HD 41248
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Pictor |
| Right ascension | 06h 00m 32.78130s[1] |
| Declination | −56° 09′ 42.6031″[1] |
| Apparent magnitude (V) | 8.81 |
| Characteristics | |
| Spectral type | G1V[2] |
| Astrometry | |
| Proper motion (μ) | RA: 125.88[1] mas/yr Dec.: 58.53[1] mas/yr |
| Parallax (π) | 19.09 ± 0.71 mas[1] |
| Distance | 171 ± 6 ly (52 ± 2 pc) |
| Absolute magnitude (MV) | 5.23[3] |
| Details | |
| Mass | 0.94 ± 0.02[3] M☉ |
| Radius | 0.92 ± 0.06[3] R☉ |
| Luminosity | 0.70[3] L☉ |
| Surface gravity (log g) | 4.49 ± 0.05[3] cgs |
| Temperature | 5713 ± 21[3] K |
| Metallicity [Fe/H] | −0.37 ± 0.05[3] dex |
| Rotation | 26.4±1.1 d[2] |
| Rotational velocity (v sin i) | 1.0[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 41248 is a star in the constellation Pictor.[4] It is a star very similar to the Sun, with the same spectral type (G2V). It has 68% of the Sun's luminosity, 92% of its mass and 78% of its diameter. It is estimated to be around 2 billion years old, and it has a lower metallicity—43% that of the Sun.[5] With an apparent visual magnitude of 8.81,[4] it is too faint to be seen with the unaided eye,[6] and is located around 170 light-years (52 parsecs) away from the Solar System.[5]
HD 41248 was investigated in the High Accuracy Radial Velocity Planet Searcher (HARPS) and initially thought not to have planets, but review of its spectrum showed it to have two super-earths with orbital periods of 18.357 days and 25.648 days and minimum masses 12.3 and 8.6 times that of the Earth. The planets are in a 7:5 mean motion resonance.[5] The existence of the planets has been called into question as being a possible false detection due to stellar activity, with a cycle of 25 days related to the star's rotational period.[3] The original researchers conceded small planet signals could be difficult to unravel from signal noise and noted that the star had become more active in recent years, but in reanalysing all the data concluded that the stability of the radial velocity signals over ten years strengthened the case for the planet hypothesis. They add that more conclusive proof could come as instruments operating in the near infrared such as CARMENES or the Habitable Zone Planet Finder (HPF) become operational.[7]
References
[edit]- ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b Suárez Mascareño, A.; et al. (September 2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society, 452 (3): 2745–2756, arXiv:1506.08039, Bibcode:2015MNRAS.452.2745S, doi:10.1093/mnras/stv1441.
- ^ a b c d e f g h i N.C. Santos; A. Mortier; J. P. Faria; X. Dumusque; V. Zh. Adibekyan; E. Delgado-Mena; P. Figueira; L. Benamati; I. Boisse; D. Cunha; J. Gomes da Silva; G. Lo Curto; C. Lovis; J. H. C. Martins; M. Mayor; C. Melo; M. Oshagh; F. Pepe; D. Queloz; A. Santerne; D. Segransan; A. Sozzetti; S. G. Sousa; S. Udry (2014-04-24). "The HARPS search for southern extra-solar planets XXXV. The interesting case of HD41248: stellar activity, no planets?". Astronomy & Astrophysics. 566: A35. arXiv:1404.6135. Bibcode:2014A&A...566A..35S. doi:10.1051/0004-6361/201423808. S2CID 118668716.
- ^ a b c "HD 41248". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 July 2014.
- ^ a b c Jenkins, J. S.; Tuomi, M.; Brasser, R.; Ivanyuk, O.; Murgas, F. (2013). "Two Super-Earths Orbiting the Solar Analog HD 41248 on the Edge of a 7:5 Mean Motion Resonance". The Astrophysical Journal. 771 (1): 41. arXiv:1304.7374. Bibcode:2013ApJ...771...41J. doi:10.1088/0004-637X/771/1/41. S2CID 14827197. 41, 13 pp.
- ^ Bortle, John E. (February 2001). "The Bortle Dark-Sky Scale". Sky & Telescope. Sky Publishing Corporation. Archived from the original on 31 March 2014. Retrieved 10 July 2014.
- ^ James S. Jenkins; Mikko Tuomi (2014-06-12). "The curious case of HD41248. A pair of static signals buried behind red-noise". The Astrophysical Journal. 794 (2): 110. arXiv:1406.3093. Bibcode:2014ApJ...794..110J. doi:10.1088/0004-637X/794/2/110. S2CID 13397207.
