| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Major[1] |
| Right ascension | 08h 18m 22.17286s[2] |
| Declination | +61° 27′ 38.5950″[2] |
| Apparent magnitude (V) | 8.20[1] |
| Characteristics | |
| Spectral type | G0V[3] or G2V[4] or G2IV[1] |
| B−Vcolor index | 0.652±0.015[1] |
| Astrometry | |
| Radial velocity (Rv) | −69.45±0.11[1] km/s |
| Proper motion (μ) | RA: 128.266mas/yr[2] Dec.: 30.427mas/yr[2] |
| Parallax (π) | 16.5598±0.0221 mas[2] |
| Distance | 197.0 ± 0.3 ly (60.39 ± 0.08 pc) |
| Absolute magnitude (MV) | 4.52[1] |
| Details[5] | |
| Mass | 1.16±0.01 M☉ |
| Radius | 1.08±0.01 R☉ |
| Luminosity | 1.297±0.002 L☉ |
| Surface gravity (log g) | 4.42±0.01 cgs |
| Temperature | 5919±11 K |
| Metallicity[Fe/H] | 0.29±0.01[1] dex |
| Rotational velocity (v sin i) | 6.4[6] km/s |
| Age | 1.0±0.4 Gyr |
| Other designations | |
| Násti,BD+61°1038,HD 68988,HIP 40687,SAO 14494[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 68988 is astar in the northernconstellation ofUrsa Major. It has the proper nameNásti, which means star in the NorthernSami language. The name was selected in theNameExoWorlds campaign byNorway, during the 100th anniversary of theIAU.[8][9] HD 68988 is too faint to be seen with the naked eye, having anapparent visual magnitude of 8.20.[1] The star is located at a distance of 197 light-years from theSun based onparallax. It is drifting closer with aradial velocity of −69 km/s and is predicted to come as close as 78 light-years in 617,000 years.[1]
Thestellar classification of HD 68988 has been given as G0V,[3] G2V,[4] and G2IV.[1] The age of this star was estimated as six billion years in 2002,[4] but was later revised down to one billion years in 2015.[5] It is rotating slowly and ischromospherically inactive.[10] The star has 16% more mass than the Sun and an 8% greater radius with a highmetallicity; what astronomers term the abundance of heavier elements. It is radiating 1.3 times theluminosity of the Sun from itsphotosphere at aneffective temperature of 5,919 K.[5]
There are twoexoplanets:HD 68988 b was discovered in 2002[4] andHD 68988 c was discovered in 2006.[11] The orbit of the inner exoplanet is surprisingly eccentric for such a close in orbit, and over time it may become circularized,[10] although orbital parameters were significantly revised in 2021, resulting in wider orbit.[12] In 2025, the true mass of the planet was measured usingastrometry, consistent with that of Rosenthalet al. (2021).[13]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (years) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Albmi | >1.972+0.017 −0.018 MJ | 0.0710+0.0012 −0.0014 | 0.017183893(34) | 0.1533+0.0049 −0.0048 | — | — |
| c | 15.03+0.90 −0.75 MJ | 12.1±1.1 | 38.1+5.3 −4.9 | 0.399+0.046 −0.049 | 93+19 −23° | — |
