Rho Puppis (ρ Puppis, abbreviated Rho Pup, ρ Pup), formally named Tureis , is a

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Puppis Puppis is a constellation in the southern sky. Puppis, the Latin translation of "poop deck", was originally part of an over-large constellation Argo Navis (the ship of Jason and the Argonauts), which centuries after its initial description, was ...

. With an average apparent visual magnitude of 2.78, it is the third-brightest member of this generally faint constellation. Based upon

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

measurements made during the

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...

mission, Rho Puppis is located at a distance of from the Sun. It is the prototype of the ρ Puppis class of evolved Am stars.

Nomenclature

''ρ Puppis'' ( Latinised to ''Rho Puppis'') is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

. It bore the traditional name ''Tureis'' or ''Turais'', from the Arabic ''تُرَيْس'' ''turays'' "shield" (

diminutive A diminutive is a root word that has been modified to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment. A (abbreviated ) is a word-formati ...

), which was shared by Iota Carinae. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name ''Tureis'' for this star on 12 September 2016 and it is now so entered in the IAU Catalog of Star Names (Iota Carinae was given the name ''Aspidiske'' on 20 July 2016).

Properties

At present Rho Puppis is moving away from the Sun with a

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

of +46.1 km s⁻¹. The closest approach occurred about 394,000 years ago when it came within roughly of the Solar System; about the same distance as Procyon in the present era. The variability of this star was announced in 1956 by American astronomer

Olin J. Eggen Olin Jeuck Eggen (July 9, 1919 – October 2, 1998) was an American astronomer. Biography Olin Jeuck Eggen was born to Olin Eggen and Bertha Clare Jeuck in the village of Orfordville in Rock County, Wisconsin. Both of his parents were of Norw ...

. It was determined to be a Delta Scuti-type variable star, making it one of the first stars of that type to be identified. Photometric observations dating back to 1946 provide a lengthy record of its pattern of pulsation; it undergoes periodic pulsations with a single period of 0.14088143(3) days, or 7.1 cycles per day. During each cycle, the star's magnitude varies with an amplitude of 0.15 and the radial velocity varies by 10 km s⁻¹. The peak brightness occurs 28.8 minutes following the minimum radial velocity. The outer atmosphere's

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 6,920 K is one of the lowest known for a Delta Scuti variable. Rho Puppis has an estimated age of about 2 billion years and it has 3.4 times the Sun's radius. It has a stellar classification of F5IIkF2IImF5II. This complex format indicates that ρ Puppis is an Am star, with relatively weak lines of calcium and strong lines of other metals. The spectral type indicated by the calcium k line is F5, while that indicated by heavier metal

absorption line A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...

s is F2. The roman numerals indicate a luminosity class of bright giant. Most such stars are found in binary star systems, but this appears to be an exception as no companion has been discovered. Evolved stars with Am-like peculiarities of abundance have come to be known as ρ Puppis stars. The star's

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

is more than double that in the Sun. This star shows an excess emission of infrared radiation, suggesting that there is a circumstellar disk of dust orbiting this star. The mean temperature of the emission is 85 K, corresponding to an orbital separation from the host star of 50 AU.

References

{{DEFAULTSORT:Rho Puppis Puppis, Rho Puppis Tureis Circumstellar disks Puppis, 15 F-type bright giants Delta Scuti variables 039757 3185 067523 Durchmusterung objects