Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Orion |
Right ascension | 06h 12m 00.567s[1] |
Declination | +06° 46′ 59.06″[1] |
Apparent magnitude (V) | 6.85[2] |
Characteristics | |
Evolutionary stage | Main sequence |
Spectral type | G4V[3] |
B−V color index | 0.642±0.007[2] |
Astrometry | |
Radial velocity (Rv) | −53.52±0.14[4] km/s |
Proper motion (μ) | RA: 197.247 mas/yr[1] Dec.: −254.867 mas/yr[1] |
Parallax (π) | 40.9764 ± 0.0240 mas[1] |
Distance | 79.60 ± 0.05 ly (24.40 ± 0.01 pc) |
Absolute magnitude (MV) | 5.03±0.06[3] |
Details | |
Mass | 0.92±0.02[5] M☉ |
Radius | 0.94[5] R☉ |
Luminosity | 0.918±0.012[5] L☉ |
Surface gravity (log g) | 4.44±0.01[6] cgs |
Temperature | 5,758±5 K[6] 5,765±17[5] K |
Metallicity [Fe/H] | −0.096±0.005 dex[6] −0.10±0.02[5] dex |
Rotation | 16.9 d[7] |
Rotational velocity (v sin i) | 1.83±0.11[6] km/s |
Age | 5.51±0.71 Gyr[6] 5.5±0.2[5] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 42618 is a well-studied[7] star with an exoplanetary companion in the equatorial constellation of Orion. With an apparent visual magnitude of 6.85[2] it is too faint to be readily visible to the naked eye. This system is located at a distance of 79.6 light years from the Sun based on parallax measurements. It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.321″ per year.[9] HD 42618 is drifting closer with a radial velocity of −53.5[4] km/s and is predicted to come as near as 42.6 light-years in around 297,000 years.[2]
The stellar classification of HD 42618 is G4V,[3] which shows it to be an ordinary G-type main-sequence star. It is considered a close solar analog, which means the physical properties of the star are particularly similar to those of the Sun.[10] Seismic model indicates the star is older and more evolved than the Sun with an age of about 5.5 billion years.[5] It is spinning with a low projected rotational velocity of 1.8 km/s,[6] with the rotation rate being consistent with the star's low activity level.[11] The star has 92% of the mass of the Sun and 94% of the Sun's radius. The surface metallicity is lower than in the Sun,[5] with the abundance patterns being consistent with a solar-type star.[11] HD 42618 is radiating 92% of the luminosity of the Sun from its photosphere at an effective temperature of 5,765 K.[5]
In 2016, the discovery of a candidate exoplanet companion orbiting HD 42618 was announced. Designated HD 42618 b, it was found using the radial velocity method which showed a periodicity of 149.6 days. The orbital elements have the planet orbiting at a distance of 0.55 AU from the host star with an orbital eccentricity (ovalness) of 0.2 and a Neptune-like mass. A second signal with a period of 388 days was detected, but this is unconfirmed and may be false. A 4,850 day signal is likely the result of star's magnetic activity cycle.[7]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥ 14.4+2.5 −2.4 M🜨 |
0.554±0.011 | 149.61+0.37 −0.34 |
0.19+0.15 −0.12 |
— | — |
References
[edit]- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c d Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c Medhi, B. J.; et al. (July 2007), "Results from a spectroscopic survey in the CoRoT fields. I. Search for chromospherically active stars", Astronomy and Astrophysics, 469 (2): 713–719, Bibcode:2007A&A...469..713M, doi:10.1051/0004-6361:20054173.
- ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g h i Castro, M.; et al. (August 2021), "Modeling of two CoRoT solar analogues constrained by seismic and spectroscopic analysis", Monthly Notices of the Royal Astronomical Society, 505 (2): 2151–2158, arXiv:2008.01163, Bibcode:2021MNRAS.505.2151C, doi:10.1093/mnras/stab1410.
- ^ a b c d e f dos Santos, Leonardo A.; et al. (August 2016), "The Solar Twin Planet Search. IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars", Astronomy & Astrophysics, 592: 8, arXiv:1606.06214, Bibcode:2016A&A...592A.156D, doi:10.1051/0004-6361/201628558, S2CID 53533614, A156.
- ^ a b c d Fulton, Benjamin J.; et al. (October 2016), "Three Temperate Neptunes Orbiting Nearby Stars", The Astrophysical Journal, 830 (1): 19, arXiv:1607.00007, Bibcode:2016ApJ...830...46F, doi:10.3847/0004-637X/830/1/46, S2CID 36666883, 46.
- ^ "HD 42618", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2022-02-17.
- ^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
- ^ Soubiran, C.; Triaud, A. (May 2004), "The Top Ten solar analogs in the ELODIE library", Astronomy and Astrophysics, 418 (3): 1089–1100, arXiv:astro-ph/0402094, Bibcode:2004A&A...418.1089S, doi:10.1051/0004-6361:20035708.
- ^ a b Morel, T.; et al. (April 2013), "Abundance study of the two solar-analogue CoRoT targets HD 42618 and HD 43587 from HARPS spectroscopy", Astronomy & Astrophysics, 552: 10, arXiv:1302.3172, Bibcode:2013A&A...552A..42M, doi:10.1051/0004-6361/201220883, S2CID 53686102, A42.
Further reading
[edit]- Castro, M.; Baudin, F.; Marques, J.; do Nascimento Jr., J. D. (2018), "The impact of GAIA astrometry on the evolutionary status of the seismic analog HD 42618" (PDF), Boletim da Sociedade Astronômica Brasileira, 30 (1): 93–94, retrieved 2022-02-17.
- Barban, C.; et al. (June 2013), "Solar-like oscillations in distant stars as seen by CoRoT : the special case of HD 42618, a solar sister", Journal of Physics: Conference Series, 440 (1): 012030, Bibcode:2013JPhCS.440a2030B, doi:10.1088/1742-6596/440/1/012030, 012030.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction