25 Cancri

This article is about d2 Cancri. For other stars with this Bayer designation, see d Cancri.
25 Cancri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
Right ascension 08h 25m 49.87726s[1]
Declination +17° 02′ 46.5717″[1]
Apparent magnitude (V) 6.11[2]
Characteristics
Spectral type F6 V[3]
B−V color index 0.448±0.005[2]
Astrometry
Radial velocity (Rv)+37.56±0.13[1] km/s
Proper motion (μ) RA: −191.567[1] mas/yr
Dec.: −151.554[1] mas/yr
Parallax (π)21.9803 ± 0.0321 mas[1]
Distance148.4 ± 0.2 ly
(45.50 ± 0.07 pc)
Absolute magnitude (MV)2.85[2]
Details
25 Cnc A
Mass1.51[4] M☉
Radius2.0[1] R☉
Luminosity6.60[2] L☉
Surface gravity (log g)4.01[5] cgs
Temperature6,487[5] K
Metallicity [Fe/H]−0.10[5] dex
Rotational velocity (v sin i)37.74±0.55[6] km/s
Age2.50[5] Gyr
25 Cnc B
Mass0.34[4] M☉
Other designations
d2 Cnc, 25 Cnc, BD+17°1842, HD 71030, HIP 41319, HR 3299, SAO 97806, WDS 08258+1703[7][8]
Database references
SIMBADdata

25 Cancri is a common proper motion[4] star system in the zodiac constellation of Cancer, located around 148 light-years away from the Sun. It has the Bayer designation d2 Cancri (d2 Cnc); 25 Cancri (25 Cnc) is the Flamsteed designation. It is near the lower limit of visibility to the naked eye in good viewing conditions, appearing as a dim, yellow-white-hued star with a combined apparent visual magnitude of 6.11.[2] The pair have a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.245″ per year.[9] It is moving further from the Earth with a heliocentric radial velocity of +38 km/s.[1]

Based upon a stellar classification of F6 V,[3] the brighter component is an F-type main-sequence star that is generating energy through hydrogen fusion at its core. Cowley (1976) listed a class of F5 IIIm?,[10] which suggests it may be an Am star. However, this has not been confirmed.[6] It is about 2.5[5] billion years old with 1.51[4] times the mass of the Sun. The star is radiating 6.6[2] times the Sun's luminosity from its photosphere at an effective temperature of 6,487 K.[5]

The companion is 4.19 magnitudes fainter than the primary, and lies at an angular separation of 16.798″ along a position angle of 310°, as of 2013.[8] If the pair are gravitationally bound, then they orbit each other with a period of around 4.05 million years.[4]

  1. ^ a b c d e f g h Cite error: The named reference dr3 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Harlan1969 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference tokovinin2014 was invoked but never defined (see the help page).
  5. ^ a b c d e f Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference LeBlanc2015 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Riddle2015 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Lepine2005 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Cowley1976 was invoked but never defined (see the help page).