi-bin/search.pl?object=HR8512 HR 8512] {{Webarchive|url=https://web.archive.org/web/20050925034753/http://www.alcyone.de/cgi-bin/search.pl?object=HR8512 |date=2005-09-25 }}
- [http://aladin.u-strasbg.fr/AladinPreview?-c=22+20+11.9165-07+49+15.967&ident=*+rho+Aqr&submit=Aladin+previewer Image Rho Aquarii] {{in lang|en}}
- [http://aladin.u-strasbg.fr/java/nph-aladin.pl?script=get+Aladin+*+rho+Aqr+11arcmin%3Bget+simbad+*+rho+Aqr+11arcmin&from=Simbad4&submit=Aladin+applet Aladin sky atlas, image] {{in lang|en}}
{{Stars of Aquarius}}
{{DEFAULTSORT:Rho Aquarii}}
Category:Mercury-manganese stars
Category:Spectroscopic binaries