| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Leo |
| Right ascension | 11h 35m 51.52322s[1] |
| Declination | −04° 45′ 20.5046″[1] |
| Apparent magnitude (V) | 8.42[2] |
| Characteristics | |
| Spectral type | G8V[3] |
| B−Vcolor index | 0.76±0.02[2] |
| Astrometry | |
| Radial velocity (Rv) | 1.10±0.14[1] km/s |
| Proper motion (μ) | RA: −11.535mas/yr[1] Dec.: 35.586mas/yr[1] |
| Parallax (π) | 20.1590±0.0285 mas[1] |
| Distance | 161.8 ± 0.2 ly (49.61 ± 0.07 pc) |
| Absolute magnitude (MV) | 4.95[2] |
| Details[4] | |
| Mass | 1.032+0.042 −0.045 M☉ |
| Radius | 1.033+0.021 −0.018 R☉ |
| Luminosity | 0.946+0.003 −0.004[5] L☉ |
| Surface gravity (log g) | 4.402±0.265 cgs |
| Temperature | 5,611±42 K |
| Metallicity[Fe/H] | 0.330±0.096 dex |
| Rotational velocity (v sin i) | 1.676±0.230 km/s |
| Age | 4.78+2.20 −2.14 Gyr |
| Other designations | |
| Sagarmatha,BD–03°3147,HD 100777,HIP 56572,SAO 138288,TYC 4933-678-1,2MASS J11355152-0445204[6] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 100777 is a single[7] star with a planetary companion in theequatorialconstellation ofLeo.[8] With anapparent visual magnitude of 8.42 it is too faint to be viewed with the naked eye, although theabsolute magnitude of 4.81 indicates it could be seen if it were just 33 ly (10 pc) away. The distance to the star is approximately 162light-years based onparallax measurements.
TheInternational Astronomical Union held theNameExoWorlds campaign in 2019.Nepal named the starSagarmatha, the Nepali name ofMount Everest, and the exoplanet revolving it was named asLaligurans, the Nepali name of the flowerRhododendron.[9]
This is an ordinaryG-type main-sequence star with astellar classification of G8V.[3] It has a similar mass, size, and luminosity to the Sun. The star is roughly five[4] billion years old with aninactive chromosphere[8] and is spinning with aprojected rotational velocity of 1.7 km/s.[4] A 2015 survey ruled out the existence of any additional stellar companions at projected distances from 18 to 369astronomical units.[7]
In 2007, a giantexoplanet companion was found using theradial velocity method. It is orbiting HD 100777 at a distance of1.03 AU with aperiod of 384 days and aneccentricity (ovalness) of 0.36. The inclination of theorbital plane of this body is unknown, so only a lower limit on the mass can be determined. It has at least 1.16 times themass of Jupiter.[8]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Laligurans | >1.16 ± 0.03 MJ | 1.03 ± 0.03 | 383.7 ± 1.2 | 0.36 ± 0.02 | — | — |
