Kappa Cancri

Kappa Cancri
Location of κ Cancri (circled)

A light curve for Kappa Cancri, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer
Right ascension 09h 07m 44.80955s[2]
Declination +10° 40′ 05.5196″[2]
Apparent magnitude (V) +5.233[3]
Characteristics
Spectral type B8 IIIp[4]
B−V color index −0.113[3]
Variable type α2 CVn[5]
Astrometry
Proper motion (μ) RA: −18.31[2] mas/yr
Dec.: −12.105[2] mas/yr
Parallax (π)5.3209 ± 0.1298 mas[2]
Distance610 ± 10 ly
(188 ± 5 pc)
Absolute magnitude (MV)−0.82[6]
Orbit[7]
Period (P)6.3933 d
Eccentricity (e)0.13
Periastron epoch (T)2440001.95 JD
Argument of periastron (ω)
(secondary)		157°
Semi-amplitude (K1)
(primary)		67.4 km/s
Details[8]
κ Cnc A
Mass4.5 M☉
Radius5.0 R☉
Luminosity322[6] L☉
Surface gravity (log g)3.7±0.1[3] cgs
Temperature12,800±200[3] K
Metallicity [Fe/H]+0.51[6] dex
Rotational velocity (v sin i)6±2[3] km/s
κ Cnc B
Mass2.1 M☉
Radius2.4 R☉
Surface gravity (log g)4.0 cgs
Temperature8,500 K
Rotational velocity (v sin i)40 km/s
Other designations
κ Cnc, 76 Cancri, BD+11°1984, FK5 1238, HD 78316, HIP 44798, HR 3623, SAO 98378[9]
Database references
SIMBADdata

Kappa Cancri, Latinized from κ Cancri, is a blue-white hued binary star system in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.23.[3] The magnitude difference between the two stars is about 2.6.[10] Based upon an annual parallax shift of 5.3209 mas as seen from the Earth,[2] the system is located roughly 610 light-years from the Sun.

This is a single-lined spectroscopic binary[3] star system with an orbital period of 6.39 days and an eccentricity of 0.13.[7] The primary, component A, has a stellar classification of B8 IIIp,[4] suggesting it is a B-type giant star. It a mercury-manganese star, a type of chemically peculiar star showing large overabundances of those two elements in the outer atmosphere.[3] It is classified as an Alpha2 Canum Venaticorum type variable star and its brightness varies from magnitude +5.22 to +5.27 with a period of five days.[5]

The primary component has 4.5 times the mass of the Sun, five times the Sun's radius, and an effective temperature of 13,200 K. The secondary, component B, is a smaller star with 2.1 times the mass and 2.4 times the radius of the Sun, having an effective temperature of 8,500 K.[8]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Maza2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference levato was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Pourbaix2004 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference caosp27_3_319 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Ryabchikova1998 was invoked but never defined (see the help page).