HIP 70849

HIP 70849
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lupus
Right ascension 14h 29m 18.56436s
Declination −46° 27 49.7378
Apparent magnitude (V) 10.36
Characteristics
Spectral type K7Vk
Apparent magnitude (B) 11.787
Apparent magnitude (J) 7.639±0.023
Apparent magnitude (H) 7.006±0.061
Apparent magnitude (K) 6.790±0.027
B−V color index 1.427±0.019
Variable type 8.50
Astrometry
Radial velocity (Rv)−0.134±0.0013 km/s
Proper motion (μ) RA: −44.051±0.017 mas/yr
Dec.: −201.577±0.020 mas/yr
Parallax (π)41.4618±0.0175 mas
Distance78.66 ± 0.03 ly
(24.12 ± 0.01 pc)
Absolute magnitude (MV)8.5
Details
Mass0.63±0.03
0.76±0.07 M
Radius0.62±0.02 R
Luminosity (bolometric)0.0892±0.0005 L
Surface gravity (log g)3.70±0.09 cgs
Temperature4,103±25 K
Metallicity [Fe/H]0.00±0.03 dex
Rotation41.2 d
Rotational velocity (v sin i)1.93 km/s
0.30±0.30 km/s
Age3.6±0.15 Gyr
Other designations
NSV 6678, CD−45°9206, GJ 550.3, HIP 70849, PPM 760399, LTT 5717, NLTT 37446
Database references
SIMBADdata
Exoplanet Archivedata

HIP 70849 is a star with two non-stellar companions in the southern constellation Lupus. It is a 10th magnitude star, making it too faint to be visible to the naked eye. The system is located at a distance of 78.7 light-years from the Sun based on parallax measurements.

This is a K-type main-sequence star with a stellar classification of K7Vk, where the 'k' indicates interstellar absorption features in the spectrum. The star is magnetically active with a 10.1±1.4 yr starspot cycle. It appears about 3.6 billion years old and the light emission shows a 41.2 day periodicity, which is likely the rotation period. This star, which resembles a brighter red dwarf, is smaller and less massive than the Sun. It is radiating just 9% of the luminosity of the Sun from its photosphere at an effective temperature of 4,103 K.

In 2009, a gas giant planet was found in orbit around it. Designated HIP 70849 b, it has 4.5 times the mass of Jupiter and takes more than 3000 days to orbit at a semimajor axis of 3.99 AU, with a high eccentricity. There is also a T4.5 brown dwarf companion orbiting ~9000AU from HIP 70849.

The HIP 70849 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 4.5+0.4
−0.3
 MJ
3.99+0.06
−0.07
3649±18 0.65+0.02
−0.01
96±16°