  | |
| Observation data EpochJ2000.0 EquinoxJ2000.0 | |
|---|---|
| Constellation | Puppis |
| k1 Pup | |
| Right ascension | 07h 38m 49.380s[1] |
| Declination | −26° 48′ 06.49″[1] |
| Apparent magnitude (V) | +4.50[2] |
| k2 Pup | |
| Right ascension | 07h 38m 49.869s[1] |
| Declination | −26° 48′ 13.80″[1] |
| Apparent magnitude (V) | +4.429[1] |
| Characteristics | |
| k1 | |
| Spectral type | B6 V[3] |
| k2 | |
| Spectral type | B5 IV[3] |
| Variable type | SX Ari[4] |
| Astrometry | |
| Parallax (π) | 9.41±0.80 mas[5] |
| Distance | 350 ± 30 ly (106 ± 9 pc) |
| k1 | |
| Absolute magnitude (MV) | −1.19[6] |
| k2 | |
| Absolute magnitude (MV) | −0.94[6] |
| Details[6] | |
| k1 | |
| Mass | 4.3±0.3 M☉ |
| Radius | 3.7+1.2 −0.6 R☉ |
| Luminosity | 490 L☉ |
| Surface gravity (log g) | 4.24±0.15 cgs |
| Temperature | 13,600±1,200 K |
| Rotational velocity (v sin i) | 114±5 km/s |
| k2 | |
| Mass | 6.0±0.3 M☉ |
| Radius | 3.0+0.7 −0.3 R☉ |
| Luminosity | 1,202 L☉ |
| Surface gravity (log g) | 4.10±0.15 cgs |
| Temperature | 18,500±500 K |
| Rotational velocity (v sin i) | 61±5 km/s |
| Other designations | |
| HIP 37229,CD−26 4707, NSV 3673 | |
| k1:HR 2948,HD 61555,SAO 174198 | |
| k2:HR 2949,HD 61556,SAO 174199 | |
| Database references | |
| SIMBAD | k Puppis |
| k1 | |
| k2 | |
k Puppis (k Pup, k Puppis) is aBayer designation given to anoptical double star in theconstellationPuppis, the two components beingk1 Puppis andk2 Puppis.
Note that the Bayer designation for this star is "k" not "kappa" (κ). In Bayer's originalUranometria, k Puppis was listed as ρ (rho) Navis.[7] WhenLacaille broke apart the large constellationArgo Navis intoCarina, Puppis, andVela, he re-designated the stars withGreek letters in a single sequence across all three constellations. Additionally, Lacaille usedLatin letters for many additional stars.κ (kappa) is in the constellation of Vela and so there is no kappa in Puppis.[8] The confusion also extends to the proper name Markab which properly applies to κ Velorum (andother stars) but which has also been used for k Puppis when it is called κ Puppis.[9]
Both k1 Puppis and k2 Puppis are bright blueB-type stars of nearly equal brightness, +4.50 and +4.62, respectively. To thenaked eye, the pair has a combined magnitude of +3.80. On the sky, the two stars are separated by approximately 9.9 seconds of arc along PA 318°. The optical pair can be distinguished easily with a smalltelescope. The component k1 Puppis is abinary star system in its own right, while k2 Puppis is avariable star. Each star within the k Puppis optical pair is between 450 and 470light years fromEarth.
k Puppis is listed in theGeneral Catalogue of Variable Stars as a suspected variable star, but the range and type are not stated. TheInternational Bulletin of Variable Stars has since published research showing that k2 Puppis is the variable component. It is anSX Arietis variable with a period of 1.9093 days which is also the rotational period of the star. The total amplitude is 0.015apparent magnitude.[4]
k2 Puppis is achemically peculiar star with a strong magnetic field. It is classified as aHe-weak star and in addition to a deficit of helium in its spectrum, it shows an overabundance of manyiron peak andrare earth elements. All of its spectral lines show variability, probably due to variations in the chemical makeup of its atmosphere as it rotates.[6]
