HD 48948 is a K-type main-sequence star located in the constellation Lynx, approximately 55 light years away, based on a parallax of 59.393 mas. At an apparent magnitude of 8.58, it is too faint to be seen with the naked eye.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Lynx |
| Right ascension | 06h 49m 57.57s[1] |
| Declination | +60° 20′ 14.53″[1] |
| Apparent magnitude (V) | 8.58[2] |
| Characteristics | |
| Evolutionary stage | Main sequence star |
| Spectral type | K3V[3] |
| Apparent magnitude (J) | 6.33±0.02[2] |
| Apparent magnitude (H) | 5.73±0.02[2] |
| Apparent magnitude (K) | 5.61±0.02[2] |
| B−V color index | 1.21[2] |
| Astrometry | |
| Radial velocity (Rv) | −52.061±0.0020[3] km/s |
| Proper motion (μ) | RA: 253.401±0.020 mas/yr[3] Dec.: 410.798±0.017 mas/yr[3] |
| Parallax (π) | 59.393 ± 0.025 mas[2] |
| Distance | 54.91 ± 0.02 ly (16.837 ± 0.007 pc) |
| Absolute magnitude (MV) | 7.46±0.05[4] |
| Details[2] | |
| Mass | 0.686+0.020 −0.013 M☉ |
| Radius | 0.679±0.004 R☉ |
| Luminosity | 0.156[5] L☉ |
| Temperature | 4593±60 K |
| Metallicity [Fe/H] | −0.21±0.03 dex |
| Rotation | 43.45+1 −0.71 d |
| Rotational velocity (v sin i) | <2 km/s |
| Age | 11.48+1.93 −4.67 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
It has a stellar classification of K3V, which classifies it as a main sequence star (like our Sun) fusing atoms of hydrogen into helium at its core. Estimated to be 11.5 billion years old, HD 48948 has 0.68 times the mass and the radius of the Sun. Its surface has an effective temperature of 4,593 K,[2] giving it the orange glow of a K-type star.[6]
Planetary system
editIn 2024, three planets were discovered orbiting HD 48948 via radial velocity using the HARPS-N spectrograph, with orbital periods of 7.3, 38 and 151 days, respectively,[7] derived from 189 measurements over a 9.5-year period from 6 October 2013 to 16 April 2023. Of the three planets, the outermost planet, HD 48948 d, a super-Earth weighing 10.59±1.00 Earth masses, is located within the habitable zone.[8] It is the nearest known super-Earth orbiting within the habitable zone of an F-, G- or K-type star, with the only other nearby examples being HIP 38594 b and HD 216520 c.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >4.88±0.21 M🜨 | 0.0652±0.0005 | 7.34013±0.00040 | 0.078+0.058 −0.050 |
— | — |
| c | >7.27±0.70 M🜨 | 0.1951±0.0016 | 37.920+0.026 −0.024 |
0.22+0.10 −0.11 |
— | — |
| d | >10.59±1.00 M🜨 | 0.4894±0.0042 | 150.95+0.45 −0.41 |
0.12+0.12 −0.08 |
— | — |
References
edit- ^ a b Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g h i j k Dalal, S.; et al. (37) (24 June 2024). "Trio of super-Earth candidates orbiting K-dwarf HD 48948: a new habitable zone candidate". Monthly Notices of the Royal Astronomical Society. 531 (4): 4464–4481. doi:10.1093/mnras/stae1367. Retrieved 9 July 2024.
- ^ a b c "HD 48948". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 9 July 2024.
- ^ Holmberg, J.; Nordström, B.; Andersen, J. (2009-07-01). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics. 501: 941–947. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191. ISSN 0004-6361. HD 48948's database entry at VizieR.
- ^ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society, 471: 770–791, arXiv:1706.02208, doi:10.1093/mnras/stx1433, ISSN 0035-8711 HD 48948' database entry at VizieR.
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2013-12-03, retrieved 2012-01-16
- ^ Cowing, Keith (26 June 2024). "Three Potential Super-Earths Discovered Around Nearby Star HD 48 948". Astrobiology. Retrieved 11 July 2024.
- ^ Luntz, Stephen (25 June 2024). "Nearest Super-Earth In A Habitable Zone Orbit Announced". IFLScience. Retrieved 11 July 2024.